• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 31 subscribers
  • Views 1182 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TDC1000-TDC7200EVM: Level of sludge in a tank

Lucas Barzotto
Intellectual 310 points

Part Number: TDC1000-TDC7200EVM

Hello everyone,

I've been working with the TDC1000-TDC7200EVM in level measurement of water in a tank, using the transducer SMD15T21R111WL (1MHz) and I've had great results. But now I want to measure the level of a sludge in a tank of water using the same ultrasonic method, as in the following image:


I checked the application reports provided by Texas, such as http://www.ti.com/lit/an/snaa265/snaa265.pdf but I couldn't think of a solution to this.
Would it be necessary to use two transducers? One fixed in the bottom of the tank and the other one floating? How would be the config of the registers of the GUI?

Thanks in advance,

Lucas

  • 0
    TI__Mastermind 23810 points
    We are out of office for the Thanksgiving holiday, but our TDC1000 expert will respond to you next week.
  • 0
    Intellectual 310 points

    Hello again,

    I was planning to use the sensor in the same way it's used in this video:

    https://www.youtube.com/watch?v=jgFQZmJZxyI

    In other words, with the sensor submerged.

    To test it, I put some sand and water in a recipient (the same that I made some water level tests), and fixed the sensor on it, as in the following images:

    At first, I tried the same GUI config I was using for water level measurement, but no data were send to the graph. Then I increased the PGA gain to 12dB, and the graph started to show some data (about 30000ns) but even if I moved the sensor higher or lower (or increased the sand level), the same TOF was read.

    I'd like to know if you guys have any idea for my project to work. May the problem is the GUI config? or the way the sensor is fixed? should I use a pipe or something?

    The sensor is 1MHz and the GUI config for water level I was using is the following one:
    /cfs-file/__key/communityserver-discussions-components-files/1023/ConfigLEVEL.txt

  • 0 in reply to Lucas Barzotto
    TI__Genius 11015 points
    Lucas,

    The transducer will reflect the sound from the various medium that it passes through. If you have lumps of sand say in the container you will have multiple reflections from it and that will report error readings. it is advisable to use ultrasonic solutions if there is no sludge dissolved in water.
    We can use ultrasonic to measure contamination in liquids provide the solution is homogeneous.
    Also if the slurry is clearly at the bottom of say water (as shown by your original picture) it should work.

    Alternatively,I would mount the transducer from top, this way you will get 2 reflections 1 from water at top & 2 from the slurry at the bottom.
  • 0 in reply to Bharat Aravamudhan
    Intellectual 310 points

    Thanks for your reply Bharat,

    I tried to measure the level of clean water mouting the transducer from the top, as in the following images:


    With the same GUI registers. I was expecting to read the TOF of the sound reflected by the surface air/water, but no data was displayed in the graph, the TOF was zero all the time.

    Any ideia to solve this?

  • 0 in reply to Lucas Barzotto
    TI__Genius 11015 points
    Hello,

    In the config shown per your diagram, looks that the plastic is pretty thick for the transducer to send echo through it to the air and then to the water. Try to mount the transducer to the to the internal surface to the plastic (exposing it to the air directly above the water, that should work.