reflective component

[bubulindo]

I'm looking for a coating or a plastic tape that changes it's reflective properties if there is water behind her or not.

The purpose is to detect the level of water in a glass container via a reflective infrared sensor.

Can someone help me???


Best regards, Carlos Cardoso

 

[kenvlach]

There are a number of plastics (PFA, PP, PVDF) that you could use as a film on the inside of the glass. The IR beam will bounce back from the PFA/air interface, but be refracted away (into the liquid) by a PFA/water wetted surface. See the electro-optical liquid sensor at

http://www.omega.com/Green/pdf/LV170.pdf

It shows optic & electric schematics.

These sensors are rather pricey, and generally only used to detect fluid at a fixed point, e.g., as leak detectors. I used a similar product to satisfy a continuous monitoring requirement for leak detection beneath a liner in a metal finishing containment berm. In order to use for liquid level sensing, you would need some means of vertical scanning (moving the beam and detector up and down). There are less expensive means of liquid level measurement.

Another vendor site is

http://www.netmotion.com/htm_files/fh_leak.htm

Hope this helps,
Ken

 

[negotiator]

A simple vertical plastic 1/4" rod at point of I.R. beam.
Difference of ambient-to-water point will be obviously magnified. I.R. receiver will show density signal. Taa-Daa.
(Where's my dollar ?)
Non-invasive, 5-minute fix, Radio Shack 'n back !!!!!!!!

 

[negotiator]

A simple vertical plastic 1/4" rod at point of I.R. beam.
Difference of ambient-to-water point will be obviously magnified. I.R. receiver will show density signal. Taa-Daa.
(Where's my dollar ?)
Non-invasive, 5-minute fix, Radio Shack 'n back !!!!!!!!


thestocksguy@hotmail.com