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Reference ManualToxi

Single Sensor Gas Detector

651 South Main St.Middletown, CT 06457860-344-1079FAX 860-344-106817SEPT2004P/N: 13-046 Version 3.3

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THE TOXI PERSONAL PORTABLE GAS DETECTORHAS BEEN DESIGNED FOR THE DETECTION ANDMEASUREMENT OF POTENTIALLY HAZARDOUSATMOSPHERIC CONDITIONS

IN ORDER TO ASSURE THAT THE USER ISPROPERLY WARNED OF POTENTIALLYDANGEROUS CONDITIONS, IT IS ESSENTIAL THATTHE INSTRUCTIONS IN THIS MANUAL BE READ,FULLY UNDERSTOOD, AND FOLLOWED.

AVERTISSEMENT: LIRE ATTENTIVEMENT LESINSTRUCTIONS AVANT DE METTRE EN MARCHE.

Toxi Reference ManualCopyright 2004

byBiosystems LLC

651 South Main St., Middletown, Connecticut 06457

All rights reserved.No page or part of this operation manual may be reproduced in any form

without written permission of the copyright owner shown above.

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Table of ContentsIntroduction 5

Warnings and Cautions ................................................................................... 6A. Signal Words ........................................................................................... 6B. Warnings.................................................................................................. 6

Chapter 1 Toxi Description 71.1 Toxi capabilities ....................................................................................... 71.2 Methods of sampling................................................................................ 71.3 Sensor options......................................................................................... 7

1.3.1 Electrochemical toxic sensors............................................................................. 71.4 One Button Auto Calibration .................................................................... 71.5 Display backlight ...................................................................................... 81.6 Alarm logic ............................................................................................... 8

1.6.1 Atmospheric hazard alarms ................................................................................ 81.6.2 Low battery alarms.............................................................................................. 8

1.7 Special microprocessor features ............................................................. 91.8 Classification for intrinsic safety............................................................... 91.9 Options 9

1.9.1 Sensors............................................................................................................... 91.9.2 Vibrator alarm ..................................................................................................... 91.9.3 Remote sample draw assembly .......................................................................... 91.9.4 Weather cover .................................................................................................... 91.9.5 Training video ..................................................................................................... 9

1.10 Toxi design components........................................................................ 101.11 Toxi accessories .................................................................................... 10

Chapter 2 Basic operation 112.1 Overview of Toxi operation .................................................................... 11

2.1.1 Operational warnings and cautions................................................................... 112.1.2 Turning the Toxi on ........................................................................................... 112.1.3 Turning the Toxi off ........................................................................................... 112.1.4 Start-up sequence............................................................................................. 11

2.2 Operation ............................................................................................... 112.3 Toxi batteries ......................................................................................... 11

2.3.1 Low battery voltage alarms ............................................................................... 112.3.2 Battery replacement .......................................................................................... 12

2.4 Methods of sampling.............................................................................. 122.4.1 Using the hand aspirated sample draw kit ........................................................ 12

Chapter 3 Calibration 133.1 Verification of accuracy.......................................................................... 13

3.1.1 Effect of contaminants on Toxi sensors ............................................................ 143.1.1.1 Effects of contaminants on toxic gas sensors 143.1.1.2 Biosystems “CO Plus” dual purpose carbon monoxide / hydrogen sulfide sensor 14

3.1.1.2.1Relative response of the “CO Plus” sensor to CO and H2S gases 15

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3.2 Fresh air "zero" calibration..................................................................... 153.3 Functional (bump) test ........................................................................... 153.4 Auto-calibration...................................................................................... 16

3.4.1 Fresh air "zero" auto-calibration sequence....................................................... 163.4.1.1 Reading “Too High” or “Too Low” for zero adjust 16

3.4.2 “Span” auto-calibration sequence..................................................................... 173.5 Manual calibration procedure................................................................. 17

3.5.1 “Forced” fresh air "zero" through keypad buttons ............................................. 18Chapter 4 Advanced Functions 20

4.1 Setting alarm levels ............................................................................... 204.1.1 Alarm adjustment sequence.............................................................................. 204.1.2 “Alarm Latch” command .................................................................................... 214.1.3 Restoring the factory default alarm settings...................................................... 21

4.2 Re-setting the calibration gas concentration.......................................... 214.3 Setting the security beep interval........................................................... 22

Chapter 5 Trouble Shooting and Repair 235.1 Replacing Toxi sensor ........................................................................... 235.2 Troubleshooting ..................................................................................... 23

5.2.1 Unit will not turn on ........................................................................................... 245.2.2 Unit will not turn off ........................................................................................... 245.2.3 Sensor readings unstable ................................................................................. 245.2.4 Display is blank................................................................................................. 245.2.5 No audible alarm............................................................................................... 245.2.6 Keypad buttons don't work................................................................................ 245.2.7Can’t make a “One Button” auto zero adjustment (“Too High” or “Too Low” for zeroadjust)........................................................................................................................... 24

5.4 Returning your Toxi to Biosystems for service or repair ........................ 25Appendices 26

Appendix A Toxic gas measurement - Ceilings, TWAs and STELs.......... 26Appendix B How to determine where your alarms should be set .............. 27Appendix C How to calibrate your Toxi in contaminated air....................... 28Appendix D Suggested Calibration Gases................................................. 28Appendix E Cross Sensitivity Data ............................................................ 29Appendix F Toxi sensor ranges ................................................................. 29Appendix G: Biosystems Standard Warranty Gas Detection Products ........ 30

Biosystems Standard Warranty Gas Detection Products 30

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IntroductionThe Toxi is a personal, portable, microprocessor controlled, single sensor gas detector.The hazard the Toxi is designed to detect is determined by the type of sensor installedat the time of purchase. The Toxi may be configured for the detection of carbonmonoxide (CO), hydrogen sulfide (H2S), or may be equipped with a dual purpose “COPlus” sensor for the simultaneous measurement of both CO and H2S.

The Toxi uses a top-mounted LCD (liquid crystal display) to show readings of the gasbeing measured as well as other messages. An audible alarm and alarm light warnusers of hazardous conditions. An optional vibrator type alarm is also available for usein high noise or other environments requiring additional warnings. A manuallyactivated display back-light insures that the LCD may be easily read even in dim lightconditions. Biosystems’ “One Button” operating logic allows all procedures necessaryfor normal day-to-day operation, including fully automatic calibration adjustment,through use of the single on/off “Mode” button.

The Toxi is Classified by Underwriters Laboratories, Inc. and the Canadian StandardsAssociation (pending) as to Intrinsic Safety for use in Hazardous Locations Class I,Division 1, Groups A, B, C, and D. Classification for intrinsic safety is based on testsconducted in explosive gas / air (21 % Oxygen) mixtures only.

WARNING: SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY.AVERTISSEMENT: LA SUBSTITUTION DE COMPOSANTS PEUTCOMPROMETTRE LA SÉCURITÉ INTRINSÈQUE.

CAUTION: FOR SAFETY REASONS THIS EQUIPMENT MUST BE OPERATED ANDSERVICED BY QUALIFIED PERSONNEL ONLY. READ AND UNDERSTAND THEINSTRUCTION MANUAL COMPLETELY BEFORE OPERATING OR SERVICING.

ATTENTION: POUR DES RAISONS DE SÉCURITÉ, CET ÉQUIPMENT DOIT ETREUTILISÉ, ENTRETENU ET RÉPARÉ UNIQUEMENT PAR UN PERSONNEL QUALIFIÉ.ÉTUDIER LE MANUEL D'INSTRUCTIONS EN ENTIER AVANT D'UTILISER, 'ENTRETENIROU DE RÉPARER L'ÉQUIPMENT.

CAUTION: ANY RAPID UP-SCALE READING FOLLOWED BY A DECLINING OR ERRATICREADING MAY INDICATE A GAS CONCENTRATION BEYOND UPPER SCALE LIMITWHICH MAY BE HAZARDOUS.

Avertissement: Toute lecture rapide et positive, suivie d'une baisse subite au erratiquede la valeur, peut indiquer une concentration de gaz hors gamme de détection qui peutêtre dangereuse.

