Calibration - PCE Instruments PCE-ALK Manual

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Calibration

Before using the refractometer for the first time, you have to perform a calibration. We also recommend
calibrating the device on a regular basis.
The refractometer has an automatic temperature compensation which compensates for fluctuations in the
environmental temperature. However, during calibration, the environmental temperature has to be +20 °C
to assure accurate measurement results later.
Use distilled water for calibration and follow these steps:
1. Open the daylight plate and use the pipette to place a few drops of distilled water on the prism.
Close the daylight plate and make sure that the prism is evenly covered with liquid and free from
any air bubbles.
Let the water rest on the prism for approximately 30 seconds for temperature equalization.
2. Hold the prism in the direction of a light source and look through the eyepiece.
Now you can see the indicator scale. If necessary, use the focus adjustment to get a sharp
image.
3. To calibrate the refractometer, use a screw driver and adjust the calibration screw, so that the
white and the blue area meet right at the "0" mark on the scale (see picture below).
The device is now calibrated.
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