
9.2.4.3
Volume and mass flow measurements
The following characteristic curves are available for volume and mass flow measurements:
● Hold at 0, square root (VSOFF, for volume or MSOFF, for mass flow)
The loop current is 4 mA up to the application point (low flow cut-off (Page 132)). Starting
from the application point, scaling occurs according to the square root:
$SSOLFDWLRQSRLQW
6H
WWL
QJU
DQ
JH
IR
UD
SS
OLF
DW
LR
QS
RL
QW
EDU
;
Y
Loop current or flow
X
Set measuring span
● Linear, square root (VSLN, for volume or MSLN, formass flow)
The loop current has a linear relationship with the differential pressure up to the application
point (Page 119). Starting from the application point, scaling occurs according to the square
root:
$SSOLFDWLRQSRLQW
OLQHDU
6H
WWL
QJU
DQ
JH
IR
UD
SS
OLF
DW
LR
QS
RL
QW
EDU
;
Y
Loop current or flow
X
Set measuring span
Parameter assignment
9.2 Parameter assignment over device with display
SITRANS P320/P420 with 4 to 20 mA/HART
Operating Instructions, 11/2019, A5E44852162-AC
115