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Warnings and Cautions

A. Signal WordsThe following signal words, as defined by ANSI Z535.4-1998, are used in the ToxiOperator’s Guide.

indicates an imminently hazardous situation which, if not avoided, will resultin death or serious injury.

indicates a potentially hazardous situation which, if not avoided, could resultin death or serious injury.

indicates a potentially hazardous situation, which if not avoided, may resultin moderate or minor injury.

CAUTION used without the safety alert symbol indicates a potentially hazardous situationwhich, if not avoided, may result in property damage.

B. Warnings1. The Toxi personal, portable gas detector has been designed for the detection

of specific toxic gas accumulations. An alarm condition indicates the presence of a potentially life-threatening hazard and should be taken very seriously.

2. In the event of an alarm condition it is important to follow establishedprocedures. The safest course of action is to immediately leave the affected area, and to return onlyafter further testing determines that the area is once again safe for entry. Failure to immediatelyleave the area may result in serious injury or death.

3. Hand aspirated remote sampling only provides continuous gas readings aslong as the bulb is being squeezed.

4. The accuracy of Toxi instruments should be checked periodically with knownconcentration calibration gas. Failure to check accuracy can lead to inaccurate and potentiallydangerous readings.

5. A sensor that cannot be calibrated or is found to be out of tolerance must bereplaced immediately. An instrument equipped with a sensor that fails calibration may not be useduntil testing with known concentration test gas determines that accuracy has been restored, and theinstrument is once again fit for use.

6. Do not reset the calibration gas concentration setpoints in the Toxi unlessthe concentration of your calibration gas differs from the concentration of the calibration gas that isnormally supplied by Biosystems for use in calibrating the Toxi.

7. Use of non-standard calibration gas and/or calibration kit components whencalibrating the Toxi can lead to dangerously inaccurate readings and may void the standardBiosystems warranty.Biosystems offers calibration kits and long-lasting cylinders of test gas specifically developed foreasy calibration. Customers are strongly urged to use only Biosystems calibration materials whencalibrating the Toxi

8. Substitution of components may impair intrinsic safety.

9. For safety reasons the Toxi must be operated by qualified personnel only.Read, understand and follow the directions set forth in this reference manual before operating theToxi.

10. The Toxi has been tested for intrinsic safety in Explosive Gas/AIR(21.0% O2)Only.

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Chapter 1 Toxi Description1.1 Toxi capabilitiesThe Toxi single sensor gas detector canbe customized to meet specific customerrequirements. This chapter discussessome of these special features as well asbasic capabilities used on a day-to-daybasis.

1.2 Methods of samplingThe Toxi may be used as either a"Diffusion" or "Sample-Draw" typemonitoring device.In normal operation, the Toxi detector isworn on the belt, clipped into the user'sshirt pocket, suspended on the necklanyard, or held in the hand. Onceturned on, the Toxi monitorscontinuously. The atmosphere reachesthe sensor by diffusing through a dustand water-resistant protective filterdirectly into the sensor. Normal airmovements are enough to carry thesample to the sensor. The sensor reactsto changes in the concentration of thehazard being measured. Values areconstantly updated and displayed on theToxi LCD.This type of "diffusion" operationmonitors only the atmosphere thatimmediately surrounds the detector.It is possible to use a sample draw kit toobtain readings from remote locationswith a hand-operated squeeze-bulb,which is used to draw the sample inthrough a probe assembly and a lengthof hose back to the instrument. Use ofthe sample draw kit is covered insection 2.4.

1.3 Sensor optionsThe Toxi can be configured to monitorfor any one of several differentatmospheric hazards. The hazard theToxi is designed to detect is determined

by the sensor. The type of sensor mustbe specified at the time the instrument ispurchased. The types of sensorscurrently available include substance-specific electrochemical sensors for thedetection of carbon monoxide (CO) andhydrogen sulfide (H2S). In addition, adual purpose “CO Plus” sensor for thesimultaneous detection of both CO andH2S is also available for occasions whena single sensor detector must be used tomonitor for the presence of multiplehazards.Toxic gas readings are given in PPM(parts per million) concentrations.1.3.1 Electrochemical toxicsensorsThe Toxi uses highly specific,electrochemical toxic sensors that havebeen designed to minimize the effects ofcommon interfering gases. Biosystemsuses substance specific sensors toprovide accurate, dependable readingsfor carbon monoxide (CO) and hydrogensulfide (H2S). In addition to thesesubstance specific sensors, Biosystemsalso offers the “CO Plus” electrochemicalsensor. The CO Plus sensor is a dualpurpose sensor designed tosimultaneously respond to both to COand H2S.Contact Biosystems for additionalinformation concerning theappropriateness of the “CO Plus”sensor for specific applications.

1.4 One Button AutoCalibrationThe Toxi detector has been designed foreasy verification of accuracy.Biosystems’ “One Button” logic meansthat all normal day-to-day operatingprocedures, including automaticcalibration adjustment, can be made withthe on/off MODE button.

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Accuracy of the Toxishould be checked periodically withknown concentration calibration gas.Failure to check accuracy can lead toinaccurate and potentially dangerousreadings.Calibration is a two step procedure. Inthe first step the Toxi is taken to an areawhere the atmosphere is fresh and a"zero" adjustment is made. The secondstep of the calibration procedure is thesensor response or "span" adjustment.In this step the toxic sensor is exposedto known concentration calibration gas.If the instrument notes there is adeviation from the expected response, itwill automatically adjust itself so that thereadings match the concentration of thegas being used.Calibration procedures are discussedin detail in Chapter 3.

1.5 Display backlightA manually activated display backlightallows the LCD to be read in dim lightconditions. Pressing the on/off MODEbutton once at any time during normaloperation causes the backlight to beactivated for 10 seconds. In the event ofa gas alarm the backlight turns onautomatically and remains on until thealarm condition clears.

1.6 Alarm logicToxi alarms are user adjustable and maybe set anywhere within the range of thesensor. When an alarm set point isexceeded a two-toned audible alarmsounds, a bright red LED alarm lightflashes, and (if equipped) the optionalvibrator type alarm is activated.Toxi alarms are normally self-resetting.When readings drop back below the pre-set alarm levels, the instrument returnsto normal operation, and the visual andaudible alarms cease.

Toxi alarms may also be set so that they"latch." With the alarms latched, oncean alarm occurs both visual and audiblealarms continue to sound even after theatmospheric hazard has cleared. Theinstrument must be manually reset tosilence the alarms.Procedures for latching Toxi alarmsare given in Chapter 4.1.6.1 Atmospheric hazardalarms

The Toxi personal,portable gas detector has beendesigned for the detection ofdangerous atmospheric conditions.An alarm condition indicates thepresence of a potentially life-threatening hazard and should betaken very seriously.

In the event of analarm condition it is important tofollow established procedures. Thesafest course of action is toimmediately leave the affected area,and to return only after further testingdetermines that the area is once againsafe for entry. Failure to immediatelyleave the area may result in seriousinjury or death.The Toxi single gas detector is equippedwith a ceiling alarm. When readingsexceed the alarm set point, the alarmswill be triggered. Toxi alarm settings areset at the factory in the mostconservative way possible.The procedures for adjusting alarmset points or restoring the factorydefault settings are given in Chapter4.1.6.2 Low battery alarmsThe Toxi uses 3 AAA alkaline batteriesfor power. A fresh set of batteries shouldprovide up to 1,500 hours of normaloperation.

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When it is time to replace the batteries a"B" will appear in the lower left handcorner of the display screen, and theaudible alarm will “beep” once perminute until the battery is replaced. Theuser should have approximately one totwo weeks of useful life remaining.Batteries should be replaced as soon aspossible after any low battery messageis displayed.See section 2.3 of this manual forbattery replacement procedures.

1.7 Special microprocessorfeaturesSeveral automatic programs preventtampering and misuse of the Toxi. Eachtime the detector is turned on, anelectronic self-test is performed. Thesensor, LED alarm light, and audiblealarm are automatically evaluated, andthe battery is monitored continuously forproper voltage.Optional setup choices include adding asecurity beep, latching the alarms,changing the concentration of the gasthat is used during Auto Calibrationadjustment, as well as changing orrestoring the factory alarm settings. Toconfigure these options, use the 4 pushbuttons on the instrument keypadunderneath the belt clip.Chapter 4 describes advancedtechnical features and setup choicesin detail.

