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Capacitance-Based

PressureTransducerHandbook

Understanding,specifying and applying

Capacitive Pressure Transducers

Useful information forevery design engineer

T E C H N I C A L D A T A

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The sensing and measurement of physical quan-tities through small changes in electrical capaci-tance is scarcely a new concept. The natural ben-

efits of this approach were recognized for many years.But it was not until Setra engineers introduced new ma-terials, new designs, and innovative, dedicated circuitrythat the technique’s full potential was realized in thepractical, real world of pressure measurement.

Today, capacitive pressure transducers are widely usedin both highly-specialized and general equipment ap-plications that call for thoroughly dependable accuracyand/or long-term stability. They are especially in de-mand wherever a job involves adverse operating con-ditions, such as shock, vibration, temperature extremes,etc. Designers and engineers find that the electrical sim-plicity and inherently rugged mechanical structure ofthe typical capacitive sensor result in relative freedomfrom the problems to which more glamorous techniquesare usually susceptible.

The specific facts and data on the following pages willhelp to introduce you to capacitive pressure transduc-ers (if you are not already familiar with them), and willassist you in evaluating their applicability to pressuremeasurement problems that call for more than offhandsolutions.

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PageIntroduction to Capacitive Pressure Transducers 4 - 7

Comparison with Strain GaugeTransducer Types 8

Capacitive Pressure Transducer Applications 9

Transducer Electrical Connections 10 - 11

How Setra Specifies its PressureTransducers 12 - 14

A Glossary of Pressure Terms 15 - 16

Setra Transducer Selection Guide 17

Specifying Capacitive Pressure Transducers 18

Pressure Conversion Chart 19

C O N T E N T S

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An Introduction toCapacitance BasedPressure Transducers

Equipment designers today can choosefrom an impressive array of commer-cially available pressure transducers.Sensing devices range from modernversions of the venerable manometerand Bourdon tube, through bondedstrain gauges to sophisticated unitsusing, deposited or ion-implantedpiezoresistive semiconductor elementson silicon or sapphire substrates.

And the list goes on, to include suchspecial-purpose types such as LVDT,variable reluctance, Hall effect,inductive and potentiometric devices.

Although most of these transducersperform acceptably in specific applica-tions, virtually all have inherentoperating and performance limitations.Selection of a particular transducer typeis usually a trade-off in which certainacknowledged disadvantages aretolerated in order to achieve a desiredresult. Lower cost, for example, is oftenbought at the expense of long-termstability...or accuracy...or reliability.

In this somewhat overcrowded pressuretransducers field, Setra capacitivedevices stand out as perhaps the closestthing to a universal pressure transducerstyle. They have generally broaderapplication, greater overall reliabilityand physical ruggedness, and in mostcases, require fewer trade-offs thanother types. Costs, while often thoughtto be higher, are actually extremelycompetitive in quantity.

CapacitiveTransducers...functional simplicity/structural sophistication

Setra’s capacitive pressure transducers areexpertly designed adaptations of a simple,durable and fundamentally stabledevice...the electrical capacitor.

In a typical Setra configuration, a compacthousing contains two closely spaced,parallel, electrically-isolated metallicsurfaces, one of which is essentially adiaphragm capable of slight flexing underapplied pressure. The diaphragm isconstructed of a low-hysteresis materialsuch as 17-4 PH SS or a proprietarycompound of fused glass and ceramic(Setraceram™). These firmly

.036 CU. INVOLUME

Typical capacitive pressure sensor, showing ruggedconstruction. Materials are carefully selected forcompatibility to minimize environmental effects.(Capacitance gap is accentuated for illustration.)

Gold PlatedSurface

CeramicWafer

AirDielectric

Diaphragm(conductivesurface)

SensorBody

}

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secured surfaces (or plates are mountedso that a slight mechanical flexing of theassembly, caused by a minute change inapplied pressure, alters the gap betweenthem (creating, in effect, a variable capaci-tor).

