Bubbler Panel

Bubbler System Process

The bubbler system works by forcing a gas (compressed air) 

at a near-constant flow rate out the bottom of an open 

tube (bubble/dip tube) submerged in liquid. The back pressure 

in this tube is measured. With the process liquid’s density known, 

the level can be calculated using the back pressure and 

density. A pressure transmitter converts the back pressure to 

provide a 4-20ma output to a controller, which calculates 

the liquid’s level.

As the liquid level increases, the head pressure on the bubble tube gets higher. This means more pressure is needed to maintain a constant flow rate to overcome the pressure of the fluid.

If the fluid level goes down, so does the head pressure on the bubble tube and the pressure required to maintain constant flow rate of air or gas.  

To minimize maintenance requirements, we can add a purge line to clear the bubble tube of debris and buildup. This can be a manual operation with the push of a button, or automated with a purge schedule and timer.

https://www.instrumentationtoolbox.com/2014/06/bubbler-tube-system-for-level.html?m=0

https://automationforum.co/troubleshooting-advantages-disadvantages-and-application-of-the-bubbler-type-level-measurement-system/