1.8 Classification for intrinsicsafetyThe Toxi carries the following intrinsicsafety certifications for use inhazardous locationsUnderwriters Laboratories, Inc. (UL)Class I, Division 1, Groups A, B, C, &D (Temp Code T3C) and Class II,Division 1 Groups E,F,G.

Canadian Standards Association(CSA) Class I, Division 1, Groups A, B,C, & D (Temp Code T3C).CENELEC (Ineris) EEx ia IIC T4CE MarkClassification for intrinsic safety isbased on tests conducted inexplosive gas / air (21 % Oxygen)mixtures only.

1.9 Options1.9.1 SensorsToxi detectors may be configured for thedetection of carbon monoxide (CO) orhydrogen sulfide (H2S), and may also beequipped with a “CO Plus” sensor for thesimultaneous measurement of both COand H2S. The sensor selected must bespecified at the time of purchase.1.9.2 Vibrator alarmAn internally mounted vibrating alarm isoptionally available for use in high noiseor other environments requiringadditional warnings. The vibrator alarmoption must be specified at the time theinstrument is purchased.1.9.3 Remote sample drawassemblyAn optional hand aspirated (squeezebulb) sample draw kit is available for usein situations where the sample must beobtained from remote locations. Thesample draw kit consists of a sampledraw adaptor, squeeze bulb, sampleprobe assembly, spare filters, and 10feet of sample tubing.1.9.4 Weather coverAn optional leather weather cover isavailable for use in environmentallyharsh locations, or where additionalprotection is desired.1.9.5 Training videoA comprehensive 25-minute trainingvideo is available to augment andsupport the written Owner’s Manual.

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1.10 Toxi design components(1) Case: The instrument is enclosed ina durable, gasketed case constructed ofa metal plated ABS / polycarbonatematerial.(2) LCD display: A top mounted liquidcrystal display (LCD) meter allowsdisplay of readings, messages, and otherinformation. A manually activatedbacklight insures that the LCD may beeasily read even in dim light conditions.(3) Alarm light: A bright red top-mounted LED (light emitting diode) alarmlight visually warns users when an alarmlevel is exceeded.(4) Audible alarm: A loud two-tonedaudible alarm is also provided to warnusers of hazardous conditions.(5) MODE button: The on/off "Mode"button is used to turn the instrument onand off as well as control most day-to-day functions.(6) Protective cap: A protective O-ringsealed cap and moisture barrier filter areprotect the sensor from damage.(7) Sensor: The top-mounted sensormay be easily accessed for replacementor repair.(8) Bottom surface: The stainless steelbelt clip may be removed to allow accessto the 4 hidden push-buttons ("CAL","ALM", "+" and "-") used to controladvanced functions.

Bright LED alarmlight

One button controls all normalday-to-day operations includingAuto Calibration adjustment

Accurateelectrochemicalsensor

Easy to read LCDdisplay with backlight

Loud two-toneaudible alarm

Optional built-invibrator alarm forhigh noiseenvironments

Figure 1.1: Toxi external features

Belt clip

Batterycompartmentcover

Figure 1.2: Toxi bottom surface

1.11 Toxi accessoriesToxi detectors are shipped complete withsensor, set of three AAA alkalinebatteries (installed), calibration adapter,owner’s manual and quick referencecard.Optional Toxi accessories includesample draw kit, weather cover, trainingvideo, and internally mounted vibratoralarm (vibrator option must be specifiedat time of purchase).

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Chapter 2 Basic operation2.1 Overview of Toxi operationThe Toxi operates in "Text Only" mode atall times. The display will indicate “OK”unless an alarm condition exists. Duringthe alarm the indication changes from"OK" to the numerical value, and thealarms are activated/2.1.1 Operational warningsand cautionsThe full list of operational warningsand cautions are contained at thefront of this manual immediatelypreceding chapter 1.2.1.2 Turning the Toxi onThe black switch on the top of the Toxicase is called the MODE button. It isused to turn the Toxi on and off, as wellas to control most other operations of theinstrument. Press and hold the MODEbutton for one second to turn the Toxion.2.1.3 Turning the Toxi offTurn the Toxi off by pressing and holdingthe MODE button down for 3 seconds.2.1.4 Start-up sequenceAfter the detector has been turned on, itwill automatically go through anelectronic self test and start up sequencethat takes approximately twenty seconds.During the self test sequence the LCDbacklight will be activated, the visualLED alarm light will flash, the audiblealarm will sound, and (if equipped) theoptional vibrator alarm will brieflyactivate. During start-up the LCDdisplay will also show several messagesor "screens" in sequence. The firstscreen displays the software versionnumber:

(Note: The software version installedmay differ with that shown above.) The

second shows the type of sensorinstalled:

The current status screen for the gasbeing measured will then be shownalternating with the sensor identifierscreen.

↔ 2.2 OperationUnder normal operating conditions whenthe instrument is not in alarm, the Toxiwill show OK on the display alternatelywith the sensor identifier screen

↔ An alarm condition occurs when thesensor readings exceed a pre-set alarmlevel. During the alarm the indicationchanges from "OK" to the numericalvalue, the LED alarm light flashes, theaudible alarm sounds, and (if equipped)the optional vibrator alarm is activated.

↔ Toxi alarms are normally self-resetting.When readings drop back below the pre-set alarm levels, the screen reverts tothe "OK" indication, and visual andaudible alarms cease.

2.3 Toxi batteriesThe Toxi uses a set of three AAAdisposable alkaline batteries. A fresh setof batteries should power the instrumentfor up to 1,500 hours of operation.2.3.1 Low battery voltagealarmsWhen it is time to replace the batteries a"B" will appear in the lower left handcorner of the display screen, and theaudible alarm will “beep” once perminute until the batteries are replaced.Once the “B” is shown, the user should

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have approximately one to two weeks ofuseful battery life remaining.2.3.2 Battery replacementToxi batteries should be replaced assoon as possible after a low battery ("B”)message has been noticed.

The Toxi must belocated in a non-hazardous locationwhenever alkaline batteries areremoved from the instrument.Removal of the alkaline batteries fromthe instrument in a hazardous areamay impair intrinsic safety.Use the following procedure to changethe batteries.(1) Turn the instrument off.

Figure 2.2. Toxi with belt clipremoved exposing the four keypad

push-buttons(2) Remove the belt clip from the bottom

of the instrument by sliding itcompletely free of the belt clipmounts.

(3) Loosen and remove the two screwssecuring the battery compartmentcover to the instrument case. (Thescrews must be completely removedto detach the battery compartmentcover from the instrument case.)

(4) Gently remove the batterycompartment cover by sliding itbackwards then lifting it free from theinstrument case.

(5) Remove the old batteries.

(6) Make sure the battery terminals areclean.

(7) Install the new batteries. Use highquality alkaline batteries only. (Makesure that the batteries are aligned inthe correct directions, and that allbattery polarities are correct.)

(8) Replace the battery compartmentcover, screws, and belt clip.

(9) Accuracy of the Toxi detector mustbe verified by exposure to knownconcentration test gas before theinstrument is put back into service.

2.4 Methods of samplingThe Toxi may be used as either a"Diffusion" or "Sample-Draw" typemonitoring device.In normal operation, the Toxi detector isworn on the belt, clipped into a shirtpocket, suspended from the necklanyard, or held by hand. Once turnedon, the Toxi monitors continuously. Theatmosphere being measured gets to thesensor by diffusing through a protectivemoisture barrier filter. Normal airmovements are enough to carry thesample to the sensor.The sensor reacts to changes in theconcentration of the gas beingmeasured. Values are quickly updatedand displayed on the LCD meter. Thistype of "diffusion" operation monitorsonly the atmosphere that immediatelysurrounds the detector.It is possible to use the Toxi to sampleremote locations by using a sample drawkit. The Toxi kit uses hand-aspiratedsqueeze bulb to draw a sample-back tothe instrument through a hose and probeassembly.2.4.1 Using the handaspirated sample draw kit(1) Connect the slip-on sample draw cup

to the squeeze bulb and hoseassembly. Connect the end of the

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short length of hose closest to thebulb to the sample draw cup. Connectthe other end of the hose to thesample probe.

(2) To test the seals in the sample drawsystem, cover the end of the sampledraw probe with a finger, and squeezethe aspirator bulb. If there are noleaks in the sample draw kitcomponents, the bulb should staydeflated for a few seconds.

