VEE GEE C25L User manual

Operation Manual
Model C25L
Cat. No. 4601P
Measurement
Range ±180°
Manual Polarimeter

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VEE GEE C25L Operation Manual
±180° Full Circle Manual Polarimeter
Contents
Introduction........................................................................................... 3
Safety Precautions................................................................................ 3
Maintenance
Fuse Replacement........................................................................... 3
Cleaning.......................................................................................... 3
Parts & Accessories
Components................................................................................ 4-5
Included Parts.................................................................................. 4
Replacement Parts.......................................................................... 5
Setup
Basic Assembly................................................................................ 6
Eyepiece Focusing........................................................................... 6
Operation
Glass Sample Cells........................................................................... 6
Measuring....................................................................................... 6
Instrument Accuracy........................................................................ 7
Troubleshooting................................................................................... 7
Specications....................................................................................... 7
For information about parts, accessories, or service -
contact your VEE GEE dealer or contact VEE GEE Scientic at:
800-423-8842 | veegee.com | [email protected] | [email protected]
Disclaimer: The information provided in this operation manual is believed to be accurate and reliable at
the time of printing. However, no responsibility shall be assumed by VEE GEE Scientic for its use. The
information contained in this document is subject to change without notication.
This product is designed and intended for use only as a polarimeter system. Modifying the product in any
manner for use not originally intended shall automatically void the manufacturer’s warranty. In no event
shall VEE GEE Scientic LLC be held liable for any incidental or indirect damage arising from the use of
modied or altered product.
All rights reserved. No part of this document may be reproduced or transmitted in any form without the prior
written consent of VEE GEE Scientic LLC.
©2019 VEE GEE Scientic LLC
Warranty information and a registration card
can be found at the following web address:
www.veegee.com/service_support

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Thank you for purchasing this VEE GEE Polarimeter. With the user in mind, VEE GEE Polarimeters are built from
modern designs and, with proper care, this instrument should provide many years of reliable performance. It’s
recommended this manual is read entirely before using the polarimeter for the rst time.
The VEE GEE Model C25L is designed to measure the angle of rotation caused by passing polarized light through
an optically active substance. Measurements can be made with an accuracy of ±0.1 by utilizing a large, ±180°,
full circle Vernier scale. Readings can be interpolated to ±0.05 by an experienced user.
This instrument features a long-life, energy-efcient LED light source with a 589nm lter. The LED light should last
the life of the instrument and therefore requires no regular replacement. The instrument is provided with 100mm
& 200mm sample cells.
Introduction
This polarimeter is a delicate optical instrument and requires an accurately aligned, internal optical path
for proper functioning. Do not shake or jolt the instrument. The impact may damage or cause the optical
components to shift which will result in inaccurate readings.
Do not attempt to open the body of the instrument as there are no user serviceable parts inside.
Please refer to the Service & Support section website for detailed info on returning your instrument for service.
Safety Precautions
Maintenance
Fuse Replacement
This instrument uses a 1A 250V (part number 1200-FS4) fuse which is located on the bottom of the instrument.
1. Turn the power switch off, labeled “0”, and unplug from the power outlet.
2. Remove any sample cells that may be present in the cell chamber and carefully
place the polarimeter on its side.
3. Using a Phillips or slot screwdriver unthread the fuse holder (gure 1) and visually
inspect the liment inside the fuse. If the liment is burnt or the inside of the fuse is
blackened then replace the fuse. Use only the correct fuse. NEVER use a fuse that is
rated higher than what came with the instrument.
4. Re-thread the fuse holder back into the base of the polarimeter.
Cleaning
1. The instrument should not be used in an overly humid environment and should be cleaned with a moist cloth
and mild detergent after use or when liquids have been spilled on it.
2. The polarimeter body can be cleaned using water and light detergent with a soft cloth or tissue. Do not use
harsh chemicals as this may damage the painted surfaces. Be sure to unplug the instrument from the power source
before cleaning. Do not immerse or allow large amounts of water to splash onto the instrument.
3. After each use, clean the sample cell in water and light detergent then wipe dry with a soft cloth or tissue and
allow to air dry.
4. Use only specially formulated lens cleaning uids and tissues to clean the optical components of the instrument.
Failure to do so may result in scratched lens surfaces.
Figure 1

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Polarimeter Components
Eyepiece
Power
Switch
Trap Door
Handle
Sample Chamber
Trap Door
Vernier Scale
Adjustment
Vernier
Scale
Lenses
LED
Illuminator
Included Parts
Upon receiving your VEE GEE Model C25L Polarimeter, check to see that all parts are functioning and focusing
properly and that the following items are supplied with your instrument:
1. Assembled Polarimeter Body (1 ea.)
2. Power Cable (NEMA 5 or Euro Schuko depending on voltage) (1 ea.)
3. 100mm & 200mm Sample Cells (1 ea.)
4. Operation Manual (1 ea.)
Polarimeter
Body
For information about parts, accessories, or service -
contact your VEE GEE dealer or contact VEE GEE Scientic at:
800-423-8842 | veegee.com | [email protected] | [email protected]

