Vaisala PTB330 - Manual (Page 80)

USER'S GUIDE____________________________________________________________________
78 __________________________________________________________________ M210855EN-D
DPMAX
The serial line command DPMAX shows or sets the maximum
permissible difference pressure allowed between barometer modules.
The command is only available if more than one barometer module
has been installed.
DPMAX [x] [y] [?]
where:
x = Pressure
y = Unit
Example:
>dpmax 0.2
Max. diff. : 0.20 hPa
>
If the defined value is exceeded, the relevant digits in the ERR field
(see FORM command) change from 0 to 1, and the corresponding
pressure measurement(s) are no longer included in the average
pressure reading.
Vaisala recommends using the ERR field as part of the FORM
command definition if there are two or three pressure transducers in a
PTB330 series digital barometer.
The following basic cases may occur for barometers with two or three
pressure transducers (only the differences found between the readings
from the pressure transducers are important):
P high
P high ≤ DPMAX ?
Two transducers: ≤ DPMAX ? Three transducers: P middle
P low ≤ DPMAX ?
P low
For an acceptable measurement crucial conditions are:
- two transducers: P high - P low
 DPMAX
- three transducers:
P high - P middle
 DPMAX and P middle - P low  DPMAX.
The factory setting for DPMAX is 1 hPa.