(3) Slide the sample draw adapter (withthe sample draw assembly) over thesensor cover on the Toxi.

(4) Insert the end of the sample probeinto the location to be sampled.

(5) To ensure accurate readings whileusing the manual sample draw kit, it isnecessary to squeeze the bulb oncefor every one foot of sampling hose forthe sample to first reach the sensors,and then to continue squeezing thebulb once per second for an additional45 seconds or until readings stabilize.

Caution: Hand aspirated remotesampling only provides continuousgas readings as long as the bulb isbeing squeezed.Each time a reading is desired, it isnecessary to squeeze the bulb asufficient number of times to bring afresh sample to the sensor.

Chapter 3 CalibrationThe Toxi detector has been designed foreasy calibration. The MODE button isused to enter the “Auto-Calibration”mode, and automatically make allcalibration adjustments. It is alsopossible to manually calibrate theinstrument by using simple push-buttoncontrols located on the instrumentkeypad.“One-Button Auto-Cal” proceduresare discussed in Section 3.4. Manualcalibration procedures are discussedin Section 3.5.

3.1 Verification of accuracy The accuracy of

Toxi instruments should be checkedperiodically with known concentrationcalibration gas. Failure to checkaccuracy can lead to inaccurate andpotentially dangerous readings.Verification of accuracy is a two stepprocedure. In the first step the Toxi istaken to an area where the atmosphereis fresh and the readings are checked. Ifthe readings differ from those expectedin fresh air a "zero" adjustment must bemade. The second step is to make surethe sensor is accurate by exposing it toknown concentration test gas and notingthe response. Readings are consideredaccurate when they are within ±10% ofthe expected concentration as given onthe calibration gas cylinder. If readingsare accurate, there is no need to adjustyour gas detector. If the readings areinaccurate, the instrument must be spancalibrated before further use.Biosystems offers calibration kits andlong lasting cylinders of test gasspecifically developed for easy Toxicalibration. Customers are urged to useBiosystems calibration materials whencalibrating their Toxi detectors.

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Use of non-standard calibration gas and/orcalibration kit components whencalibrating the Toxi can lead todangerously inaccurate readings andmay void the standard Biosystemswarranty.3.1.1 Effect of contaminantson Toxi sensorsThe atmosphere in which the Toximonitor is being used can have an effecton the sensor. Sensors may bepoisoned or suffer degradedperformance if exposed to certainsubstances.

The accuracy ofthe Toxi should be checkedimmediately following any knownexposure to contaminants by testingwith known concentration test gasbefore further use.3.1.1.1 Effects of contaminants ontoxic gas sensorsBiosystems “substance-specific”electrochemical used to measure CO,and H2S have been carefully designed tominimize the effects of commoninterfering gases. “Substance-specific”sensors are designed to respond only tothe gas that they are supposed tomeasure. The higher the specificity ofthe sensor the less likely the sensor willbe affected by exposure to other gaseswhich may be incidentally present. Forinstance, a “substance-specific” carbonmonoxide sensor is deliberatelydesigned not to respond to other gasesthat may be present at the same time,such as hydrogen sulfide and methane.Although great care has been taken toreduce cross-sensitivity, some interferinggases may still have an effect on toxicsensor readings. In some cases theinterfering effect may be positive andresult in readings that are higher thanactual. In other cases the interference

may be negative and produce readingsthat are lower than actual or even resultin negative gas readings.Cross sensitivity of Toxi toxic sensorsto common interfering gases is listedin Appendix E.3.1.1.2 Biosystems “CO Plus” dualpurpose carbon monoxide / hydrogensulfide sensorCarbon monoxide and hydrogen sulfideare the two most widely occurring toxicgases found in the industrial workplace.In addition to “substance specific”sensors designed to measure these toxichazards, Biosystems also offers a dualpurpose sensor designed tosimultaneously detect both carbonmonoxide and hydrogen sulfide. The“CO Plus” sensor is ideal for situationsrequiring use of a single sensor tomonitor simultaneously for both toxichazards.The “CO Plus” sensor has beendesigned to respond to both carbonmonoxide and hydrogen sulfide, and canbe calibrated for the direct detection ofeither hazard. Since the sensor hasbeen designed to respond to bothhazards at once, it cannot discriminatebetween or tell which of the two gases isproducing the reading. The sensor can’ttell which hazard is present in whatspecific concentrations, but it will go intoalarm if readings exceed the instrument’salarm level for a CO or H2S hazard.Note: When a specific contaminantsuch as hydrogen sulfide is known tobe potentially present the bestapproach is usually to use a directreading substance specific sensor. Ifhydrogen sulfide is known to bepotentially present, the sensorselected should be specifically for thedetection of H2S, and calibrateddirectly to this hazard.

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Calibration of the COPlus sensor with multi-componentcalibration gas mixtures containingboth CO and H2S may lead toinaccurate and potentially dangerousreadings.Biosystems “CO Plus” sensors aredesigned for the simultaneous detectionof both carbon monoxide and hydrogensulfide. The calibration gas used tocalibrate “CO Plus” sensors may containonly one of these two gases. If a “COPlus” sensor is calibrated with a mixturethat contains both carbon monoxide andhydrogen sulfide readings may bedangerously low.Biosystems multi-component calibrationgas mixtures which contain both carbonmonoxide and hydrogen sulfide arelabeled as “Not for use with CO Plussensors”.Note: “CO Plus” sensors are normallycalibrated to carbon monoxide. Thecalibration gas normally usedcontains a mixture of 50 PPM CO.3.1.1.2.1 Relative response of the “COPlus” sensor to CO and H2S gasesA “CO Plus” sensor which has beenproperly calibrated to carbon monoxidewill be exactly accurate for the substanceto which it was calibrated. OSHA (1989)permissible exposure limits for carbonmonoxide specify an 8 hour TWA limit of35 PPM. If the “CO Plus” sensor iscalibrated to carbon monoxide thenexposed to 35 PPM carbon monoxide thereading will be 35 PPM.The “CO Plus” sensor will also show a“relative response” to other interferinggases. When calibrated on carbonmonoxide the relative response of the“CO Plus” sensor to hydrogen sulfide is aratio of about 3.5 to 1.0. This means aconcentration of about 10 PPM hydrogensulfide would produce a “CO+” sensorreading of 10 X 3.5 or 35 PPM.

This is a very convenient relativeresponse. The 8 hour TWA permissibleexposure limit for hydrogen sulfide is 10PPM. This means that the “CO+” gasalarms will be tripped any time theconcentration of hydrogen sulfideexceeds the permissible exposure limit.Note: Cross sensitivity of the “COPlus” sensor to carbon monoxide,hydrogen sulfide and other commoninterfering gases is listed in AppendixE.

3.2 Fresh air "zero" calibrationThe fresh air "zero" must be done infresh, uncontaminated air. In thisprocedure the instrument automaticallyadjusts its readings to match theconcentrations present in fresh air.Fresh air contains 0 PPM toxic gas.If the Toxi cannot be taken to an areawhere the air is fresh, or if it is not certainwhether or not the air is uncontaminated,special procedures are required. Theseprocedures are discussed at greaterlength in Appendix C.The second step is to verify the accuracyof the sensor by exposing it to knownconcentration test gas.

3.3 Functional (bump) testA simple functional (bump) test is all thatis needed to verify accuracy.To perform a functional (bump) test, turnthe Toxi on, and wait at least threeminutes to allow the readings to fullystabilize. Wait at least 15 minutes if thesensor has just been replaced. Makesure the instrument is located in fresh air.Check to see that the readings match theconcentrations present in fresh air. Thedisplay should indicate “OK”. Ifnecessary, fresh air zero the instrumentusing the procedures discussed inSection 3.4.1.

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Slip on the calibration adapter asdiscussed in Section 3.4.2, and flowcalibration gas to the sensor. Wait forthe readings to stabilize. (Forty-fiveseconds to one minute is usuallysufficient.) Note the readings. Readingsare considered accurate when they arewithin ±10% of the expectedconcentration as given on the calibrationgas cylinder. If readings are accurate,there is no need to adjust your gasdetector. If the readings are inaccurate,the instrument must be span calibratedbefore further use.

