1. Put the refractometer on a platform with full light, avoid direct sunlight, install a thermometer, and place the instrument at least half an hour at room temperature.
2, if we need to measure the prescribed temperature, we can connect the prism's constant temperature water interface to the constant temperature water bath of the temperature, circulate for at least half an hour, or put it in a thermostat for at least 1 hours.
3, the mirror and the lower light instrument prism toward the light source, a lens barrel near the operator, make a proper point of view, alignment of mirrors, the brightest light in the field of vision, if in the evening or insufficient light or dark color in the interior, determination of seized goods, the round window prism the open, to increase light intensity. Open the reading window next to the reading mirror, and the reader should be on the left of the operator.
4, unscrew the upper and lower prisms, wipe the mirror with dipping paper and wipe up the upper and lower prisms with a little ether. Then drop 1-2 drops of pure water on the lower prism (lower prism is rough surface), close the upper and lower prisms, and tighten the prism wrench.
5. Instrument correction. The scale knob refractometer the lower left, the reading in the vicinity of 1.3330 mirror angle adjustment instrument or on the lower part of the transparent prism at light intensity at the same time, next to the right view of the dispersion compensation barrel rotating knob, so that the vision in the rainbow disappeared, a distinct line of demarcation, if necessary, and then adjust the mirror angle on the bright light or prism strength, make clear vision. Then the scale knob of the scale is rotated to make the boundary line in the field of vision located just at the cross line and read the scale of the scale. After the measurement, it is required to turn the scale knob again, and repeat the readings 2 times, taking the average of the 3 readings, that is, the refractive index of pure water at that temperature. The corrected error of the refractometer is calculated, or the correction screw above the visual field is adjusted according to the regulation, so that the field of vision is exactly the specified reading.
6, the upper and the lower prism opened, with lens cleaning paper clean water, drying, adding 1-2 drops in the test solution on the prism prism, will close, tighten the prism wrench, according to the fifth determination method for the determination of water samples, rotating the scale knob, the readings in samples of refractive index nearby, and then rotating compensator knob to make view terminator is located at the cross point, so repeated 3 times, the average values of the 3 readings
7, open reading tube small mirrors, proper lighting, remember reading and temperature on the scale is the temperature when the refractive inspection rate, the left line containing sucrose percentage readings, right index reading, reading and correction for refraction test solution rate
8, measured as samples for aqueous solution, should immediately use absorbent cotton to absorb the test liquid and then drop distilled water to the prism, and then cotton dry, repeated washing 3 times, finally wiping paper or cotton to gently wipe clean as Abbe refractometer, seized goods for oil substances, should be the prism according to the law to wipe clean with xylene or ether absorbent cotton