Vaisala PTU300 - Manual (Page 113)

Chapter 4 _________________________________________________________________ Operation
VAISALA _______________________________________________________________________ 111
PSTAB
Use the PSTAB command to define the pressure stability indicator
reflecting maximum allowed pressure difference between two successive
averaged measurements. The user also has to define the FORM
command to include the "OK" stability indicator field. The factory
setting for the stability indicator level is 0.5 hPa.
Example:
>pstab
Stab. indicator: OFF ? on
Max P change : 0.5 ? 1.0
PDMAX [x]
where
x = Pressure reading
The PDMAX [x] command is used to define the maximum pressure
difference between the pressure readings from two pressure transducers
(P1 and P2). If the defined value is exceeded, the relevant digit in the
ERR field will change from 0 to 1.
Crucial conditions for an acceptable measurement are:
Two transducers: P high - P low = Pd max limit/less than Pd max limit
The factory setting for Pdmax is 1.0 hPa.
Example of setting the limit to 0.5 hPa:
>pdmax
Max P diff. : 1.00 ? 0.5
Pdmax limit works as follows:
>form 4.1 p1 " " p2 " " p " " u3 " " ERR #r#n
OK
Example: Maximum pressure difference is within the limit
>send
1034.2 1034.4 1034.3 hPa 0000
Example: Maximum pressure difference exceeds the limit
>send
1034.2 1035.4 ****** hPa 1000
Use the ERRS command to analyze problems.