Vaisala DMT340 - Manual (Page 108)

User's Guide _______________________________________________________________________
106 __________________________________________________________________ M210704EN-G
where
y = Unit to be used for H20. Options are:
PPMV (parts per million by volume)
PPMW (parts per million by weight)
NOTE This command changes both the serial output and display units. When
you want to output both metric and non-metric units simultaneously on
the display, select the display units later by using the display/keypad.
Examples:
>unit m
Output units : metric
>unit h2o ppmv
H2O units : ppmV
>
Use the MOL/MOLI command to view/set mole weight parameter that
will be used in calculating H
2
O ppm
w.
Pressure Compensation Setting
The pressure has an effect on humidity calculations and accuracy.
Therefore, accurate calculations can be achieved only when the process
pressure is taken into consideration.
Note that conversions from mmHg and inHg are defined at 0°C and for
mmH
2
O and inH
2
O at 4°C.
NOTE Pressure compensation is intended to be used in normal air only. When
measuring in other gases, please contact Vaisala for further information.
NOTE Fixed pressure compensation value of 1013.25 hPa is used when in
adjustment mode.
Using Display/Keypad
Use display/keypad to set the pressure compensation. To select the
pressure unit using display/keypad see section Changing the Quantities
and Units on page 103.
1. Press any of the arrow buttons to open the Main Menu.
2. Select Measuring
and press the ►arrow button to confirm your
selection.