The resulting change in capacitance isdetected by a sensitive linear comparatorcircuit (employing proprietary, custom-designed ASICs), which amplifies andoutputs a proportional, high-level signal.

The inherent simplicity and ruggedness ofthis physical configuration, the fact thatall wettable parts are of stainless steel orlow-hysteresis ceramic, and a carefulmarriage of the mechanical assembly tothe electronic circuitry, all combine to cre-ate a transducer that exhibits uniformlysuperior performance and reliability.

ComparativeOperating Features

High AccuraciesDepending on application requirements,Setra transducers can provide accuraciesas high as ±0.02% FS. Such precision, notattainable by many other transducer types,is particularly useful in test-and-measure-ment applications, barometric standardstransfer, altimetry, etc.

Minimal Mechanical MotionA measurable voltage change is producedby a very slight change in capacitor plate

gap. The extremely small deflection ofSetra sensor diaphragms helps to minimizehysteresis and repeatability errors and toprovide very fast response times.

Broad Range CapabilitiesSetra transducers provide an unusuallybroad selection of pressure ranges. Pressurefrom 0.05 in. W.C. to 10,000 psig can bemeasured accurately and consistently.

Long Term StabilityAll Setra transducers are designed and speci-fied to maintain accuracy settings longerthan competitive units. Unlike sensors suchas bonded strain gauges, capacitive trans-ducers exhibit extremely low creep, agingeffects, humidity effects and other commonenemies of output stability. Setra transduc-ers provide long-term zero stabilities as lowas 0.05% FS/yr.

AppliedPressure

StretchedDiaphragm

Electrode

ReferencePressure Port

}

Cross-section of Setra’s Model 239 — a high-accuracy, low differential pressure transducer.Its unique, thermally-stretched diaphragmcombines high sensitivity with optimum accuracy(0.14% FS) and thermal characteristics(Operating from 30°F to 150°F with <±1% FS/100°F thermal effect). (Capacitor gap anddeflection accentuated for illustration.)

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SetraTypical Pressure Transducer Types

Model 204High Accuracy/Broad Range

Test & Measurement

Model 760Capacitance manometer

Absolute Pressure transduceTest & Measurement

Models 206/207Industrial/OEM

Models 209Industrial/OEM

Models 270High Accuracy/Low Medium Pressure

Setraceram — Barometric Use

Models 230Wet/Wet

Process Control — HVAC — Etc.

Models 230 w/3-Valve ManifoldWet/Wet

Process Control — HVAC — Etc.

Models 239High Accuracy/Low Differental Pres.

HVAC — R&E — Environmental

Models 264Low Differential Pressure

HVAC

Models 224Flow-Through

Ultra-High Purity Applications

Models 201Low Differential Pressure

Industrial

Models C-290Flush Diaphragm/3A Sanitary

Beverage/Dairy/Food Processing

Datum 2000 SeriesDual-Channel Digital display/Manometer

Bench-top/Panel-mountreference-Analog display

Models 370 & 470Environmental Monitoring and

Test and Measurement

Ultra-LowPressure

Generatingand

DocumentingCalibrator

Micro-Cal Model 869

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High-Level OutputSetra transducers need no signal am-plification. As a result, they avoid prob-lems common to low-level output de-vices, such as piezoresistive (thin filmand IC) types. Such problems normallyinclude poor long-term stability, ther-mal instability, high RFI susceptibilityand humidity effects.

Broad Media CompatibilityAll wetted parts of Setra sensors are ei-ther of stainless steel or tough ceramicmaterial. As a result, they can handle awide range of difficult fluids, includ-ing acids, salt solutions, corrosive gas-ses and liquids with high particulatecontent.

