Vaisala HMW90 - Manual (Page 73)

Chapter 5 _______________________________________________________________ Maintenance
VAISALA ________________________________________________________________________ 71
Adjustment Using a PC
For more detailed instructions on using the Vaisala USB cable and a
terminal application, see section Connecting With a PC on page 38.
For a description of the serial commands, see section Calibration and
Adjustment Commands on page 58.
1. Connect the HMW90 series transmitter to your PC using the
Vaisala USB cable (order code 219690).
2. Start a terminal application and open a new session to the service
port of the transmitter. The serial line settings are 19200, N, 8, 1.
3. Before changing the adjustment, issue the following commands to
see the transmitter’s current adjustment information:
pass 9000
crh
ct
ctext
cdate
4. Place the entire transmitter in the desired reference condition and
allow the measurement to stabilize. Follow the stabilization from
the serial line (output from the R command) or the display.
5. You can now use the CRH and CT commands to adjust the
transmitter’s RH and T measurement. Refer to the command
descriptions for the available options.
6. After performing the adjustment, verify from the serial line or the
display that the measurement has been corrected.
7. After completing the adjustments, you can enter a descriptive text
string in the transmitter’s memory using the CTEXT command,
and note the adjustment date using the CDATE command.