Model D7 Polarimeter

Model D7 Polarimeter

User Guide

DECLARATION OF CONFORMITY

According to ISO/IEC Guide 22 and EN 45014

Manufacturer's Name Bellingham & Stanley Ltd. Manufacturer's Address Longfield Road, Tunbridge Wells, Kent TN2 3EY United Kingdom declares that the product Product Name Model D7 Polarimeter Model Number All is designed to conform to the following Product Specifications: Safety BS EN 60950-1:2002 EMC Emissions

BS EN 61000-6-3:2007 Emission for residential, commercial and light- industrial environments

Immunity BS EN 61000-6-2:2007 Immunity for industrial environments Supplementary The product herewith is designed to comply with the

requirements of the EMC Directive 89/336/EEC.

This symbol is an internationally agreed indicator that the product bearing it should not be disposed of as general waste or garbage which might end up in landfill sites, but should instead be sent for special processing and/or recycling in those countries where appropriate legislation and facilities are in place.

This symbol indicates a caution or warning, please refer to the manual.

Model D7 User Guide (Eng)

B+S Code : 31-360 Issue 1D

August 2013

Copyright Bellingham + Stanley Ltd. 2013

Every effort has been made to ensure the accuracy of the contents of this manual. However, Bellingham + Stanley Ltd. can assume no responsibility for errors contained in the manual or their consequences. Printed in United Kingdom.

Bellingham + Stanley Bellingham + Stanley Longfield Road 90 Horizon Drive Tunbridge Wells, Kent TN2 3EY Suwanee, GA 30024 United Kingdom United States of America Main: +44 (0) 1892 500400 Main: (678) 804 5730 Fax: +44 (0) 1892 543115 Fax: (678) 804 5729 [email protected] [email protected]

Unpacking the instrument Carefully remove all of the packing material. It is recommended that the box and other packing materials are retained so that, should the need arise, the polarimeter can be safely returned to the manufacturer. Check that all parts listed below are present and that no transit damage has occurred. If any are damaged or missing, contact the supplier immediately. Contents list B+S code Model D7 Polarimeter complete with accessories 31-02 comprising: 1 Power supply 70-180 1 C8 socket mains adaptor 70-181 1 Mains adaptor see below for part number 1 Operating Instructions 31-360 1 Instruction manual CD 55-300 1 Glass sample tube (200mm) 35-30 1 Zero adjust tommy bar 31-166 Part Numbers Mains adaptor part numbers

Description UK

Version Euro

Version US

Version

Mains adaptor (for use with 70-180) 70-182 70-184 70-183

Select the required mains adaptor and fit to power supply. A suitable mains lead should be purchased locally for use with the C8 socket mains adaptor. Positioning the system Place the instrument on a flat and stable bench which is:

• dry and indoors • away from draughty or hot equipment like fans or heaters • out of direct sunlight • away from potential sources of interference, such as RFI generating equipment

Set the instrument up on the bench with the analyzer head facing the operator. Open the hinged chamber cover of the instrument (behind the head) and remove any packaging and the zero adjust tommy bar from the chamber.

Switching on and off Plug the DC cord into the instrument and connect to a suitable mains supply.

Ensure the intensity of the light source is set low before looking down the field telescope by turning the intensity control anti-clockwise.

Initial adjustment Focus by sliding the eyepiece. The scale telescope (top eyepiece) will show the scale and index line. Note that this telescope is illuminated by ambient light via a window on the back of the analyser head. Remove the transit spring from the boss of the control wheel to allow it to engage with the scale within the analyser head. Look through the scale telescope and turn the control wheel until the index line coincides with the 0° scale line.

Without disturbing the setting, look through the Field Telescope and adjust the intensity control. The intensity of the field can be carried out at any time during the use of the instrument. By means of the control wheel, move the scale a few degrees about the 0° position, observing the effect on the field. The field is divided into two halves which will rapidly change in intensity as the control wheel is rotated; as one side increases in intensity the other will decrease in intensity. While rotating the control wheel and viewing through the field telescope, take care to adjust the level of light that is comfortable by using the intensity control.

Scale Telescope

Control Wheel Field Telescope

Intensity Control

Power requirements Voltage 110 to 230 V~ ±10% Frequency 50 to 60 Hz Maximum current (AC) <50 mA Power supply adapter 70-180

RISK OF ELECTRIC SHOCK: • For electrical safety information, read the label on the power supply. • For indoor use only. • Must be kept dry. • Disconnect the equipment from the mains supply before unplugging the lead

from the D7. • Do not open the power supply adapter. No user serviceable parts inside. WARNING: • Do not cover, designed to operate with free air convection. • No cleaning required.

