Siemens SITRANS P DS III Operating Instructions Manual page 52

Installing / mounting
4.4 "Level" installation
When taking measurements in a closed container with strong condensate formation, you
must fill the negative pressure line (mostly with the condensate of the measured medium)
and install a condensate pot. You can cut off the device using the dual pneumatic block
7MF9001-2.
Measurement assembly on a closed container (strong
condensate formation)
h
U
h
O
h
V
p
The process connection on the negative side is a female thread
Lay the line for the negative pressure using a seamless steel tube 12 mm x 1.5 mm.
52
Lower filling level
Upper filling level
Gland distance
Pressure
Formula:
Start-of-scale value:
Δp = g · (h
MA
Full-scale value:
Δp = g · (h
MA
Δp Start of scale value
MA
Δp Full-scale value
ME
ρ Density of the measured medium in
the container
ρ ' Density of fluid in the negative
pressure line corresponds to the
prevailing temperature there
g Acceleration due to gravity
/ -18 NPT or an oval flange.
1
4
SITRANS P DS III with PROFIBUS PA
Operating Instructions, 06/2013, A5E00053276-07
· ρ- h · ρ')
U V
· ρ- h · ρ')
O V