Vaisala DMT346 - Manual (Page 155)

Chapter 7 ___________________________________________________ Calibration and Adjustment
VAISALA _______________________________________________________________________ 155
One-Point Dewpoint Adjustment
One-Point Dewpoint Adjustment Using
Display/Keypad
NOTE This is a highly critical adjustment, to be performed only in laboratory
conditions.
Preferably use the display/keypad interface to perform one-point
dewpoint T
d/f
adjustment. Before proceeding with the Td/f adjustment
you must perform the RH adjustment. For DMT345/346, the reference
dewpoint must be below -25 °C (-13 °F) and temperature must be below
40 °C (104 °F).
NOTE This adjustment is valid only if the measurement or process is in the
lower end of the measurement range (in very dry). See Specifications on
page 161.
When adjusting the dewpoint, refer to the following instructions:
1. Press the ADJ button on the motherboard to open the
ADJUSTMENT MENU.
2.
Press the ► arrow button to select Adjust T
d
measurement.
3. Select by pressing 1-point T
d
adjustment. Press START to start
adjusting.
4. Leave the sensor to stabilize for at least one (1) hour. Follow the
instructions on the display.
0706-043
Figure 75 Following Stabilization
0706-044
Figure 76 Proceeding with T
d/f
Adjustment