High ElectromagneticCompatibility (EMC)Setra’s sturdy metal cases, shieldedcables and careful construction, to-

gether with the high-level output char-acteristic of capacitive sensing, ensurehigh immunity to external radio fre-quency and electrostatic discharge in-terference. Similarly, they are essen-tially immune to radio frequency inter-ferences emissions.

Resistant to Harsh EnvironmentsSetra’s transducers are tough! Thosemodels designed for industrial use arespecified to withstand a minimum of 10million full scale cycles with specifiedaccuracy and thermal performance.When they are installer per ANSI B40.2applying a maximum of 75% F.S. pres-sure, they will exhibit unlimited cyclelife. What’s more, all industrial units arecertified to between 100 G and 200 Gshock loading, and can withstand vibra-tion at minimum peak amplitudes from10 G to 20 G.

Transducer Characteristic In use, this translates to...High-Level Output Better Accuracy - High Stability

Lower RFI Vulnerability

Rugged, Shielded Construction Broad Media CompatibilityHigh Shock & Vibration ToleranceHigh Electromagnetic CompatibilityHigh Resistance to Harsh Conditions

Proprietary, Linear Circuitry Highest Accuracy

Carefully Selected, Excellent Temperature StabilityCompatible Materials Minimum Humidity Effects

Minimum Mechanical Motion Low Hysteresis - High Repeatability

Capacitive Sensing High Sensitivity -Accurate Low-Pressure Sensing

Capacitance-Based Pressure TransducersSUMMARY OF CHARACTERISTICS

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Comparative CharacteristicsCapacitance v. Strain Gauge Sensors

MEASUREMENT Aver. Aver. Aver. HighACCURACY

LONG-TERM Low Aver. Aver. HighSTABILITY

OUTPUT High Low Low HighLEVEL

HYSTERESIS Aver. Aver. Aver. Low

CREEP High. Low Low. None

FREQUENCY Fast Limited Aver. FastRESPONSE

MEDIA Limited Limited Limited HighCOMPATIBILITY

AGING Aver. Aver. Aver. Virtually NoneEFFECTS

PRESSURE Limited Limited Limited BroadRANGE

TEMPERATURE Extensive Extensive Extensive MinimalCOMPENSATION

EMI/RFI Aver. High High MinimalSUSCEPTIBILITY

RUGGEDNESS Fair-Low Fair-Low Fair-Low High& RELIABILITY

BONDED THIN FILM IC

Strain Gauge Transducers SETRACapacitive

Transducers

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CapacitivePressure TransducerAPPLICATIONS

Because they have earned a reputation forconsistently high accuracy and unmatchedlong-term stability, Setra pressure sensorsfind broad application in areas wherecharacteristics rate from important tovital. A few of these include:

Test & Measurement• Turbo-jet/Turbo-fan aircraftengine test stands - internalpressure measurements atmultiple points.

• Engine test stands for Autobus-Europe

• Wind tunnels

• Dynamometers

• Stack gas monitoring & analysis

• Medical instrumentation

• Hydraulic and Pitot static aircrafttest systems

• A broad range of instruments,including laser interferometers,porosimetry instruments, particlemeasuring systems, automatedsorption analyzers, etc.• General R & D and MetrologyLaboratory applications

Industrial & Military• High-speed compressors

• Process control systems

• Canning/bottling systems

• Off-road vehicles

• Dairies - breweries

• Tank level measurement systems

• Helicopter missile-launch control

systems

• Military surveillance equipment

• Semiconductor processing equip-ment

• Pharmaceutical and biotechnologyprocessing

• Natural gas lines

• Off-shore drilling equipment

• Freeze drying equipment

Heating, Ventilating, Air

Conditioning (HVAC)• HVAC and VAV control systems

• Energy management systems

• Clean room control

• Filter condition monitoring

• Fume hood control

• Pump speed control

• Hospital isolation wards

Barometric applications• Presently in use at over 400 remoteLand & Sea Weather Stations

