Vaisala DMT340 - Manual (Page 156)

User's Guide _______________________________________________________________________
154 __________________________________________________________________ M210704EN-G
To ensure the correctness of the adjustment, the reference dewpoint
meter must be calibrated at a recognized laboratory with a known
uncertainty and traceability to national or international standards.
To see when the adjustment was made last, select Adjustment
information (with keypad INFO button in the main view, or with serial
commands ? and CDATE) or check the date from the Device
information. See section Device Information on page 111.
Opening and Closing the Adjustment
Mode
Open the transmitter cover. The buttons needed in the adjustment are on
the left-hand side of the motherboard, see Figure 2 on page 21.
Press the
ADJ
button to enable the adjustment mode. The indicator LED
indicates the adjustment availability.
Table 33 Indicator Led Functions
Indicator Led Function Description
LED off adjustment locked
LED on adjustment available
LED blinking evenly measurement not stabilized
LED blinking with short pulses performing Purge/Autocal
Press the ADJ key again to disable the adjustment mode.
NOTE Fixed pressure compensation of 1013.25 hPa is used when in adjustment
mode. Adjustments should be performed at ambient pressures.