I have a project where I have a panel that is currently installed in a non hazardous area but that needs to be pressurized.

I need to measure the internal pressure of the panel to ensure that it does not exceed 2.5 kPa.

The transmitter will be installed in a panel that does not have any access to the outside so a DP transmitter is not an option. The panel needs to be kept above 50 Pa.

Are there any suggested brands or any other way that I can get the ranges and resolution I need.

All help appreciated.

Thank you.

 

You can't have your cake and eat it, too.

> the internal pressure of the panel to ensure that it does not exceed 2.5 kPa.

> The panel needs to be kept above 50 Pa.

Which pressure are you talking about?

I suspect that this is for explosion proofing the panel by purging. Is that the case?

 

An absolute pressure transmitter will do that, a DP cell with one side evacuated. Some in-expensive ones can be found in the catalogs like Omega or Cole Palmer

Why can't you connect to the outside? you would get better resolution that way using a normal DP cell with a lower range.

 

Why you want the transmitter to be installed inside the panel? You can install the transmitter outside the panel and tube the high pressure port to the panel. In this way you can you can use the inbuilt indicator of the transmitter as a local indication of the pressure. It will also be useful to adjust the air pressure of the panel using a manual valve at the inlet line.
If you want to install the transmitter inside the panel, that will also do. In this case you can connect an impulse tube at the low pressure port and connect it to the panel wall outside to sense atmospheric pressure. An absolute pressure transmitter also will do. Everything is possible.

You need an measurement range of 2.5 KPa i.e. 0.025 bar i.e.250 mm wc. This is not a very low pressure at all in the industry. Differential or gauge pressure both are available at this range. Absolute pressure transmitter is also available. Pl. check the Rosemount 3051 model for example.

 

I think a process pressure transmitter like a 3051 is way overkill

Something like a blind plastic strain gauge for <$100 mounted inside the panel wit LP connection to the outside is more what I had in mind.
We would need to know some more details like what it is connected to (I/O available), approval required, etc.