• In use at over 500 airports as part ofAWOS (Automated Weather Observ-ing Systems) and ASOS (AutomatedSurface Observation Systems), forautomatic barometric pressurereporting

• Used in weather stations throughoutthe U.S. and Canada

• In use by major weather systemsmanufacturers in Europe

• Widely used as transfer pressurestandards

• Used by many airports and avionicsshops for altimeter recertification

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●

●

2-Terminal Transmitter WiringFOR USE WITH ALL CURRENT OUTPUT (4-20 mA) MODELS

ElectricalCONNECTIONS

3-Terminal Transducer WiringFOR USE WITH SETRA MODELS 207, 264 AND 280E

3-Terminal Transducer WiringFOR USE WITH SETRA MODELS 206, 209, 212FT, 276

Power SupplyVDC

AnalogDevice

SETRA4-20 mAOutput

Transmitter

PowerSupply

VDC

AnalogDevice

SETRA3-Wire

Voltage OutputTransducer

PowerSupply

VDC

AnalogDevice

SETRAVoltage Output

Transducer

+-

+-

+

-

Ground

+

--

+

COM

+EXC (IN)

+Out

Ground

-

-

+EXC

-EXC

+Out

Ground

+

+

-Out

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4-Terminal Transducer WiringFOR USE WITH SETRA MODELS 204, 204D, 205-2, 206*, 212FT*, 239, AND 270

PowerSupply

VDC

AnalogDevice SETRA

3-WireVoltage Output

Transducer

*Models 206, 212FT can be wired as 3-wire devices by connecting -Output, -EXCand shield to a common ground.4-wire transducers can only be grounded at either -EXC or on the -Output becausea common mode voltage exits. (See Common Mode Voltage, below.)

Common Mode Voltage4-WIRE MODELS ONLY - MODELS 204, 204D, 205-2, 228-1, 239 AND 270

Typically—OUTPUT is approximately 4.7 VDC above the -EXCITATIONRule: You can only common or ground at one location—either -EXC or -OUTPUT

+OUTPUT

(+4.7 VDC) -OUTPUT

+EXC

-EXC

+

-

+

-

+OUTPUT

-OUTPUT

+EXC

-EXC

Ground

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Relationship of a calibration curve to aspecified straight line.

Best Fit Straight Line(BFSL) Method

Example: ±0.1% FS

5.1 VDC

0.1 VDC

0 PSI 100 PSI

Used for non-linearity measurement on all SetraPressure Transducers except Model 270, 276, 370and 470.

SpecificationsDERIVATIONS

Expressed in %FS at constant temperatureAccuracy as RSS non-linearity, hysteresis and non-repeatability

ROOT SUM SQUARES (RSS)

NON-LINEARITY (±0.1%)2 = 0.01%

HYSTERESIS (±0.05%)2 = 0.0025%

NON-REPEATABILITY: (±0.02%)2 = 0.0004%

0.0129%

= ±0.11% FS at constant temperature

5.0 VDC

0 VDC

0 PSI 100 PSI

Used for non-linearity measurement on Models270 and 276.

Relationship of a calibration curveto a specified straight line throughits end points.

End Point Method

Example: ±0.05% FS

√0.0129%

Accuracy

Non-Linearity Non-Linearity

-0.05% FS+0.05% FS

+0.1% FS

-0.1% FS

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0 PSI 100 PSI

Used for non-linearity measurements on Models370 and 470.

Relationship of a calibration curveto a specified straight line with endpoints at zero and full scale.

Terminal Method

Example: ±0.012% FS

Non-Linearity

+0.012% FS

-0.012% FS

RS23

2 O

UTP

UT

0 PSI 100 PSI

The maximum difference in outputat any pressure value within thespecified range, when the value isapproached with increasing anddecreasing pressure.

Hysteresis

0 PSI 100 PSI

The ability of a transducer toreproduce output readings whenthe same pressure value is appliedto it consecutively, under the sameconditions, and from the samedirection.

