Pressure sensor for acid tank level measurement


Thread Starter


I need a pressure sensor to measure the level of acid in a tank. The sensor must be of lfush diaphragm type preferably. I have already installed a sensor whose diaphragm was corroded.

There are a number of ways to measure your tank level. However to tell you which is the best with out further process and mechanical data would take a while.

I would recommend a radar level transmitter with a Hastelloy C horn if you have top access and overfill protection against getting process acid on horn.

If not a simple flange mount isolating diaphragm level transmitter made of tantalum will work. Be sure to get correct flange size, flushing port, and range. Rosemount or equal is a good source for the flange mounted differential pressure transmitters. One other point on the tank is it atmospheric, padded, or under vacuum. This will determine whether you will require absolute or
gauge pressure transmitter. I would also recommend transmitter being a smart one with hart protocol. On your tank connection I would also recommend putting an isolating valve between tank and transmitter. Isolating valve could be simple teflon lined plug or ball valve with same flange size and rating as tank flange.

Remember all exposed parts of the process should be of same materials of construction for acid.
The manufacturer should be able to help you specify exactly all options you will need.

If no Flange and tank has spare nozzle on top you coul do a simple bubbler system.

Hope this helps.

Koblenz, Mykel MH

Our acid tanks use a bubble pipe (Shock horror), and have been running for a while now without any dramas, thus removing the need for a special diaphram.

Are any of the other level measuring technologies possible or are you contrained to what you already have.


you don't say what type of acid we are looking at here. However not a great issue. All of the major instrument manufacturers eg ABB, Emmerson (Rosemount), Foxboro, Endress & Hauser, etc. have appropriate chemical resistance charts. All have standard flanged diaphragm transmitters.

Probably the best option is if you don't specifically need a pressure measurement is non-contact. Ultrasonics with either Peek or Teflon head is a very good low cost method. If you have a problem you don't need to empty the tank to fix it. Radar is OK but unless its a pressurized vessel is over priced for your results.

George Fischer offer a pressure sensor for the aplication that you need, the model is 3-2450-UH,this sensor is special for to use in acid, the body of the sensor is PVDF. you can to find more information in their website

check the specifications. sorry my english.

matthew hyatt

Check with Honeywell, they make a wide range of pressure transmitters and possibly have a off-the-shelf product for your application.

Others are:

All have very good websites and technical support.

Matthew Hyatt
Technical Consultants
[email protected]

Michael Eggebrecht


I had the same problem, solved it by using Transmitter with Hast Alloy C on the Flange Mounted Transmitter facing. Most of the Better Transmitter Company's now Carry this Product for your Application.

Good Luck

Jamal Osmani

For corrosive application, such as your application we recommend non contact level measurement shuch as radar type, we had already installed some KROHNE level radar model BM 702 with wave stick antenna (PTFE material) in some acid application and they are in operation for a long period without any significat problem.

If you can tell us more detail about your process (fluid, pressure, temperature, tank connection and ....) we can advise you right level meter.

Be careful with hydrostatic sensors such as PT with diaphram seal there is no possibility for on line maintenance and transmitter replacement.
There are several radar companies that can satisfy the measurement. Ohmart/Vega, Magnetrol, Thermo, Siemens and Saab can all do the job.