Siemens SITRANS P DS III - Page 55

Installing / mounting
4.5 "Remote seal" installation
SITRANS P DS III with PROFIBUS PA
Operating Instructions, 06/2013, A5E00053276-07
55
Installation type for gauge pressure and level measurements (open containers)
Installation type A
Pressure transmitter above the
measuring point
Start of scale value:
p
MA
= ρ
FL
* g * H
U
+ ρ
oil
* g * H
1
Full
-scale value:
p
ME
= ρ
FL
* g * H
O
+ ρ
oil
* g * H
1
Installation type B
Pressure transmitter below the
measuring point
Start of scale value:
p
MA
= ρ
FL
* g * H
U
- ρ
oil
* g * H
1
Full
-scale value:
p
ME
= ρ
FL
* g * H
O
- ρ
oil
* g * H
1
H
1
≤ 7 m (23 ft); with halocarbon oil as the filling liquid, only H
1
≤ 4 m(13.1 ft)
Key
p
MA
Start of scale value
p
ME
Full-scale value
ρ
FL
Density of the process medium in the container
ρ
oil
Density of the filling oil in the capillary line of the remote seal
g
Acceleration due to gravity
H
U
Lower filling level
H
O
Upper filling level
H
1
Distance between the container flange and the pressure transmitter
For absolute pressure measurements (vacuum), install the measuring device at least at the
height of the remote seal or below it (see installation types C).