Non-Repeatability

0 PSI 100 PSI

The ability of a transducer toreproduce output readings ob-tained during its original calibrationat room conditions for a specifiedperiod of time.

Long Term Stability

Example: (Model 270):±0.1% FS over 6 Months

at 70°F (21°C)

Original calibrationAfter 6 months

5 VDC

0 VDC

5 VDC

0 VDC

<0.02% FS

5 VDC

0 VDC

<0.05% FS +0.1% FS-0.1% FS

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Zero output is factory set to withina certain % of full scale. Results in ashift up or down of the calibrationcurve. Does not affect linearity oraccuracy.

Zero Offset

Span output is factory set to within acertain % of full scale. Results in achange in the slop of the curve.Does not affect linearity or accuracy.

Span Offset

The change in the zero and spanoutput that occurs due to tempera-ture changes.

Thermal Zero Shift: <±0.4% FS/100°FThermal Span Shift: <±0.3% FS/100°F

Example Temp. Range -10°F to ±130°F

Max. temp change from 70°F = 80°F

80°F x 0.4% = 0.32% FS DZ/DT80°F x 0.3% = 0.24% FS DZ/DTZ shift = <±0.32% FSS shift = <±0.24% FS

(Worst Case) Over a TemperatureRange of -10°F to 130°F

Non-Linearity: ±0.1% FS

Hysteresis: ±0.05% FS

Non-Repeatability: ±0.02% FS

Thermal Zero Shift: <±0.32% FS

Thermal Span Shift: <±0.24% FS

Zero Offset: ±0.2% FS

Span Offset: ±0.2% FS

±1.13% FS

Thermal Effects Total Error Band

Long-term stability error not included.

0 PSI 100 PSI

+0.01% FS -0.01% FS

+0.01% FS-0.01% FS

Zero shift +0.2% FSNo span shiftLinearity still ±0.1% FS

No zero or span shiftLinearity ±0.1% FS

2% FS(10 mV)

+0.1% FS

-0.1% FS

+0.1% FS-0.1% FS

Span shift +0.2% FSLinearity shift ±0.1% FS

0.2% FS(10mV)

No span shiftLinearity ±0.1% FS

0 PSI 100 PSI

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GLOSSARY ofPressure Terms

Absolute Pressure — Pressure mea-sured relative to a full vacuum. Referredto as pounds per square inch absolute(PSIA).

Atmospheric Pressure — Pressureof the atmosphere at the earth’s surfaceNIST standard atmospheric pressure =1.01325 bar.

Bar — Unit of pressure (or stress). 1 bar= 750.07 mm of mercury at 0°C, lat. 45°

Barometric Pressure— Atmo-spheric pressure; often measured in mil-libars, in. Hg (inches of mercury), orhectopascals.

Bourdon Tube — An early, mechani-cal pressure gauge consisting of a flat-tened tube that tends to straighten un-der internal pressure; today usually usedwith a potentiometer to produce an elec-trical output.

Burst Pressure — The maximumpressure that may be applied to the posi-tive pressure port without rupturing thesensing element.

Capacitive Sensing — Detectionand measurement of pressure throughthe change in voltage across a capacitor,one plate of which is a diaphragm whichdeflects slightly with changes in appliedpressure.

Compound Pressure — Pressuremeasured from full vacuum (-14.7 PSIV)to gauge pressure, referencing atmo-sphere.

Differential Pressure — Pressure mea-sured relative to a reference pressure. Referredto as pounds per square inch differential (PSID).

FS (Full Span or Full Scale) — The rangeof measurand values over which a transduceris intended to measure, specified by the upperand lower limits. Ex: 0 to 100 PSIG, FS is 100 PSIG/0 to 5 VDC, FS is 5 VDC, 800-1100 MB, FS is 300MB.

Gauge Pressure — Pressure measuredrelative to ambient atmospheric pressure.Quantified in pounds per square inch gauge(PSIG).

