Adjust Capacitance Measurement - DMT132

DMT132 User Guide

Document code
M211289EN
Revision
B
Language
English (United States)
Product
DMT132
Document type
User guide

Use the CRH command to perform a one-point or two-point correction to the capacitance measurement of the transmitter. This command changes the offset and gain of the measured capacitance, and therefore affects humidity measurement over the entire temperature range.

CAUTION This command should be used only when the HUMICAP® sensor has been replaced, or the measurement has drifted significantly. For normal adjustment, use the RHCAL command instead.
CRH<cr>

When performing a one-point adjustment, you need to place the transmitter in a single humidity reference with RH < 50%. Run the command and enter the exact RH of the reference after the measurement has stabilized. Exit the command by pressing the ESC key before proceeding to the second point (see the first example below).

For two-point adjustment, the first point requires a RH < 50% humidity reference, the second point must be RH > 50%. There must also be at least 30 percentage points of difference between the references. The measurement reading for the second point will appear when this requirement is met.

Example: one-point adjustment

>crh
RH:      11.41200712 Ref1 ? 11.3
Press any key when ready
OK
>

Example: two-point adjustment

>crh
RH:      11.41200712 Ref1 ? 11.3
Press any key when ready
RH:      74.72910210 Ref2 ? 75
OK
>