Maintenance warning

WARNING: This product contains a Class 1M LED. If the instrument is to be dismantled, please be aware that the LED light source is safe unless viewed using an optical instrument, such as a loupe or magnifying glass.

Principle of operation This instrument is used to quantify how optically active a sample is by measuring the rotational change that has occurred in the plane of vibration of the plane polarized light as it travels through the sample.

This instrument is a half-shadow type polarimeter with a fixed polarizer and rotating analyser (a second polarizer). The analyser is mounted on a graduated scale to measure the amount it has been rotated. The analyser determines the polarization of the beam of light as it exits the sample chamber. If the plane of vibration of the polarized beam and the analyzer are crossed, mutually perpendicular to each other, the light is extinguished. If the polarized plane of vibration of the beam and the analyzer are matched, so that they are parallel, maximum transmittance occurs. The intensity of light transmitted therefore varies between these two states. The view through the Field Telescope shows the 'half-shadow effect'.

The field is divided into two halves by a thin plate of quartz called a half-wave plate, positioned over half the field before light enters the sample chamber. The half-wave plate changes the plane of polarization in one half, so it mirrors the other half (see the black arrows shown). If the analyser direction (red arrow) is perpendicular to the line of separation, both halves will have equal but low intensity referred to as the 'dark match'.

As the analyser is rotated, one side brightens as the other darkens. There are four positions in 360° where the intensity of the two halves are equal. Two are dark matches at 0° and 180°, and the other two bright matches at 90° and 270°. Neither of the bright matches can be used for measurement. The instrument has been configured to read using only the dark matches. For this reason either of the dark matches can be set in the zero position and used for measurement.

A

The plane of vibration of polarized light after passing through the sample. The sample has rotated the plane of the polarized light by A°.

Plane of vibration of polarized light before the sample.

Reading the scale The scale is viewed through the scale telescope. Turning the control wheel will move the scale, with the index line remaining fixed. The top scale reads Degrees Angular in °A, and is divided at 1° intervals from 0° to 360°. The bottom scale reads the International Sugar Scale (I.S.S) in °Z, divided at 1° intervals, spanning +130°Z to -30°Z. The I.S.S. scale may be used directly in the evaluation of sugar solutions. A reading is taken by using the micrometer drum to move the scale, so that the index line is coincident with a scale division. The scale and the micrometer drum readings are added to give an overall reading. Ensure that the same units are used on both the scale and the micrometer drum. Use of the micrometer drum The micrometer drum sub-divides the degrees angular and I.S.S. scales further and has two corresponding scales, angular on the left, sub-divided at intervals of 0.05°A, and I.S.S. on the right, subdivided at intervals of 0.1°Z. The index marker for the micrometer drum is at the top of the aperture for both scales. It will be noted that movement of the drum from 0 to 1.0 will cause the index line seen through the scale telescope to transverse exactly one scale division respectively for the I.S.S. and degrees angular scales.

The micrometer drum is rotated by turning the knurled disc, and is used to adjust the scale viewed through the scale telescope until the index line coincides with the nearest lowest scale division. The micrometer drum does not act as a fine control to the view observed through the field telescope and will not change it. It serves only to sub-divide the scale once a balance in the field view has been obtained.

Micrometer drum knurled disc

Clamp knob

°Z, International Sugar Scale

°A, Degrees Angular Scale

Measuring a sample Starting with an empty sample chamber, check the instruments calibration. View through the scale telescope and use the control wheel to set the scale to 0° by coinciding the index line with the 0° scale line. Ensure the micrometer drum is also set to zero. With the scale set to zero, the view through the Field telescope should appear in the dark match condition, each side at an equally low intensity. Move the control wheel back and forth to check that the scale still reads 0° when adjusted to the dark match condition. If the scale does not read zero, follow the instructions on page 9 to zero the instrument. The half-shadow image in the dark match condition (shown on the right), has black arrows indicating the plane of polarization in each half of the field, and the red arrow indicates the plane of polarization of the analyzer. Place the sample into the sample chamber and if possible close the chamber cover. If the sample is optically active it will rotate the plane of polarization that entered the sample (noted by the blue arrow). The black arrows also illustrate this rotation equally applied to each half of the field. The analyser, still perpendicular to the field separation (shown in red), now has its plane of polarization crossed to the plane of polarization on the right hand side, extinguishing the light. To measure the amount of rotation produced by the sample, the control wheel is used to rotate the analyser (and scale) to regain the dark match condition in each half (this movement is illustrated by the red arrows). To regain the dark match, the analyser would have to be rotated by the same amount the sample rotated the plane of polarization. As the scale is locked to the analyser, the amount of rotation can be quantified. Once the half shadow has been set back to the dark match condition, return to the scale telescope and use the micrometer drum to move the scale until the index line coincides with a scale division. Add the scale reading and the drum reading together, ensuring that both readings are either in °A or °Z (I.S.S.). E.g. The scale shown has had the index line coincided with the 26°Z division, (lower scale) by adjusting the micrometer drum. If the drum reads 0.3°Z, the reading will be 26.3°Z.

