Open tank Level measurement Principle

The simplest application is the fluid level in an open tank. The figure shows a typical open tank level measurement installation using a pressure capsule transmitter.

If the tank is open to atmosphere, the high pressure side of the level transmitter will be connected to the base of the tank while the low-pressure side will be vented to atmosphere.

In this manner, the level transmitter acts as a simple pressure transmitter.

Phigh = Patm + S.H
Plow=Patm
Differential pressure, ΔP = Phigh – Plow = S.H

If the tank is open to atmosphere, the high pressure side of the level transmitter will be connected to the base of the tank while the low-pressure side will be vented to atmosphere. DP transmitter is installed in open tank for the measurement of level of high pressure leg and DP transmitter is connected with bottom of tank for measurement of low pressure leg which is open in atmosphere.