AquaLab 4 Series User Manual

AquaLab 7 VERIFICATION AND CALIBRATION
water activity you plan to test. For example, if you plan to test
for water activity readings ranging between 0.713 and 0.621 you
should use the 8.57 mol/kg LiCl (0.50 a
w
) standard for your
first verification and the 6.00 mol/kg, NaCl (0.76 a
w
) for the
second verification.
6. Prepare a sample cup of the second verification standard and
make two readings. The second water activity reading for the
second verification standard should be within ±0.003 a
w
for
the dew point and ±0.015 for the capacitance sensors.
7. If either of the verification standards is not correct, it is prob-
ably due to contamination of the sensor chamber. For cleaning
instructions, see Section 6. After cleaning, repeat verification
from step two.
8. If you are consistently getting readings outside the water activ-
ity of your first verification standard by more than ±0.003 a
w
for dew point and ±0.015 for capacitance, a linear offset has
probably occurred. In this case, adjust the reading to match
the correct verification standard value as outlined in the next
section.
39

AquaLab 4 Series Specifications

General

Brand	AquaLab
Model	4 Series
Category	Measuring Instruments
Language	English