Vaisala DMT346 - Manual (Page 100)

User's Guide _______________________________________________________________________
100 __________________________________________________________________ M210762EN-G
UNIT
Use the UNIT command to select metric or non-metric output units, and
change the unit for the H2O quantity:
UNIT [x]
where
x = Unit system to be used. Options are:
M (metric units)
N (non-metric units)
UNIT H2O [y]
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 to either
metric or non-metric units. When you want to output both metric and
non-metric units simultaneously on the display, select the display units
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. If you are using mixing ratio as an
output quantity, it is recommended that you make the pressure
compensation setting.
Note that conversions from mmHg and inHg are defined at 0°C and for
mmH
2
O and inH
2
O at 4°C.