A strange phenomenon with pressure transmitters
Thread Content
Yesterday I encountered a strange phenomenon~ The pressure transmitter read 4.00 KPa before the cover was placed on it; once the cover was put on, the reading increased to around 4.10. When the cover was removed again, the reading dropped back to its original level. But as soon as the cover was put back on, the reading rose again~~~ I’m not sure what’s causing this issue~~
4 KPA is a very low pressure value; perhaps the movement of the transmitter’s position while you are closing the lid is causing the change in pressure!
The question is indeed very strange; looking forward to the answer
With the lid on, the heavier end goes down – balance is what matters most; a little floating isn’t a big deal. If it’s not installed properly, it can float quite a lot.
Maybe it’s magnetic induction. Take another look.
Since it is used for experiments, the requirements are quite high; for now, it can only be used without a cover
I don’t know what the range of your transmitter is, nor what type of transmitter it is ? ?
I have encountered this phenomenon. Really. The cause was not found. Finally, it is finalized by closing the lid. Could you tell me which manufacturer it is?
We have encountered similar situations before; for example, when calibrating EJA differential pressure transmitters, as well as those made by Weiran and Rosemount, it is required that they be level. Of course, they must also be level during installation as well. If they are not level, there will definitely be systematic errors. But in your case, it’s hard to say – what brand is the transmitter, what is the operating environment like, and are there any strong interference sources in the vicinity? It would be best to send a picture.
Does the position change when you cover it and when you don’t? For example, whether the positive and negative pressure chambers are kept at the same level.
So what exactly is the standard? Should I put the lid on or not? It seems that covering it with a lid is still the proper approach
Please check whether there is any short circuit in the cover and the signal cable
There are two possibilities: 1. The wiring terminals of the transmitter may have become grounded when the cover was closed; 2. There is external interference, and closing the cover can reduce this interference
A high-precision pointer pressure gauge should be installed on the pipeline connected to the transmitter, to be used for comparison and error determination.
After the lid was put on, the position of the diaphragm box tilted, I guess that’s what happened.
In fact, some situations are indeed somewhat incredible, with many things happening by chance. 1. First, consider the aspect of quality. It is recommended to conduct tests on the static pressure and zero drift of the transmitter, as well as to check whether the diameter of the pipeline in which the transmitter is installed and the way it is secured are appropriate. This situation can also occur if the pressure guide tube is too thin and too long, and is suspended without any fixation. 3. Are there any interference sources in the on-site installation and usage environment?
I also think electromagnetic interference is a significant factor.
It depends on the type of pressure transmitter; if it is a dry-type instrument such as one with ceramic thick-film or ceramic capacitors, it might be due to pressure buildup inside the transmitter’s chamber； In the case of capacitive transmitters, it may be due to factors such as the installation location ； Another issue is electromagnetic interference.
I haven’t encountered such a problem yet
Do all transmitters have such problems? I always thought it was only electrical converters that did this.