Manometer— An early instrument for mea-suring pressure; originally a U-shaped tube con-taining liquid (water, oil or mercury), one limbopening to the gas volume to be measured, theother closed or connected to a registering orrecording instrument. Modern versions utilizediaphragms, bellows or other devices for sens-ing relative pressures.

Millibar (mbar) — Unit of pressure gener-ally used in barometric measurements; 1 mbar= 100 N/m2, or 1~ dyn/cm2

Newton (N) — The unit of force in the Inter-national System of Units (SI); the force requiredto impart an acceleration of 1 m/sec2 to a massof 1 kg.

Pascal (Pa)—The standard unit of pressure(or stress) in the SI system: equal to 1 newtonper square meter (1 N/m2).

P/I — Term common to process industriesmeaning pressure-in/current-out. (3-15 PSIGInput to 4-20 mADC Output.).

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Pressure Transducer — An electrome-chanical device for translating pressure val-ues into voltages across a high-impedance(5k ohms or greater) load.

Pressure Transmitter — An electrome-chanical device for translating pressure val-ues into currents (generally 4-20 mA) into alow-impedance load.

Proof Pressure — The maximum pres-sure that may be applied without changingperformance beyond specifications (typi-cally, 0.5% FS zero shift).

PSIA — Pounds per square inch absolute.

PSIV — Pounds per square inch vacuum.

Range — The spread between the maxi-mum and minimum pressures betweenwhich the transducer has been designed tooperate.

Setraceram™ — A patented, ceramic/glass sensing element, used by Setra in baro-metric transducers and instruments requir-ing the highest degree of measurement pre-cision and stability.

Span — The algebraic difference betweenthe limits of the range. EX: 0.1 to 5.1 Volts DC;span is 5 VDC. Sometimes used to designatefull scale output; i.e. 5 VDC.

Torr — A unit of low pressure equal to ahead of 1 mm of mercury, or 133.3 N/m2.

Vacuum — Generally refers to pressuresbetween 0 and atmospheric; often measuredin 0-30 in. Hg Vacuum. Referred to as poundsper square inch vacuum (PSIV).

1 atmosphere0 psig

0 psia 14.7 psia

100 psig

Vacuum Range114.7 psia

Gauge/Absolute Pressure

Hard (high) Vacuum Soft Vacuum

14.7 psia(1 atmosphere)

0 psiv

0 psia

14.7 psiv

Vacuum Pressure

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Altimeter Setting ●Barometric Measurements ●Chillers ● ●Clean Room Control ●Compressor Control ● ●Dynamometers ● ●Energy Management ●Engine Test Cells ● ● ● ●Filter Condition Monitors ● ●Food & Beverage Process ●Fume Hood Control ● ●Gas Bottle Filling Equipment ●General Purpose/Industr. ● ● ● ●Hazardous Locations ● ● ●High Acc. Test & Measm’t ● ● ● ● ● ●HPLC ●HVAC/VAV Control ● ● ● ●HVAC Equipment ● ●Hydraulic/Pneumatic Sys. ● ● ●Intrinsically Safe Duty ● ● ● ●Industrial Engine ●Laser Interferometers ● ●Leak Detection ●Level Measurement ● ● ● ●Medical Instrumentation ● ● ●Natural Gas Lines ● ●OEM Applications ● ● ● ● ● ● ● ●Off Road Vehicles ●Off Shore Drilling ● ● ●Paper Converting Syst. ●P/I Range ●Pharmaceutical Process ● ●Pressure Transfer Stds. ●Process Control ● ● ●Pump Speed Control ● ● ●Refrigeration Equipment ●R&D Scientific ● ● ● ● ●Sanitary Filtration System ● ●Sanitary Pressure Lines ● ●Semicon Equipment ● ● ● ●Specialty Gas Handling ●Test & Measurement ● ● ● ● ●Weather Data Systems ● ●Vacuum Systems ● ● ● ● ●

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-18-

SPECIFYINGCapacitive Pressure Transducers

The following guide will assist you in selecting the type and ratings of the Setrapressure transducer that will do your job best. If you would like a quotation, just faxor mail us a copy of this form for quick response.