3.4 Auto-calibrationBiosystems “One-Button Auto-Calibration” mode may be used to verifyaccuracy any time during normalinstrument operation.Press the MODE button 3 times in rapidsequence to place the instrument in the“Auto-Calibration” mode. Once in theAuto Calibration mode the adjustmentsare made automatically.Auto-calibration is a two step procedure.In the first step the Toxi is taken to anarea where the atmosphere is fresh anda "zero" adjustment is madeautomatically by pressing the on / offMODE button. The second step is thesensor response or "span" calibrationadjustment. In this step the accuracy ofthe Toxi sensor is established byexposing it to known concentrationcalibration gas.3.4.1 Fresh air "zero" auto-calibration sequence(1) Turn the instrument on and wait at

least three minutes to allow sensorreadings to stabilize fully beforeinitiating auto-calibration procedures.Wait at least 15 minutes if the sensorhas just been replaced.

(2) Make sure the instrument is locatedin an area where the air is known tobe fresh.

(3) Press the MODE button 3 timeswithin two seconds. This will "wakeup" the instrument from normaloperation, and put it into the “Auto-Calibration” mode.A screen will briefly display themessage “ZERO MODE”.

→ (4) Press the MODE button within five

seconds to initiate the fresh airadjustment. (If the MODE button isnot pushed within 5 seconds, theinstrument will return to normaloperation.)The screen will show the message“WAIT ZERO” while the adjustment isbeing completed.

↔ (5) Following successful completion of

the “zero” auto-calibration, the displaywill prompt you with the message“SPAN MODE” to continue with aspan calibration adjustment.

3.4.1.1 Reading “Too High” or “TooLow” for zero adjustTo reduce the chances of the Toxi beinginadvertently zeroed in contaminated air,only small adjustments are allowedthrough the use of the “One Button”auto-zero sequence. If the necessaryadjustments are too large the display willindicate that the reading is too low or toohigh for zero adjustment. In this case theinstrument must be fresh air zeroedusing the “Cal” button on the instrumentkeypad and procedures discussed inSection 3.5.1 of this manual.Once the instrument has beensuccessfully zeroed using the “Cal”button, subsequent calibrationadjustments may be made using the

17

MODE button and “One Button Auto Cal”logic discussed in this section.3.4.2 “Span” auto-calibrationsequenceAfter successful completion of the “zero”auto-calibration adjustment the displaywill show the message “SPAN MODE”.

↔ If the MODE button is not pushed withinfive seconds a span calibrationadjustment will not be made, and theinstrument will be returned to normaloperation.(1) Press the MODE button within 5

seconds to initiate “span” auto-calibration. A screen will ask you to“FLOW GAS”. The instrument willcontinue to display this screen until itdetermines that calibration gas hasbeen applied.

↔ Note: It is possible to exit the auto-calibration mode at any time prior tocompletion by pressing and holdingdown the MODE button for 3 secondsto turn the instrument off.(2) Attach the cylinder of calibration gas,

regulator, short section of tubing andcalibration adapter to the Toxi.

Make sure theregulator, cylinder seating surfacesand threads are clean and dry beforeattaching the regulator to the cylinderof gas. Introduction of contaminantsthrough the regulator fittings mayalter or degrade the concentration ofthe gas contained in the cylinder andmay lead to inaccurate and potentiallydangerous gas readings.

The regulator will automatically beginflowing calibration gas as soon as it isscrewed into the cylinder of gas.

(3) The instrument will display thesensor readings as they rise. Whenthey have stabilized at their highestvalue, the instrument will note theresponse and, if necessary, adjust thereadings to match the concentration ofgas being used to calibrate thedetector. (The instrument will beep asthe adjustment is being made.)

Calibration valuesshown on the “Span Adjust” screenas the sensor is adjusted must matchthose appearing on the calibrationgas cylinder(s) that will be used tocalibrate the Toxi. Non-matchingcalibration gas and calibration gasvalue settings will lead to inaccurateand potentially dangerous readings.If the concentration does not match itwill be necessary to assign a newcalibration gas concentration asdiscussed in Chapter 4 beforecontinuing with the auto-spanadjustment.(4) When span adjustment has been

completed, the display will show themessage “DONE”, after which theinstrument will return to the gasindicator mode, and display thecurrent gas readings.

Note: Make sure the calibrationadapter and all other fittings havebeen removed from the detectorbefore it is returned to service.

3.5 Manual calibrationprocedureIt is also possible to calibrate the Toximanually using the four buttons on theinstrument keypad.

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3.5.1 “Forced” fresh air"zero" through keypadbuttons

Only perform the“forced” fresh air calibration in anatmosphere that is known to be freeof toxic gases. Performing a “forced”fresh air calibration in a contaminatedatmosphere will lead to inaccurateand potentially dangerous readings.(1) Turn the instrument on.(2) Wait at least three minutes after

turning the instrument on to allowsensor readings to stabilize fullybefore initiating the fresh air zeroprocedure. Wait at least 15 minutes ifthe sensor has just been replaced.

(3) Slide the belt clip towards the rear ofthe instrument exposing the fourbuttons on the instrument keypad.

(4) Make sure the instrument is locatedin an area where the air is known tobe fresh.

(5) Press the keypad button marked"Cal". The “GAS ZERO” calibrationmessage will appear on the instrumentLCD.

↔ (6) Press “Cal” to automatically zero the

instrument. The LCD will show themessage “ZERO WAIT” while theadjustment is being made.

↔ (7) After completion of the zero

adjustment the Toxi automaticallyreturns to the gas reading screendisplay.

(8) Pressing the MODE button causesthe calibration values in the memoryto remain unchanged from the lasttime a fresh air adjustment was made.An information screen is displayed

briefly which verifies that the zerovalues have not been changed. Theinstrument will then return to normaloperation.

↔ 3.5.2 Span calibration using keypadbuttonsSpan calibration procedures usingbuttons on the instrument keypad areonly necessary when the adjustmentnecessary to restore accuracy is outsidethe permissible window of adjustment for(1) Turn the instrument on and wait at

least three minutes to allow sensorreadings to stabilize fully beforeinitiating the fresh air zero procedure.Wait at least 15 minutes if the sensorhas just been replaced.

(2) Remove the belt clip by sliding it freefrom the belt clip mounts to exposethe four mini-push-buttons.

(3) Turn the instrument off by pressingthe MODE button for three fullseconds.

(4) With the unit turned off, press andhold down the "Cal" button.

(5) While holding down the "Cal" button,press the MODE button to turn the Toxiback on. A screen showing the message“SPAN” will alternate with the sensorreadings.

↔ To cancel the calibration press andhold the MODE button for threeseconds.

(7) Attach the cylinder of gas, regulator,short section of tubing and calibrationadaptor to the Toxi. Make sure theregulator, cylinder seating surfaces,and threads are clean and dry.

(8) The regulator will automaticallybegin flowing gas at the correct flowrate as soon as it is fully screwed in.Readings typically stabilize in 45-60

19

seconds. When the readings stabilizeuse the "+" and "-" keys to raise orlower the readings to match theconcentration printed on thecalibration cylinder label.

(9) Make sure the correct cylinder of gasis attached before attempting to adjustthe span! If the concentration of gasreaching the sensor is too low to allowthe instrument to be adjusted, or if thewrong type of gas is applied to thesensor being adjusted, the alarms willbe activated and a screen will bedisplayed indicating that theinstrument “CANT / SPAN”. Pressingthe MODE button clears the “CANTSPAN” message and returns theinstrument to normal operation.

↔ In the event that a “CANT SPAN”message is displayed, verify the typeand concentration of the gas beingused is correct for the sensor beingcalibrated. The expiration date of thecylinder should also be checked.Replace the cylinder if necessary.Verify that the flow rate of theregulator is 1.0 liters per minute. Ifthe "CANT SPAN" message isrepeated it may indicate that thesensor is unresponsive, or dead, andrequires replacement.

(10) When span calibration has beencompleted, press and hold the "Cal"button down until the LCD screenindicates that calibration is completeby showing the message “DONE”.The Toxi will then turn itself off.

Caution: The “Cal” button must beheld down until the screen indicatesthat span calibration has beensuccessfully completed.If the button is released before thismessage is displayed, span values will

not be updated, and remain unchangedfrom the last time a span calibration wassuccessfully completed.Pressing the MODE button at any timecancels the manual span calibrationprocedure. A screen will announce “NOSAVE” after which the instrument willturn itself off.

