Optical refractometer is a precision instrument with high precision and reliability, especially suitable for measuring the freezing point of glycol solution as antifreeze and glass water and the weight of electrolyte.

1. Point the front end of the refractometer to the bright spot, and adjust the sight glass adjustment device until the scale line is the clearest.

2. Zero point adjustment: Open the front cover and drop 1 to 2 drops of distilled water on the surface of the prism. Close and lightly press the front cover, and then adjust the calibration knob so that the light and dark dividing line of the water line is on the bottom line.

3. Open the front cover, use a soft lint cloth to dry the water on the surface of the prism and the cover plate, and then drop 1 to 2 drops of the liquid to be tested on the surface of the prism, close and gently press the cover plate, on the scale corresponding to the The dividing line between light and dark is even if the freezing point of the tested liquid or the percentage of electrolyte is heavier.

4. After the measurement, clean the attachments on the spiritual realm and the cover with a wet gauze, and keep it properly after it dries.