ApplicationApplication is ❐ New ❐ Existing Describe _____________________

_________________________________________________________________________________________________________________________________________________________________________________________________________

Model # (if known) ____________ Inital Qty _________ Est. Annual Qty _____________

Pressure Range: _____________ ❐ Gauge ❐ Absolute ❐ Differential ❐ Vacuum

Output: ❐ 0-5 VDC ❐ 1-6 VDC ❐ 4-20 mA ❐ 0.1 to 5.1 VDC ❐ Other _________

Excitation: ❐ 24 VDC ❐ 12 VDC ❐ Other _________________

Media: ❐ Air ❐ Water ❐ Hydraulic Fluid ❐ Other ____________

Environment: ❐ Indoor ❐ Outdoor ❐ Explosion-Proof ❐ Other _____________

Pressure Fitting: ❐ 1/4” NPT (Male) ❐ Flush ❐ 7/16” SAE (male) ❐ Other ________

Electrical Termination: ❐ ________________ ft. Cable (specify length)

❐ Terminal Strip ❐ Other

Temperature Exposure (operating): ❐ 40°F - 100°F ❐ 0 to 175°F ❐ -40°F - 185°F

❐ Other __________

Shock: ❐ 50G ❐ 100G ❐ 200G ❐ Other ____________

Vibration: ❐ 5G ❐ 10G ❐ 20G ❐ Other ____________

Electrical Interference: Specify Potential Noise (field strength & frequency)

Options: ____________________________________________________________

__________________________________________________________________________

Remarks __________________________________________________________________________________________________________________________

__________________________________________________________________________

Name: _____________________________________ Title: __________________________

Organization: ______________________________ Division: _______________________

Address: ___________________________________________________________________

City/State/Zip: ______________________________________________________________

Phone: ( ) _______________________________ Fax : ( ) ______________________

Email: _____________________________________

-19-

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6894

.76

1 x

105

100

3.38

6524

9.08

133.

329.

8068

11.

0132

133.

32(N

/m2 )

x 10

3x

105

ATM

6.80

46.9

8692

9.86

923.

3422

2.45

831.

3158

9.67

889.

8692

11.

3158

x 10

-2x

10-4

x 10

-3x

10-3

x 10

-3x

10-5

x 10

-6x

10-3

TOR

R51

.714

975

0.06

.750

0625

.401

1.86

831

7.35

587.

5006

760.

001

x 10

-2x

10-3

-20-

Meet Our EntirePharmaceutical Family...

● Model 264 Pressure Transducer- ±0.25% and ±0.40% FS Accuracies- Excellent Price/Performance Ratio- 3 Year Unconditional Warranty

● Model 267 Laboratory Grade Pressure Transducer

-±0.25% and ±0.40% FS Accuracies- Optional LCD for Critical Applications- Static Probe for Room Pressure- Applications and Direct Duct Mount

● Model 269 High Performance Pressure Transducer- ±0.15% and ±0.35% FS Terminal-Based Output- Non-Linearity- Removable Process Head and Detachable Terminal Block for In-Situ Calibration- Tamperproof Operation via “Security Key” with Push Button “Snap-Back” Zero and Span Adjustment- Base or Din Rail Mount Design - Minimizing Installation Time- Calibration Ready by a Electro-Pneumatic Interface Enabling Multi-Featured Automatic Calibration with Model 869

Setra Systems, Inc.159 Swanson road

Boxborough, Massachusetts 01719Tel: 978-263-1400 or Toll Free: 800-257-3872

Fax: 978-264-0292email: sales@setra.com