IR tank level measurement

[vortexmc]

hey there, i am doing a design project the involves distance sensing and measurement in in tank with water mixed with a colour dye. I have established that measurement using time of flight would be quiet difficult as it is stated that i must use a PIC microcontroller for the detection. I have decided on using the intensity of light approach. The Tx and Rx circuit i have chosen is attached. My question is, using an IR receiver module in the diagram, how would i gain an analogue output so as to use an ADC?Any suggestions would be useful.

If u guys have better suggestions as to a different approach, i would love any kind of input in this regard.
Thank you.

 

[MikeMl]

Your posted circuit is using an IR remote-control chip usually found in a TV or Stereo. The TSOP series of IR receivers are used to decode digital modulation that is modulated onto the IR beam. It has no output which is "proportional" to the received IR beam intensity, which it seems to me, is what you would need to measure how much the IR beam is attenuated by the dye in the column of fluid.

I think your basic approach is flawed. The degree of attenuation of an IR beam due to the length of the path in the fluid is likely to be a very strong function of the dye concentration, much more so than the length of the path.

 

[Dr_Doggy]

IR transistors are bad for range since they are digital, i would recommend using photo sensors and a voltage detector circuit,

you can use the IR transistors but then you will need to measure pulse delay time to get your distance and at the speed of light, that may be hard, even at long range,

 

[Externet]

Agree. Infrared does not look promising for that.
I always suggest the same on these projects : Replace the pointer with a potentiometer and you can have a accurate analogue reading for your ADC PIC port.

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