↔ A sensor that

cannot be calibrated or is found to beout of tolerance must be replacedimmediately. An instrument equippedthat fails calibration may not be useduntil testing with known concentrationtest gas determines that accuracy hasbeen restored, and the instrument isonce again fit for use.Pressing the MODE button at any timeduring the span adjustment cancels theprocedure, and causes the calibrationvalues in memory to remain unchangedfrom the last time a span calibrationadjustment was made.

Chapter 4 AdvancedFunctionsThe Toxi microprocessor circuitry makes anumber of advanced features andcapabilities possible. Although this chapterhas been designed primarily to be ofbenefit to "experts" there are severalsections that may be of interest to all Toxiusers.The keypad consists of four mini pushbuttons that are located under the beltclipon the bottom of the detector. Thetechnique for making advanced setupchanges requires several buttons to bepressed at the same time.

Pressingcombinations of buttons not explicitlycovered in this section may result inunintended changes to the instrumentsetup.

4.1 Setting alarm levelsToxi alarms are user adjustable and maybe set anywhere within the range of thesensor channel. When an alarm set pointis exceeded a loud audible alarm sounds,the bright red LED alarm light blinks, and (ifequipped) the optional vibrator alarm isactivated.Toxi alarms are normally self-resetting.When readings drop back below the pre-set alarm levels, visual and audible alarmscease, and normal operation of theinstrument resumes. It is possible to setToxi alarms so that they "latch." In thelatched condition, once an alarm occursboth visual and audible alarms continue tosound even after the atmospheric hazardhas cleared. Press the MODE button toreset the instrument, silence the alarmsand restore normal operation. Proceduresfor latching Toxi alarms are given inSection 4.2.

4.1.1 Alarm adjustmentsequenceTo change alarm settings, the instrumentmust be placed in the "Alarm Adjust" mode.Once in this mode, alarm set points may beadjusted.In many cases it is possible to comply withOSHA guidelines while using higher alarmpoints than those used by Biosystems. It isimportant to note that the default alarmpoint settings used in the Toxi design arevery conservative in order to providemaximum worker safety.Toxi default alarm setting are listed inAppendix B.To enter the alarm adjust mode:(1) Turn the instrument on.(2) Remove the belt clip to expose the

four mini-push-buttons.(3) Turn the instrument off by pressing

and holding the MODE button for threefull seconds.

(4) With the unit turned off, press and holddown the "Alarm" button, then pressthe MODE button to turn the Toxi backon.

(5) A screen will appear showing the firstalarm point to be adjusted, and thecurrent alarm set point.

→ →

(6) Use the "+" and "-" keys to raise orlower the alarm setpoint. Press theMODE button at any time to cancel thealarm adjustment and return theinstrument to the gas readings screen.

(7) When all alarm adjustment has beencompleted, press and hold the "Alarm"button down until an informationscreen indicates that alarm adjustmentis complete.

The instrument will display the “ALRMLOCK” screen used to latch or lock Toxialarms as discussed in Section 4.1.2.

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Press the MODE button again to turn theToxi detector off.4.1.2 “Alarm Latch” commandToxi alarms are normally self-resetting.When readings drop back below the pre-set alarm levels, visual and audible alarmscease, and normal operation of theinstrument resumes. It is possible to setToxi alarms so that they "latch." In thelatched condition, once an alarm occursboth visual and audible alarms continue tosound even after the atmospheric hazardhas cleared. Press the MODE button toreset the instrument, silence the alarmsand restore normal operation.Use the following procedure to “latch” theToxi alarms:(1) Turn the instrument on while pressing

and holding down the “Alarm” button.This will place the instrument in the“Alarm Adjust Mode”.

(2) Adjust and save the current alarmsettings, or press mode to exit withoutmaking changes to the current settings.As the instrument leaves the “AlarmAdjust Mode” the unit will displayalternating “ALRM / LOCK” messagesfor 4 seconds. The instrument will thendisplay the current status of the alarmlatch feature (“ON” or “OFF”).

(3) Use the “+” or “-” key to change thealarm latch setting. LOCK ONindicates that the alarm will be latchedwhenever it is activated. Once theatmospheric hazard has cleared, theuser will need to acknowledge thealarm by pressing the MODE button.

(4) Once the proper setting has beenselected, press and hold down the“ALM” button for three seconds. Do notrelease the “ALM” button until the LCDdisplays the message “DONE” toindicate that the new setting has beensuccessfully entered.Press the MODE button at any time tocancel the procedure. The LCD will

show the message “NO SAVE” toindicate that the setting has not beenchanged.

4.1.3 Restoring the factorydefault alarm settingsToxi alarm settings are set at the factory inthe most conservative way possible. (SeeAppendix B) It is possible to restore thesedefault settings at any time by doing thefollowing.(1) Turn the instrument on.(2) Press the "ALM" button on the

instrument key-pad. The display willbriefly show the default alarmmessage, and the type of sensorcurrently installed.

→ →(3) The default alarm setting will then be

shown. In the case of a Toxi with ahydrogen sulfide sensor installed, thefollowing screens will alternate.

↔ (5) Push and hold the "ALM" button to

restore the factory default alarmsettings. The display indicates whenthe settings have been restored andthen returns to the current gas readingsscreen.

(6) Press the “CAL” button to keep thecurrent alarm settings. The display willshow “NO SAVE” before it returns tothe current gas readings screen.

↔

4.2 Re-setting the calibration gasconcentrationDuring calibration the Toxi adjusts thesensitivity of the sensor to match theconcentration of the gas used to calibratethe sensor. The value the instrument usesto adjust the reading is the calibration gas

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concentration stored in the instrumentmemory.For instance, Biosystems normally suppliescalibration gas containing 50 PPM carbonmonoxide for use in calibrating CO Toxidetectors. This is the default calibrationgas concentration stored in the instrumentmemory. When gas is applied to thesensor during auto calibration, theinstrument automatically adjusts thesensitivity of the carbon monoxide toproduce readings that match this 50 PPMconcentration.

Sensor Gas Used Concentration

CO CO 50 PPMCO+ CO 50 PPMH2S H2S 25 PPM

Table 5.1. Default Toxi calibration gasconcentrations

It is necessary to reset the calibration gasconcentration stored in instrument memorybefore making use of a different calibrationgas concentration.

Do not reset thecalibration gas concentration unless youare using a calibration gasconcentration that differs from thatnormally supplied by Biosystems foruse in calibrating your instrument.Customers are strongly urged to useonly Biosystems calibration materialswhen calibrating their Toxi detector.Use of non-standard calibration gasand/or calibration kit components canlead to dangerously inaccurate readingsand may void the standard Biosystemswarranty.Use the following procedure to re-set thecalibration gas concentration:(1) Turn the instrument on while pressing

and holding down the “+” button.The Toxi LCD will display alternating“CAL” and “GAS” messages for 4seconds. The display will thenalternate between the current

concentration stored in memory and the“GAS” message screens.

(2) Use the “+” and “-” buttons to changethe concentration.

(3) Once the proper new concentration hasbeen selected, press and hold downthe “ALM” button for three seconds tosave the new setting. Do not releasethe “ALM” button until the LCD displaysthe message “DONE” to indicate thatthe new value has been successfullyentered.

(4) To cancel the changes, press and holdthe MODE button. The LCD will showthe message “NO SAVE” to indicatethat the calibration gas concentrationvalues have not been changed.

4.3 Setting the security beepintervalThe security beep screen allows the Toxi tobe programmed to emit an audible alarm"beep" on a regular basis while theinstrument is in operation. This periodicbeep serves as a reminder that theinstrument is on.Use the following procedure to turn thesecurity beep on:(1) Turn the instrument on while pressing

and holding down the “-” button.(2) The Toxi LCD will display alternating

“SEC” and “BEEP” messages for 4seconds. The display will thenalternate between the current securitybeep interval in minutes and themessage “MIN”.

(3) Use the “+” and “-” buttons to set thesecurity beep interval (the timebetween beeps).

The interval may be set in increments ofone minute anywhere between 0 and 60minutes. Set the interval to 0 to turn thesecurity beep off.

