VEE GEE C10 - Refractometer Calibration; Liquid Calibration Procedure; Solids Calibration Procedure; Connecting a Circulator

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It is considered good laboratory practice to calibrate this refractometer using the liquids calibration procedure
on a daily basis. Listed below also is a solids calibration procedure that can be performed occasionally if desired
or as a part of your organization’s SOP.
Liquid Calibration
1. Unlock and open the secondary prism.
2. Place 2-3 drops of distilled water on the primary prism.
3. Close and lock the secondary prism. Be sure the liquid covers the prism surface completely, without any gaps
or bubbles.
4. Rotate the light collector toward a bright ambient light to provide the best illumination for the display.
5. Open the light cover.
6. Close the prism reector.
7. While looking through the eyepiece rotate it in either direction to focus on the crosshair inside.
8. Turn the scale adjustment knob to nd the position of the halftone boundary line.
9. Turn the dispersion adjustment knob to remove color from (and sharpen the image of) the boundary line.
10. Turn the scale adjustment knob until the boundary line intersects with the crosshair.
11. Distilled water should read 1.3330 nD or Brix 0.0%. If it does not, use the included screwdriver to adjust the
calibration screw to move the line to the correct position.
Calibration
The temperature of the prism assembly can be regulated with the use of a constant temperature circulator. This
will improve the accuracy of the refractometer. Using a circulator is not absolutely necessary though.
1. Connect the circulator to the four circulator ports using rubber hose for both the primary and secondary prisms.
A thermometer is provided the read the temperature of the prism assembly.
2. To connect the thermometer, insert and thread the thermocoupler into the thermometer port until fully sealed.
DO NOT OVERTIGHTEN.
3. Open the battery door on the back of the thermometer body and insert both LR44 button cell batteries. The
diagram on the battery door indicates the correct polarity. Replace the battery door.
3. Place the thermometer onto the thermometer mount. The thermometer will be held in place by magnets within
the thermometer body.
Connecting A Circulator
Solids Calibration
1. Unlock and open the secondary prism.
2. Place one drop of contact liquid (1-bromonaphthalene or similar with higher RI than the glass standard) on
the primary prism. The contact liquid is sold separately, contact our customer service department or your VEE
GEE dealer for more information.
3. Place the glass standard on the primary prism, polished side down.
4. Rotate the light collector toward a bright ambient light to provide the best illumination for the display.
5. Close the prism reector.
6. While looking through the eyepiece rotate it in either direction to focus on the crosshair inside.
7. While looking at the internal scale turn the scale adjustment knob to the nD value etched on the glass standard.
8. Turn the dispersion adjustment knob to remove color from (and sharpen the image of) the boundary line.
9. The boundary line should lie in the center of the crosshair. If it does not, use the included screwdriver to adjust
the calibration screw to bring the line into the correct position.