Siemens SITRANS P DS III - Connection of the Negative Pressure Line

Installing / mounting
4.4 "Level" installation
SITRANS P DS III with PROFIBUS PA
50 Operating Instructions, 06/2013, A5E00053276-07
4.4.3
Connection of the negative pressure line
Assembly on an open container
A line is not required when taking measurements in an open container since the negative
chamber is connected with the atmosphere.
Ensure that no dirt enters the open connection ports, for example by using connection
screws with a 7MF4997-1CP bleed valve.
Measurement assembly on an open container
Formula:
Start of scale value: p
MA
= ρ · g · h
U
Full
-scale value: p
ME
= ρ · g · h
O
h
U
Lower filling level
Δp
MA
Start of scale value
h
O
Upper filling level
Δp
ME
Full-scale value
p
Pressure
ρ
Density of the measured medium in
the container
g
Acceleration due to gravity