Aim the front end of the refractometer in the direction of bright light and set the
adjusting ring of dioptre until the scale can be seen clearly. Open the cover plate, put
one or two drops of distilled water on the prism. Close the cover plate and press it
lightly. Then adjust the setting screw to make the light and dark limit coincide with
the ZERO line. If the instrument is ATC (with Automatic Temperature Compensation
system), the room temperature must be 20°C whenever the instrument is
recalibrated. Once calibrated, shifts in ambient temperature with an acceptable
range (between 10°C - 30°C) should not affect accuracy.
Utilisation
After taking the measurement, clean the remaining liquid on the surface of the prism
and cover the plate with a damp gauze. After drying, store the instrument carefully.
Temperature compensation
The reference temperature is 20°C (68°F). Refractometers with “ATC” have an
automatic temperature compensation.
If you need to make temperature corrections this can be done using the table below.
Precaution
Avoid washing this instrument in water. Handle gently and avoid touching the optical
surfaces. The refractometer must be stored in a dry, clean and non-corrosive
environment. Avoid strong shocks.
Accessories
Suction tube / Screwdriver / Case / Cleaning Cloth
Corrections for temperature applicable to density hydrometers standardized at 20°C
(68°F) or 15°C (59°F):
These corrections when applied to the hydrometer reading at t°C give the density of the liquid
in kg/m³ or g/ml at t°C.
