Vaisala DM500 - Manual (Page 68)

User's Guide ______________________________________________________________________
66 __________________________________________________________________ M210205EN-D
If the salt detection sees salt on the sensor (message on the display),
please clean the sensor carefully, see page 113. The salt warning
message is shown when the measured value decreases below 80 % of
the salt detection limit. It is not recommended to use serial commands
during the salt detection. Salt detection interrupts the dewpoint
measurement for approximately one minute.
The salt detection function is enabled as follows:
1. Open MENU : press .
2. Select ► Measuring , press .
3. Select ► Self diagnostics , press .
4. Select ► Salt detection .
5. To enable the automatic sensing, select Autodetect interval , press
SET and give the salt sensing interval (1...99 h) by using the
numeric buttons.
6. Press OK .
7. Carry out this step only if you want to determine the clean
sensor value after cleaning.
Select
Clean sensor value , press DETERMINE . In this stage, the
system measures the salt detection limit (clean reference). To
disable the automatic sensing, press
OFF .
8. To start the manual salt sensing test, select Manual salt sensing
and press
START .
9. Press EXIT to return to the main view.
Sensor Circuit Check
During the sensor circuit check the sensor is heated up and the
propagation of the RF-signal through the circuit is checked. If the
system is not operating as expected the error message is shown, see
page 115, Error Messages. The sensor circuit check also re-calculates
the transmission for a dry sensor, thus performing contamination
compensation.
Sensor circuit check is performed automatically each time when the
measuring is started. During the measuring, the periodical checking is
not done (default) unless the automatic sensor circuit check is turned
on by setting the interval. In case there is a need for checking the
operation of the sensor periodically, or if automatic dry-out cycle for