Vaisala HMP230 - Manual (Page 104)

HMP230 SERIES
Appendix 1: Serial commands
M210225en-B
98
FILT Setting the averaging time
Disconnect the security lock jumper!
FILT nnnn
nnnn = averaging time (0 - 1024 seconds)
This command is used to set and inspect the averaging time during which the
individual measurement samples are integrated to get an averaged reading.
The time can be set in seconds within the range of 0 - 1024 (0 = no averaging
time).
For example:
>FILT
Filter (S):
0 ? 1024
>
>FILT 100
Filter (S):
100
>
PRES Setting the pressure for pressure compensation of the
HUMICAP
   
sensor and for mixing ratio, wet bulb
temperature and enthalpy calculations
PRES pppp.pp
pppp.pp = pressure (hPa)
The atmospheric pressure has an effect on mixing ratio, wet bulb temperature
and enthalpy. Therefore, accurate calculations can be achieved only when the
ambient pressure is taken into consideration. The pressure is used for pressure
compensation of the HUMICAP

sensor in order to ensure the best possible
measurement accuracy. If the process pressure differs from normal ambient
pressure, the value has to be entered in the transmitter memory when using the
transmitters HMP234 or HMP238. The pressure to be entered is the absolute
pressure in hPa (or mbar) (for pressure unit conversion, see Appendix 10).
NOTE
The pressure compensation takes place only with the
security lock jumper connected. If the security lock
jumper is not connected, the pressure compensation is
performed with the value 1013.25 hPa.