I have a buried tank that we need the level measurement on, and we have a differential pressure transmitter available. Can we use it? We can only access the top of the tank.
Expert’s answer: Bubbler system for differential pressure transmitter
You had to make it difficult, didn’t you? No, no, it’s all right. I got this. It involves a bubbler system… But let’s take it from the start.
Yes, you can get the level measurement of your tank from the top with a pressure transmitter. Other devices would make it way easier. But I get it. You gotta use what you have, and you have a pressure transmitter.
On the bright side, bubbles! Yes, bubbles! My bubbles! Ahem. Combine your transmitter with a bubbler system and you can totally measure your hydrostatic level. But! You need an air or gas supply to make your bubbles. Take a look at the pic to see what I mean.
Here’s how it works. A low level in your tank creates a low hydrostatic column. With me so far? No? Okay, I’ll bring it down some more. Low column means less pressure. The bubbles encounter less resistance than when you have a high level. Thus your transmitter translates that into your level pressure. When you have a high level, your bubbles have to work harder to go up, and the transmitter says, “Aha! That means more pressure!” Hope that makes sense, because I don’t know how else to describe it. In conclusions, bubbles.
For the more advanced kids in the audience, have some calculations:
P100% = high pressure side – low pressure side
P100% = [(liquid column height x product density) + (tank height at 100% x product density)] – (tank height at 0% x product density)
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