Vaisala DMT132 - Manual (Page 58)

USER'S GUIDE____________________________________________________________________
56 __________________________________________________________________ M211289EN-A
1. Disconnect the cable from connector I of the DMT132 (if
connected).
2. Connect the USB cable to connector II on the DMT132, and to a
USB port on your PC.
3. Start a terminal application and set the service port connection
settings (19200 8 N 1). Remember to check which COM port the
USB cable is using.
4. Verify that the connection works by giving the ? command:
>?
If the transmitter does not respond with device information:
- Check your serial line settings and cable connections
- Reconnect the USB cable, restart the terminal application, and
try again.
5. When your serial connection is working, use the L command to see
the current user adjustment parameters. Write down the RH offset
and gain values so you can restore them manually using the LI
command, if necessary.
>l
6. Use the ERRS command to see that no errors are active:
>errs
7. 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.
8. 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 RHCAL 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.
>rhcal
RH: 10.840536 Ref1 ?
10. Wait for 20 ... 40 minutes for the reading to stabilize. Press ENTER
without typing anything to update the value shown by the RHCAL
command.
RH: 10.890510 Ref1 ?
RH: 10.920197 Ref1 ?
RH: 10.930460 Ref1 ?