No-contact liquid height measurement

[S-T-G]

I need to measure the height of a liquid in a tank. A sensor that does not contact the liquid is prefferable. The sensor has to measure (approx.) 1/2 inch to 1 foot with at least 1/8 inch resolution. Any suggestions?

[Ben · Accepted solution]

Keyence?

Ben

[Intaris]

That would have been my answer too.....

Shane.

[Coq_Rouge]

If this is a school project perhaps some sort of electronic weight, or load cell may be used. Given that your container is uniform of course. But I admit this solution may be somewhat awkward in other settings

[Intaris]

Depending on the size / shape / connections on your tank it might be possible to weigh it.

I know of many processes where the contents of a tank are monitored by simply having the tank sitting on a weighing scale.... That's also not contacting the liquid and is probably a lot cheaper than a keyence sensor.

Shane.

[MattBradley]

In terms of technology (besides weight, which is always good and easy), two other methods come to mind:

1) Acoustic

2) Fiber-optic

Are there any other constraints in your measurements?

[unclebump]

Take a look at hydepark ultrasonic sensors or ifm efector. Keyence also has an ultrasonic as well.

http://www.sesensors.com/content/en/products/ultrasonic-sensors.asp

http://www.ifmefector.com/ifmus/web/padv02_30_10_10.htm

http://www.keyence.com/products/sensors/ultrasonic/fw/fw.php

Does the liquid have any foam in top?? Foam can cause some trouble with the ultrasonic sensors. Submersible pressure transmitters can also have problems if they get clogged up on the screen.

[S-T-G]

Another constraint (& partly the reason for non-contact), the liquid in the tank will be heated to 105 degrees C.

[unclebump]

That's a really big constraint. The heat coming off of that will probably melt an ultrasonic sensor. Sounds like weighing the tank might be the best option. Use a load cell underneath the tank. How large is the tank??

[unclebump]

Try Endress & Hauser. Look at level and radar systems. Probably not very cheap though. Temps up to 700 degrees F.

http://www.us.endress.com/