Vaisala DMT132 User Manual

Page 63

Chapter 5 ______________________________________________________________ Maintenance

VAISALA _______________________________________________________________________ 61

When your serial connection is working, use the L command to see
the current user adjustment parameters. Write down the Cp offset
and gain values so you can restore them manually using the LI
command, if necessary.

6. Use

the

ERRS

command to see that no errors are active:

>errs

Install the HMK15 calibrator fitting over the LiCl salt chamber of
the humidity calibrator (11 %RH). Make sure it sits tightly over the
salt chamber.

Insert the DMT132 into the chamber. Do not remove the filter.
Make sure all unused holes are plugged and the transmitter is
installed tightly on the thread.

9. Give

the

CRH

command. The output from the command shows the

currently measured RH value, and prompts you to enter the value
of the first reference (Ref1). This is the reference on the dry end,
which produces the offset correction for the measurement.

>crh
RH: 11.39800112 Ref1 ?

10. Wait for 20 ... 40 minutes for the reading to stabilize. Press ENTER

without typing anything to update the value shown by the CRH
command.

RH: 11.39800112 Ref1 ?
RH: 11.38377201 Ref1 ?
RH: 11.37988329 Ref1 ?

11. When the measurement shown by CRH is stable, you can either

apply the correction or exit the procedure:

- To apply the correction, press ENTER one last time to update

the value, type 11 and press ENTER again (assuming you are
using the HMK15 and the LiCl salt).

- To exit the CRH command without adjusting the measurement,

press the ESC key and exit this procedure.