Sper Scientific 300056 Digital Refractometer Custom 1 Scale - Manual (Page 5)

- 8 -
• Do not drop or shake the unit.
• Use the protective carrying case to
prevent physical damage.
Erratic Readings
If the readings are significantly above or
below the expected results, consider the
following:
•
Sample contains more than one dissolved
solid. For example, if the sample contains
both salt and sugar, a Brix refractometer
will not display the true sugar content
because the salt content will skew the brix
measurement.
• When diluting samples, be sure to use a
pure solution such as distilled water.
• Sample contains suspended solids. Filter
and thoroughly mix the sample before
testing.
• Perform a calibration.
• Replace the battery.
•
Outside light can cause erratic readings,
make sure to close the COVER on the
PRISM during measurement.
•
After about 3000 tests, turn the unit off for
5 to 10 minutes to rest the battery.
- 5 -
3. CALIBRATION
Calibration should be performed daily before
sample testing begins. For best results,
perform the calibration in a controlled
environment of 68°F (20°C).
• Allow the refractometer and the distilled
water to acclimate to the ambient
environment.
•
Clean the PRISM (3) before and after
every use.
•
Drop at least 1.0 ml of distilled water (0.0)
onto the PRISM (3).
•
Close the PRISM COVER (2).
•
Press the READ (9) button to turn on the
refractometer.
• Press the ZERO (10) button for 3 seconds
to enter calibration mode.
• "CAL" flashes on the display. There will
be a red flash in the PRISM (3).
• The calibration is complete after "End" is
displayed.