METER GROUP AquaLab 4TE - Multipoint Calibration (TEV Only)

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SERVICE
4.1.3 MULTIPOINT CALIBRATION (TEV ONLY)
The capacitance sensor used for measuring the water activity of materials with volatiles
(AQUALAB 4TEV models only) is a secondary method for measuring water activity and
may require a slope change to the calibration in addition to a linear offset. This is the case
when the offset in capacitance mode is different at high water activities than low water
activities.
The 0.25, 0.50, 0.76, and 0.92 a
w
unsaturated salt standards are needed to proceed with
multipoint calibration.
1. Navigate to the Configuration tab.
For the AQUALAB 4TEV, make sure to select the capacitance sensor before beginning the
multipoint calibration.
2. Select Calibration from the Conguration tab (Figure63).
Figure63 Capacitance sensor calibration screen
3. Highlight Type and select ENTER to toggle to Multipoint.
4. Select Start.
Prompts will instruct the user to insert a fresh standard and seal the chamber
(Figure64).
Figure64 Prompt to insert fresh standard
5. Empty the whole vial of 0.25 a
w
standard solution into a sample cup.
6. Ensure the rim and outside of the cup are clean.