(4) Once the proper setting has beenselected, press and hold down the“ALM” button for three seconds. Do not

23

release the “ALM” button until the LCDdisplays the message “DONE” toindicate that the new setting has beensuccessfully entered.Pressing the MODE button at any timecancels the procedure. The LCD willshow the message “NO SAVE” toindicate that the setting has not beenchanged.

Chapter 5 Trouble Shootingand Repair5.1 Replacing Toxi sensor

The Toxi must berecalibrated before being returned toservice any time the sensor is removedor replaced.To replace a sensor:(1) Make sure the Toxi is turned off.(2) Gently unscrew (1/4 turn counter

clockwise) and remove the protectivesensor cap.

(3) Gently pry the sensor out of its socket.(4) Verify that the type of sensor to be

installed matches the label on thefront of the Toxi detector.

(5) Make sure the pins are properlyaligned and gently press thereplacement sensor into place.

(6) Make sure the correct color codedfilter in the protective sensor cap isreplaced along with the new sensor.(A spare filter should have beensupplied together with thereplacement sensor.) The color of thefilter should match the color of the IDring on the upper surface of thesensor. Use a blunt object to pushthe old filter out of the sensor cap,and using a finger, press the new filterinto place. Be careful not to rip thefilter membrane.

(7) Replace the protective sensor cap.(8) Allow at least 15 minutes for the

sensor to stabilize.(9) Recalibrate the new sensor.

5.2 TroubleshootingThere are a few troubleshooting and repairprocedures that can be done in the field.Caution: The following repairprocedures should only be performed byauthorized personnel.

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5.2.1 Unit will not turn onPossible causes:Battery discharged, microprocessor /software malfunction.Solution(s):Take the instrument to a non-hazardouslocation. Replace the batteries andattempt to turn on. (Make sure that thebatteries are properly aligned, and thatall battery polarities are correct.) If theinstrument still fails to turn on, return tofactory for repair.

5.2.2 Unit will not turn offPossible causes:Microprocessor / software malfunction,low or bad battery, faulty on / off modeswitch.Solution(s):Take the instrument to a non-hazardouslocation, replace the batteries, andattempt to turn the detector back on. Ifthe instrument fails to turn on, return tofactory for repair.

5.2.3 Sensor readings unstablePossible causes:Loose connection, bad sensor, impropercalibration, expired calibration gas.Solution(s):Check that the sensor is firmly in place.Check calibration gas dating. Re-calibrate sensor. Replace sensor ifnecessary.

5.2.4 Display is blankPossible causes:Battery voltage too low. Operatingtemperature too low. Bad LCD displayassembly. Microprocessor locked-up or"crashed".Solution(s):Take the instrument to a non-hazardouslocation. If cold, allow instrument towarm back up to room temperature.Replace the batteries and attempt to

turn the instrument back on. If theinstrument still fails to turn on, return tofactory for repair.

5.2.5 No audible alarmPossible causes:Loose connection, alarm failure.Solution(s):Return to factory for repair.

5.2.6 Keypad buttons don'twork

Possible causes:Microprocessor locked-up or "crashed",loose connection, switch failure.Solution(s)Take the instrument to a non-hazardouslocation. Replace the batteries andattempt to turn the instrument back on.If keypad buttons still fail to operateproperly return to factory for repair.

5.2.7 Can’t make a “OneButton” auto zero adjustment(“Too High” or “Too Low” forzero adjust)

Possible causes:The atmosphere in which the instrumentis located is contaminated (or wascontaminated at the time the instrumentwas last zeroed); instrument is stillattached to calibration fittings; a newsensor has just been installed;instrument has been dropped or bangedsince last turned on.Solution(s):Remove any calibration gas fittings,take the instrument to fresh air andallow readings to stabilize. Do amanual fresh air zero adjustment usingbuttons on the instrument keypad asdiscussed in Section 3.5.1.

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5.4 Returning your Toxi toBiosystems for service orrepair

Please contact the Biosystems ServiceDepartment at (860) 344-1079 to obtain a“Return Authorization” number prior toshipment. A Biosystems Servicerepresentative will record all relevantinformation or special instructions at thattime.To insure safe transport please use theoriginal Toxi packing materials, or otherpacking materials which similarly protectthe instrument and accessories.Note: The return authorization numbermust be clearly marked on the outside ofthe box.Prominently showing the returnauthorization number on the outside of thebox ensures that it is immediately identifiedand logged into our system at the time it isreceived. Proper tracking helps avoidunnecessary delays in completion ofservice procedures.Please contact the Biosystems ServiceDepartment at (860) 344-1079 or 800 711-6776 if you require any additionalinformation.

Thank you for choosingthe Toxi, and thank you

for choosing Biosystems.

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AppendicesAppendix A Toxic gasmeasurement - Ceilings, TWAs andSTELsMany toxic substances are commonlyencountered in industry. The presence oftoxic substances may be due to materialsbeing stored or used, the work beingperformed, or may be generated by naturalprocesses. Exposure to toxic substances canproduce disease, bodily injury, or death inunprotected workers.It is important to determine the amounts ofany toxic materials potentially present in theworkplace. The amounts of toxic materialspotentially present will affect the proceduresand personal protective equipment whichmust be used. The safest course of action isto eliminate or permanently control hazardsthrough engineering, workplace controls,ventilation, or other safety procedures.Unprotected workers may not be exposed tolevels of toxic contaminants which exceedPermissible Exposure Limit (PEL)concentrations. Ongoing monitoring isnecessary to insure that exposure levelshave not changed in a way that requires theuse of different or more rigorous proceduresor equipment.Airborne toxic substances are typicallyclassified on the basis of their ability toproduce physiological effects on exposedworkers. Toxic substances tend to producesymptoms in two time frames.Higher levels of exposure tend to produceimmediate (acute) effects, while lower levelsof long-term (chronic) exposure may notproduce physiological symptoms for years.Hydrogen sulfide (H2S) is a good example ofan acutely toxic substance which isimmediately lethal at relatively lowconcentrations. Exposure to a 1,000 ppm(parts per million) concentration of H2S in airproduces rapid paralysis of the respiratorysystem, cardiac arrest, and death withinminutes.

Carbon monoxide (CO) is a good example ofa chronically toxic gas. Carbon monoxidebonds to the hemoglobin molecules in redblood cells. Red blood cells contaminatedwith CO are unable to transport oxygen.Although very high concentrations of carbonmonoxide may be acutely toxic, and lead toimmediate respiratory arrest or death, it is thelong term physiological effects due to chronicexposure at lower levels that take thegreatest toll of affected workers. This is thesituation with regards to smokers, parkinggarage attendants, or others chronicallyexposed to carbon monoxide in theworkplace. Exposure levels are too low toproduce immediate symptoms, but smallrepeated doses reduce the oxygen carryingcapacity of the blood over time todangerously lowlevels. This partial impairment of the bloodsupply may lead over time to seriousphysiological consequences.1. Ceiling level:OSHA has assigned some, but not all, toxicsubstances with a ceiling level. This is thehighest concentration of a toxic substance towhich an unprotected worker should ever beexposed, even for a very short time. Neverenter an environment even momentarilywhen concentrations of toxic substancesexceed the ceiling level.

Time History Graph

Ceiling

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Appendix B How to determinewhere your alarms should be set1. Toxic gas alarmsThe Toxi has a ceiling alarm point for toxicgases.OSHA has assigned some, but not all, toxicsubstances with a ceiling or "Peak"exposure level. This is the highestconcentration of a toxic substance to whichan unprotected worker should ever beexposed, even for a very short time. Neverenter an environment even momentarilywhen concentrations of toxic substancesexceed the ceiling level.The table below shows the highest levels atwhich these alarms should be set. If OSHAhas not determined a ceiling value, forgreatest safety the Toxi ceiling alarmshould be set at the same value as theSTEL alarm. If OSHA has not determined aSTEL value, the Toxi STEL alarm shouldbe set at the same value as the TWA.2. U. S. Department of Labor,Occupational Safety and HealthAdministration (OSHA) PermissibleExposure Limits for select toxic gases:In the following table "NA" indicates novalue has been assigned by OSHA.Note: Customers should be aware thatOSHA permissible exposure limits maybe subject to change.Recent court decisions have affectedthe enforcement of permissibleexposure limits published or modifiedsince the initial enactment of OSHA in1971. The following table shows theOSHA permissible exposure limits aspublished in the 1989 edition of theCode of Federal Regulations (29 CFR1910.1000). It is recommended thatcustomers verify that the values givenbelow are correct and current beforeusing them to update their alarm set-points.

