Pressure sensor

[Giuseppe MPO]

Hi all,
I think I have read, on this forum, someone who has used a Honeywell ABP2 series pressure sensor, to measure the height of a liquid.
I've done several searches but I can't find it anymore.
It could also be that I'm wrong and it's not this forum....
In this case, I apologize for the question.

[TimB]

I have used a whole host of pressure sensors to measure liquid hight.

A few things to consider

1 Work out the pressure you would expect to see at the max water level. Say mmh2o to millibar then from that you can choose right pressure range.

2 Check they can handle liquid or moist air. Some sensors have a coating to keep them safe.

As for reading them I see the Honeywell ABP2 can talk i2c or SPI. Looking at an image of them I might have used one in the past so cannot be that hard to code for

My consensus in the end was while they can resolve to very small changes in WL eg ~1mm they drift a lot so unless the scale needed is bigger e.g. in 5mm increments I did not trust them.

[Giuseppe MPO]

I have to measure a height of liquid (water) of maximum 2 meters, which should be around 200mbar, I think I'm using a 500/600mbar full scale sensor. I'm not interested in great precision 5mm are just fine.

[Peter Truman]

Hi - I have to agree with Tim - I've used several different pressure sensors to determine the level of water in a variety of tanks. Pretty much over the same size (2 to 3 meters) that you are looking for. Over the years I've ended up replacing all of them with either magneto resistive sensors, simple float switches or ultrasonic sensors mounted above the surface.

Using a pressure sensor has always seems to be a good idea - until it isn't. I think it would be fine if you were looking for maybe 5 meters depth or more and with a resolution of say 100mm+, but drift (even with really expensive SICK sensors) lets you down when you want really fine control. In my case I most often just need maybe 5 points (full, 1/4, 1/2, 3/4 empty) so its not really worth the hassle.

Either that or the farmer runs over the mounting with a tractor (they break everything)

 

[RGV250]

Hi,
On the large vats when I was at work we used load cells and did it by weight, it was up to 40,000 lts though. We never used pressure sensors as I would expect them to drift with atmostpheric pressure.

Bob