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Plastic Chemical Tank Monitoring Application

Jason Parmenter
Intellectual 410 points


Hello TI Team,

We would like to monitor the liquid level of 4' x 4' x 4' plastic chemical tanks.   Any ideas of how we could use the TDC 10000 series chip to perform this task.  Maybe a transducer stuck to the bottom of the tanks like the demo video?  I assume it would not work from the top of the tank (through air) from earlier discussions on range limitations? 

Thanks!

  • 0
    TI__Expert 4725 points

    Jason,

    That would work. For a 4 foot tall tank you have to make a few changes:

    1. You'll either need a "acoustic waveguide" or "level tube" inside the tank. If you read my level appnote (www.ti.com/lit/an/snaa270/snaa270.pdf) I briefly discuss them there. This will depend on your fluid and if its has solids etc. in it. This does 2 things.

    a. It allows you to receive echos even if if there is a disturbance on the fluid surface. (ie during filling from the top, tank in motion etc.)

    b. Allow you to detect a longer distance measurement with the same transducer. (ie: using a 1cm diameter transducer and a level tube I was able to measure level up to a meter at up to a 45deg angle. 

    2. Using our TDC1000-GASEVM, you'll a higher excitation voltage on the transducer. It has a 30V boost circuit on it that level shifts the TX pulse up to 30V. In the app-note I reference above I show the relative performance of a transducer with and without higher voltage excitation. However for 1Mhz operation you'll need to do the following:

    1. To modify the TDC1000-GASEVM for 1-2Mhz operation: swap C27/C32 from 510pf to 51pf
    2. Use Ext_OSC input to drive an external 8Mhz clock source into board via J8 and moving jumper on JP6 to pins 1-2.

    Make sure you read my other app-note about mounting procedures. (www.ti.com/.../snaa266)

    Best Regards,