26
SySTEM
Figure 31 Custom mode screen
Select
SAVE to update and exit. Select CANCEL to exit without updating. The Mode
screen now appears with the updated custom settings appearing at the top of the
screen.
If autosave is turned on (default), all test readings will save to the instrument memory,
but only the final reading will remain on the Measurement screen.
Low-Emitting mode gives the option of speeding up test time by adjusting the
equilibrium trigger value (
). This mode is for samples that are slow to
equilibrate such as vegetable oils, high fat samples, and high viscosity samples.
Figure 32 Low-Emitting mode
AQUALAB TDL determines vapor equilibrium at the end of a test by comparing sequential
water activity values, looking for a trigger value difference <0.0005
a
w
. This value can be
adjusted to any value between 0.0003 and 0.0030
a
w
. Increasing the trigger value causes
a subsequent reduction in instrument accuracy and precision but results in a shorter
test time. This mode is for samples that are slow to equilibrate, such as vegetable
oils, high-fat samples, and high-viscosity samples. In these types of cases, the loss
in performance may be acceptable in order to speed up the analysis time. Use a high
trigger value only after careful consideration of the impact on test results.
•
Date. Select to set the date in the instrument. Use RIGHT and LEFT to change between
the month, day, and year categories and
UP and DOWN to change the individual values
The date is recorded with each water activity reading.
