Liquid Level Measurement; Open Tank Level Measurement - GE Hart Druck RTX 1000H Series User Manual

RTX 1000H series user manual

3.8 Liquid Level Measurement

Gauge pressure transmitters can be used to measure liquid level in an open or
vented tank by measuring the hydrostatic pressure head. The head pressure
can be calculated by multiplying the liquid height above the transmitter
diaphragm by the specific gravity of the liquid.
The tank's volume and shape does not affect the head pressure. If the
transmitter is mounted below the zero point (minimum level) of the measured
range, zero suppression will be required.
sg = 1.1
5000 mm
1000 mm
Calculations
Min. level = (1000 x 1.1) mmH
= 1100 mmH
Max level = ([1000 + 5000] x 1.1) mmH
= (6000 x 1.1) mmH
= 6600 mmH
Range = 1100 to 6600 mmH
(Span = 5500 mmH
K0297 Issue 2
maximum level
minimum level
Figure 3-4: Open tank level measurement
O
2
O
2
O
2
O
2
O
2
O)
2
20
mA
4
0
O
2
3-6
zero
suppression
1100
mmH O
2
6600