1.Cover plate
2.Knob
3.Adjusting ring
4.Entrance light prism
5.Eyepiece

DESCRIPTION
Model RHB0-90 has three scale to cover the range of 0 to 90%, scale one is 0 to 42%, scale two is 42 to 71%, scale three is 71 to 90%. The wide range substances with unknown concentrations.

METHOD OF OPERATION
1. Aim the front end of the refractometer to the direction of bright light, and adjust the adjusting ring of diopter 5 until the reticle can be seen clearly.
2. Adjustment of null
The null of this instrument has been adjusted before it is out of factory.
3. Open the entrance light prism, clean the surface of prism by soft cotton flannel, drop 1~2 drops of solution to be measured. Close the entrance light prism, press it lightly, then read the corresponding scale of light and dark boundary, the reading is the brix of measured solution.
4. If the light is not sufficient, you could rotate and adjust 1.
5. The model has three scales, you could get them by rotating 2.
6. When measure solution of high concentration, there would be chromatism in the view, you could reduce it by rotating 3.
7. After measurement, clean away the adherend on the surface of prism and cover plate by moist gauze.

ATTENTIONS AND MAINTENANCE
1. After usage, don’t use water to wash the instrument, so as to avoid water entering into the pipe of the instrument.
2. As it is a kind of precision optical instrument, you should hand it gently and take good care of it. Don’t touch and scratch the optical surfaces. It should be kept in the environment of dry, clean and non-corrosiveness air, so as to prevent the surface of it turning mouldy and foggy. Please avoid strong shock during transportation.
3. The reference of temperature is 20℃. In operation, the temperature compensation should be made according to the table.

ACCESSORY
1.Suction tube 1
2.Screw driver 1