Emerson Process Management 2051 manual Rosemount, Reference Manual, 00809-0200-4101,Rev AA July

Reference Manual

00809-0200-4101, Rev AA July 2008

Rosemount 2051

Bubbler System in Open Vessel

A bubbler system that has a top-mounted pressure transmitter can be used in open vessels. This system consists of an air supply, pressure regulator, constant flow meter, pressure transmitter, and a tube that extends down into the vessel.

Bubble air through the tube at a constant flow rate. The pressure required to maintain flow equals the liquid’s specific gravity multiplied by the vertical height of the liquid above the tube opening. Figure 2-21 shows a bubbler liquid level measurement example.

Figure 2-21. Bubbler Liquid Level

Measurement Example.

AIR

T

X

Let X equal the vertical distance between the minimum and maximum measurable levels (100 in.).

Let SG equal the specific gravity of the fluid (1.1).

Let h equal the maximum head pressure to be measured in inches of water. Let Range equal zero to h.

Then h = (X)(SG)

=100 x 1.1

=110 inH2O

Range = 0 to 110 inH2O

20

mA dc

4

0 110

inH2O

2-33