METHOD OF OPERATION

1.Prepare: Aim the front end of the refractometer in the direction of a bright light, and adjust the adjusting ring of diopter(5) until the reticle can be seen clearly.

2.Calibration: Open the cover plate(2), drop one drop of calibration solution on the prism(1), rotate and adjust the calibration screw(3) to make the light/blue boundary coincide with reference line 1.333.

3.Measurement:Open the cover plate(2),clean the surface of prism with a piece of soft cotton flannel, Drop 1~2 drops of the solution to be measured. Close the cover plate, and press it lightly, then read the corresponding scale of light and dark boundary. The reading is the refractive index of the measured solution.

4.After measurement, clean the surface of prism and cover plate with moist gauze, and it should be stored carefully.