Sample tubes and filling The beam of light that will pass through the tube once inside the chamber should not reflect off the inner wall of the tube. Therefore only tubes suitable for the beam produced by the Model D7 should be used. Sample tubes should have an inner bore of at least 6mm. The outer diameter of the tube supports should be 30mm, to position the tube centrally to the 4mm diameter light beam. To obtain accurate results, great care must be exercised in filling the tube and ensuring that the end windows are not strained, thus causing erroneous results. For a bubble type sample tube Remove both tube end caps and detach the glass windows, which must be carefully cleaned and dried along with the tube and end caps. Place one window over the end of the tube and replace the cap. Carefully screw the cap down until the first resistance is felt. Do not over tighten, as stress may be applied to glass window. Invert the tube, and ensuring that the open end is clean and dry, pour in the sample carefully until a meniscus appears bulging above the tube end. The second window may now be slid from the side over the tube end with one movement and centralised without tilting. Replace the end cap as before, and tap the tube gently to dislodge any small bubbles into the bubble trap at the centre of the tube to keep them out of the way of the light beam. For a central filling type sample tube Remove both tube end caps and detach the glass windows which must be carefully cleaned and dried along with the tube and end caps. Replace both windows and end caps, taking care only to screw the caps down until the first resistance is felt. Do not over tighten, as stress may be applied to glass window. Fill the tube with sample through the central filling tube. Tap the tube gently so any bubbles dislodge and move up the central tube. The introduction of a filled sample tube into the sample chamber may put the image through the Field telescope out of focus. The field telescope view must be focused to a sharp image when taking a reading. This adjustment can be carried out at any time without effecting the instruments calibration. Precautions Stress on the sample tube glass windows can cause the glass to read a small rotation, giving some error to a measurement. It should be possible to seal a tube by tightening end caps only finger tight, so not to cause a level of stress that will effect the reading. It is recommended that some investigation should be carried out by the user to obtain a feel of this. A tube filled with water should show no rotation, so can be used as an indicator of good technique. The path of the beam of light through the sample should not be interrupted by bubbles or particulates within the sample tube. When filling a tube with liquid, ensure that there are no air bubbles in the tube that could obstruct the light by looking down the tube's length. For dark samples the intensity control is capable of illuminating samples up to an optical density of 2. If the field view is indistinguishable use a shorter tube to reduce the optical density.

Adjusting the zero calibration With an empty sample chamber and the scale set to read 0°, a dark match condition should be viewed through the field telescope. The dark match condition is met when both halves of the field have an equally low intensity. If this is not met the instrument should be zeroed. First check the amount of error by adjusting the control wheel so that the dark match condition is precisely met. Take a reading using the scale and micrometer drum. If the reading is within ±0.5°A (degrees angular), the micrometer drum can be used to adjust the instruments calibration. If the dark match condition is greater than ±0.5°A away from 0°, an adjustment should be made to the analyser position relative to the scale first. Minor Adjustment - Micrometer Drum With the field set up in the dark match condition, hold the micrometer drum knurled disc while loosening the clamp knob. The drum scale is now released from the knurled disc.