OSHA (1989) Permissible Exposure Limits:Gas Ceiling TWA STELCO 200 PPM 35 PPM NAH2S NA 10 PPM 15 PPM

3. Toxi default alarm settingsThe most conservative possible way to setalarms is the method used by Biosystemsfor the Toxi default alarm settings. TheCeiling alarm is set at the factoryat the 8 hour TWA level (when this isgiven). With this setting, it is unlikely thateither the STEL or TWA alarm will ever beactivated. For other values, contactBiosystems or your authorized distributor.

Biosystems Toxi default alarm settings:Gas Ceiling

CO 35 PPMH2S 10 PPM

Note: When a “CO Plus” sensor isinstalled the default alarm settings areautomatically assigned on the basis ofthe calibration gas selected for use. Ifcarbon monoxide is selected as thecalibration gas, carbon monoxide alarmsettings are automatically assigned. Ifhydrogen sulfide is selected as thecalibration gas, hydrogen sulfide alarmsettings are automatically assigned.

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Appendix C How to calibrate yourToxi in contaminated airCalibration of the Toxi is a two-stepprocess. The first step is to expose thesensors to contaminate-free fresh air andperform a fresh air calibration.Unfortunately, there are some locationsthat are never completely free ofcontaminants. An example would be afurnace intensive area that always has abackground concentration of a few PPMCO. To make calibration easy in this case,it is necessary to use special calibration"Zero Contaminant" gas. This gas cylinder,Biosystems part number 9039, is used inconjunction with the sample drawcalibration adapter. Flow the zerocontaminant gas across the sensors for aminute, just as if you were doing a spancalibration. Then do the fresh aircalibration steps described in Chapter 3 ofthe owners manual.

Appendix D SuggestedCalibration GasesWarning: Use of non-standardcalibration gas and / or calibration kitcomponents when calibrating your Toxican lead to dangerously inaccuratereadings and may void the standardBiosystems warranty.Biosystems offers calibration kits andlong lasting cylinders of test gasspecifically developed for easy Toxicalibration. Customers are stronglyurged to use only Biosystemscalibration materials when calibratingtheir Toxi.

PartNumber

Calibration gasmixture

Comments

54-9033 Carbonmonoxide (CO)(50 PPM in air)

54-9034 Hydrogen sulfide(H2S) (25 PPMin nitrogen)

54-9039 Zero air (20.9 %oxygen innitrogen)

Use for fresh aircalibration incontaminated areas.

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Appendix E Cross SensitivityData1

The table below lists the cross sensitivity ofelectrochemical toxic sensors used in theToxi portable gas detectors to gases otherthan their target gas. Depending on thenature of the reaction each gas has withthe sensor, the effect can either decreasethe signal (negative cross sensitivity) orincrease the signal; (positive crosssensitivity). Each figure represents thereaction of the sensor to 100 PPM of gas,thus providing a percentage sensitivity tothat gas relative to its target gas.

SENSOR TYPE

Carbonmonoxide(CO)

Hydrogensulfide(H2S)

CO Plus(Cal toCO)

CO Plus (Calto H2S)

CO 100 < 10 100 25H2S < 10 100 ~ 350 100SO2 < 10 ~ 20 ~ 65 ~ 15NO < 30 < 0 ~ 25 ~ 6NO2 < 15 ~ - 20 ~ - 60 - 15Cl2 < 10 ~ - 20 ~ - 40 ~ - 10H2 < 60 < 5 < 60 < 15HCN < 15 0 ~ 40 ~ 10HCl < 3 0 ~ 5 ~ 1NH3 0 0Ethylene

~ 50 0

1Data derived in part from City Technology Limited, Product DataHandbook Oct. 1, 1992

Appendix F Toxi sensor rangesThe following tables display the ranges forcurrently available sensors for use in theToxi. Nominal range values indicate thegas-level range which the Toxi can detectover extended periods of operation. “Maxoverload” values indicate the highestinstantaneous reading that the Toxi will beable to attain for a given sensor type.

Toxic SensorType

Nominalrange (PPM)

Maxoverload

CO 0-999 999H2S 0-100 250“CO Plus”(Cal. to CO)

0-999 999

“CO Plus”(Cal. to H2S)

0-50 150

Appendix G: Biosystems Standard Warranty Gas Detection ProductsBiosystems Standard Warranty Gas Detection ProductsGeneralBiosystems LLC (hereafter Biosystems) warrants gas detectors, sensors and accessories manufactured and sold byBiosystems, to be free from defects in materials and workmanship for the periods listed in the tables below.Damages to any Biosystems products that result from abuse, alteration, power fluctuations including surges and lightningstrikes, incorrect voltage settings, incorrect batteries, or repair procedures not made in accordance with the Instrument’sReference Manual are not covered by the Biosystems standard warranty.The obligation of Biosystems under this warranty is limited to the repair or replacement of components deemed by theBiosystems Instrument Service Department to have been defective under the scope of this standard warranty. To receiveconsideration for warranty repair or replacement procedures, products must be returned with transportation and shippingcharges prepaid to Biosystems at its manufacturing location in Middletown, Connecticut, or to a Biosystems AuthorizedWarranty Service Center. It is necessary to obtain a return authorization number from Biosystems prior to shipment.THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES AND REPRESENTATIONS,EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO, THE WARRANTY OF FITNESS FOR A PARTICULARPURPOSE. BIOSYSTEMS WILL NOT BE LIABLE FOR LOSS OR DAMAGE OF ANY KIND CONNECTED TO THE USE OFITS PRODUCTS OR FAILURE OF ITS PRODUCTS TO FUNCTION OR OPERATE PROPERLY.

Instrument & Accessory Warranty PeriodsProduct(s) Warranty PeriodPhD5, PhD Lite, PhD Plus, PhD Ultra Cannonball3, , MultiVision,Ex Chek, Toxi, Toxi/Oxy Plus, Toxi/Oxy Ultra As long as the instrument is in service

Toxi/Oxy Pro, MultiPro 2 years from date of purchase

Toxi/Oxy Limited2 years after activation or 2 years afterthe “Must Be Activated By” date,whichever comes first

Mighty-Tox90 days after activation or 90 daysafter the “Must Be Activated By” date,whichever comes first

Mighty-Tox 2Prorated credit is given towards repair or purchase of a new unit ofthe same type.

0 – 6 months of use 100% credit6 – 12 months of use 75% credit

12 – 18 months of use 50% credit18 – 24 months of use 25% credit

IQ Systems, Series 3000, Airpanel, Travelpanel, ZoneGuard,Gas Chek1 and Gas Chek4 One year from the date of purchase

Battery packs and chargers, sampling pumps and othercomponents, which by their design are consumed or depletedduring normal operation, or which may require periodicreplacement

One year from the date of purchase

Sensor Warranty PeriodsInstrument(s) Sensor Type(s) Warranty

PeriodO2, LEL**, CO, CO+, H2S & Duo-Tox 2 YearsPhD5, PhD Lite, PhD Plus, PhD

Ultra, Cannonball3, MultiVision,MultiPro, Toxi/Oxy Pro All Other Sensors 1 Year

LEL**, CO, CO+, H2S 2 YearsToxi, Toxi/Oxy Plus, Toxi/Oxy Ultra,Ex Chek All Other Sensors 1 YearAll Others All Sensors 1 Year

** Damage to combustible gas sensors by acute or chronic exposure to known sensor poisons such as volatile lead (aviation gasolineadditive), hydride gases such as phosphine, and volatile silicone gases emitted from silicone caulks/sealants, silicone rubber moldedproducts, laboratory glassware greases, spray lubricants, heat transfer fluids, waxes & polishing compounds (neat or spray aerosols),mold release agents for plastics injection molding operations, waterproofing formulations, vinyl & leather preservatives, and handlotions which may contain ingredients listed as cyclomethicone, dimethicone and polymethicone (at the discretion of BiosystemsInstrument Service department) void Biosystems’ Standard Warranty as it applies to the replacement of combustible gas sensors.