9
ORA_90BE-BA-e-1510
7.2
Measuring procedure
Make sure your hands are dry before handling the refractometer.
Open the prism cover [1] and use the supplied pipette [8] to apply a few drops
of the sample liquid [8] onto the prism surface [2], then close the prism cover
[1]. Spread the liquid evenly by pressing down on the prism cover [1].
Hold the device horizontally and wait about 30 seconds (for optimal tempera-
ture equalisation between the sample and device).
View the measurement scale through the eyepiece [6]. Point the prism surface
[2] of the refractometer at a bright light source while doing this.
The light falling on the prism can be changed using a rotating flap on the un-
derside of the prism.
Rotate the adjustment ring [6] on the eyepiece [6] to adjust the focus.
The boundary line will move on the measurement scale depending on the
concentration. This bright/dark boundary line shows the result directly on the
scale.
The measuring instrument has three measuring ranges. Please use the
measuring range adjusting wheel on the underside of the casing to switch
measuring ranges.
The light/dark boundary can be brought into sharp focus using the dispersion
adjusting ring [6]. This is useful for low liquid concentrations.
If the temperature deviates from +20 °C, correct the measured result using the
corresponding value from the temperature correction table [13].
Carefully clean the supplied pipette [8] and the refractometer after carrying out
the measurement.
Important!
After every measurement, use a lint-free, absorbent cloth to remove the fluids from
the prism surface [2] and prism cover [1]. Then carefully clean the prism and prism
cover using a cloth moistened with water or if necessary alcohol, and dry both parts
using a soft, dry and lint-free cloth. Avoid rubbing the prism [2].
Summary of Contents for ORA 1 RE
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