Vaisala HMT330 - Manual (Page 105)

Chapter 4 _________________________________________________________________ Operation
VAISALA _______________________________________________________________________ 103
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. 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
>