20
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
Vessel height: 12 m, hydrostatic pressure = 12 m x 1000 kg/m
3
x
9.81 m/s
2
= 117.7 kPa = 1.18 bar
Superimposed pressure: 1 bar
Total pressure: 1.18 bar + 1 bar = 2.18 bar
Instrument selection
Nominal measuring range Master: 2.5 bar
Nominal measuring range Slave: 1 bar
Turn Down: 2.5 bar/1.18 bar = 2.1 : 1
Data
Application: Level measurement
Medium: Water
Vessel height: 500 mm, hydrostatic pressure = 0.50 m x 1000 kg/m
3
x
9.81 m/s
2
= 4.9 kPa = 0.049 bar
Superimposed pressure: 350 mbar = 0.35 bar
Total pressure: 0.049 bar + 0.35 bar = 0.399 bar
Instrument selection
Nominal measuring range Master: 0.4 bar
Nominal measuring range Slave: 0.4 bar
Turn Down: 0.4 bar /0.049 bar = 8.2 : 1
Data
Application: Differential pressure measurement
Medium: Gas
Static pressure: 0.8 bar
Differential pressure on orifice: 50 mbar = 0.050 bar
Total pressure: 0.8 bar + 0.05 bar = 0.85 bar
Instrument selection
Nominal measuring range Master: 1 bar
Nominal measuring range Slave: 1 bar
Turn Down: 1 bar/0.050 bar = 20 : 1
The measuring result (level, pressure difference) as well as meas-
ured value Slave (static or superimposed pressure) are output by the
sensor. Depending on the instrument version, output as 4 … 20 mA
signal or digitally via HART, Profibus PA or Foundation Fieldbus.
4.5 Level measurement
The master/slave combination is suitable for level measurement in a
pressurized vessel
Keep the following in mind when setting up the measuring system:
•
Mount the master sensor below the min. level
•
Do not mount the master sensor close to the filling stream or
emptying area
Example - small vessel
Example - orifice in
pipeline
Output measured values
Measurement setup