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Polarimeter Components
Sample CellSample Cell
Bubble Trap
Main Power
Jack
Eyepiece Focus
Adjustment
Vernier Scale
Windows
Replacement parts can be ordered through your VEE GEE dealer. Contact us for more information.
Item Part No.
Factory replacement 100mm Sample Cell with bubble trap 4600P-SC100
Factory replacement 200mm Sample Cell with bubble trap 4600P-SC200
1A 250V Fuse 1200-FS4
Replacement Parts
For information about parts, accessories, or service -
contact your VEE GEE dealer or contact VEE GEE Scientic at:
800-423-8842 | veegee.com | [email protected] | [email protected]
Cell Chamber

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Setup
Basic Assembly and Eyepiece Focusing
Ensure that the work area is free of dust and dirt.
1. Remove all parts from packaging and place the polarimeter body on a stable
work surface.
2. Insert female end of the main power cord into the power jack located on the rear
of the polarimeter.
3. Insert male end of the main power cord into a suitable power outlet.
4. Flip the power switch to the on position, labeled “|”.
5. The C25L polarimeter utilizes an LED illuminator and therefore requires no warm up period before use.
6. Observe the eld of view through the eyepiece and rotate the eyepiece focus adjustment (gure 2) until the
edges of the round eld of view are sharply focused.
Operation
Glass Sample Cells
The polarimeter comes with 100mm and 200mm glass sample cells. Both utilize bubble traps to prevent air
bubbles from giving inaccurate readings.
1. Obtain a well homogenized sample of the substance to be tested.
2. Unthread and remove the endcap pieces from one end of the sample cell.
3. Pour the substance into the sample cell leaving only a very small amount of air in the cell. Replace the endcap
being careful to tighten only by hand and only until it prevents liquid from leaking out. Over tightening the end cap
will cause stress in the glass which can produce erroneous readings.
4. Open the sample chamber trap door and place the lled sample cell into the chamber with the bubble trap toward
the top, making sure that any air bubbles still in the cell are trapped inside the bubble trap. Close the trap door.
Measuring
This instrument works by passing linear polarized light through an optically active
liquid sample and measuring the degree of rotation that occurs. The reading is then
displayed to the user through a triplex eld of view with the left half-shadow and the
right half-shadow being divided by a center section (gure 3).
Figure 2
Figure 6Figure 4
Figure 3
Figure 5
1. While looking through the eyepiece rotate the Vernier scale adjustment knob (gure 4) until the two half-shadows
are at the same dark intensity as the center section (gure 5).
2. The angle of rotation can now be read on the Vernier scales (gure 6) through the magnifying lenses located
on the eyepiece. A reading of 0° indicates that the sample is optically inactive.

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No light visible in eyepiece: Check if power switch is ipped to the “|” position.
Check if the power cord is attached to the rear of the polarimeter and to a
functioning power supply. Refer to Basic Assembly section.
Check to see if fuse is burnt. Refer to Fuse Replacement section.
Ensure there is nothing blocking the light path in the sample cell chamber.
Field of view is blurry: Make adjustment to eyepiece focusing control. Refer to Basic Setup and
Eyepiece Focusing section.
Ensure that the eyepiece lens is clean and free of oil or dirt.
Obtaining erroneous readings: Check the accuracy and zero the scale if necessary. Refer to Instrument
Accuracy section.
Troubleshooting
Measuring Scale: °Arc
Measuring Range: ±180°
Resolution: 0.1
Accuracy: ±0.1
Optcal Wavelength: 589nm
Sensitivity: Up to 99.9% Light Absorption
Measuring Light Source: LED
Sample Cell Length (max): 200mm
Power Requirements: 110/220VAC, 50/60Hz
Dimensions: 460 x 140 x 330mm
Weight: 5.2kg
Specifications
Operation (continued)
Figure 7
Instrument Accuracy
Your VEE GEE polarimeter was calibrated at the factory during production. Follow the instructions below to check
the accuracy of your instrument and make adjustments if necessary.
1. Ensure the the ambient room temperature of your work area is 20°C (±2°C). Fill
the sample cell with distilled water that is at room temperature. You should get a 0°
reading which indicates that your instrument is reading properly.
2. If the reading is off slightly you can either make manual adjustments to your results
or recalibrate the Vernier Scales. Note: a recalibration should only be performed
by a user that is comfortable making mechanical adjustments to the instrument.
3. With a small Phillips screwdriver (not included) loosen the two set screws (gure 7) located near the Vernier
scale that is reading incorrectly. Do not remove the screws, it is only necessary to slightly loosen them.
4.Use your ngers to push up or pull down the loosened set screws to reposition the inner scale until the 0°
reading is obtained. Hold the scale steady while retightening the adjustment screws. Repeat on the opposite
side Vernier scale if necessary.

Printed in USA No. VGMNL092319-C25L