View the scale through the Scale telescope and turn the knurled disc until the index line coincides with the 0° scale line as shown. Without moving the micrometer drum knurled disc, slide the drum scale down so that the micrometer drum is set to zero. While holding the knurled disc stationary, re-tighten the clamp knob to secure the zero position. There is only a certain amount of travel on the micrometer drum during this calibration. If the drum divisions are becoming obscured by the sides of their aperture while the drum clamp knob is released, use the knurled disc to adjust the drum so that it sits in the

centre of its travel. Re-tighten the clamp knob and use the analyser adjustment first. Major Adjustment - Analyser To adjust the analyser position in relation to the scale, with the aim to leave only a small error that can be taken up by the micrometer drum adjustment. Set the micrometer drum and scale to 0°. Open the sample chamber cover and find the holed ring of the analyser mount located behind the analyser head. The tommy bar provided fits into one of the holes and is used to rotate the analyser mount. Before adjusting the analyser mount, lock the scale by pushing and holding the control wheel inwards. While holding the control wheel firmly and viewing through the field telescope, adjust the analyser with the tommy bar to bring the half-shadow as close to a dark match as possible. Once the analyser has been adjusted, use the control wheel to meet the dark match condition precisely. Check the zero error is now within the adjustment range of the micrometer drum by taking a reading. If the dark match does not occur within ±0.5°A (degrees angular), repeat the adjustment. Once the error is within ±0.5°A, follow the instructions for the micrometer drum adjustment to zero the instrument.

Specifications

°A Degrees Angular Scale °Z International Sugar Scale

Measurement range 0 to 360 -30 to +130

Sub division 1 1

Resolution by micrometer drum 0.05 0.1

Reading by estimation ±0.02 ±0.05

Light emitting diode with interference filter

589 nm

Beam diameter, nominal 4 mm

Ambient operating temperature, °C 5 to 40

Storage temperature, °C 5 to 40

Voltage 110 to 230 V~ ±10%

Frequency 50 to 60 Hz

Maximum current (AC) <50 mA

Dimensions, packed, cm 56 x 40 x 30

Footprint, bench space, cm 30 x 16

Gross weight, kg 9

Net weight, kg 5.5

Spares and accessories

B+S code

Quartz Control Plate nominal 100°Z (34.6°Angular) 34-20

Quartz Control Plate nominal 15°Z (5.2°Angular) 34-21

Quartz Control Plate nominal –30°Z (-10.4°Angular) 34-22

QCP UKAS certificate of calibration traceable to PTB 90-803

English instruction manual 31-360

French instruction manual 31-361

Spanish instruction manual 31-362

German instruction manual 31-363

Low strain cover glasses 15.5mm diameter (pack of 12) 35-60

Rubber washers for use between cover glass and end cap (pack of 12) 35-64

End caps, plastic. (pack of 2) 35-68

100 mm Standard glass sample tube with bulb 35-29

200 mm Standard glass sample tube with bulb 35-30

Power supply 110-230V 70-180

Mains adaptor for 70-180: C8 socket version 70-181

Mains adaptor for 70-180: UK version 70-182

Mains adaptor for 70-180: US version 70-183

Mains adaptor for 70-180: Euro version 70-184

Quick Start Guide The quick start guide is provided as a short introduction to the use of the Model D7 polarimeter and as a reminder in the event of infrequent use. Please make sure that reference is made to the full manual, especially in respect of initial installation and any warning statements contained within.

1. Check Zero with an empty chamber or zero sample (page 9)

• Set Micrometer drum to “0”. • Using control wheel set the scale to “0”. • Set the Intensity Control knob to the minimum settings by turning it

anti-clockwise. • View the field telescope, adjust Intensity Control knob to reach a

comfortable intensity. • View the field telescope, ensure dark match by moving control wheel

back and forth. • With the dark match visible in the view field check that scale still reads

“0” exactly, if not the instrument requires calibration (see page 9).

2. Place polarimeter tube containing the sample in the measurement chamber (page 7) • Close the chamber lid if possible. • TIP – make sure there are no bubbles in the tube.

3. View the image through the field telescope (page 3) • The field telescope is the lower eyepiece; an optically active sample

will cause the dark match to be lost.

4. Balance the image by rotating the control wheel (page 3) • WARNING – take care not to view at highest intensity. • TIP - Intensity control may be used to adjust the overall intensity of

the image. This will not effect the measurement.

5. View the scale through the scale telescope (page 3) • The scale telescope is the upper eyepiece.

6. Micrometer drum adjustment (page 6) • Move the scale using the micrometer drum so that the vertical index

line is aligned with a scale division.

7. Record Measurement (page 6) • Obtain the measurement by adding the scale value to that of the micrometer drum. • TIP – make sure you add the corresponding scale values, see table below.

Scale Field View Micrometer Drum °A Top scale Left hand scale °Z Bottom scale Right hand scale

Model D7 Polarimeter

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