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TDC1000 & Non-Invasive Flow Monitoring Questions

ihearth2o
Intellectual 780 points
Other Parts Discussed in Thread: TDC1000, LM2733

Hello,

I read through the users guides for TDC1000-TDC7200EVM and TDC1000-GASEVM, as well as app notes SNIA020 and SNAA266A. I had a few high level questions still and was hoping for some of your expert input:

 - Since the TDC1000-TDC7200EVM is developed for flow meters that have access to the water flow (invasive setup), would an external boost such as in GASEVM be required for clamp on (noninvasive) water flow monitoring around a (e.g.) 2" copper pipe? If so, do you have a recommended part?

 - Can GASEVM be easily modified for non-invasive water flow monitoring? In other words, what is TI's recommended easiest path to prototype non-invasive water flow monitoring?

 - The circuitry required to enable non-invasive water flow monitoring seems relatively "cheap". Am I missing something about the technology or application of it? I am curious as to why current ultrasonic flow meters on the market costs thousands of dollars. I just want to make sure I'm not missing something obvious here that is required for this type of meter I am describing to function....

Thank you!

  • 0
    TI__Mastermind 21685 points
    Hi,

    All our flow meter experience are with invasive setup. Also, we mostly used off the shelf flow meter sensors to interface to TDC1000. A list of ultrasonic flow meter manufacturers is listed in Appendix A1 of the SNIA020 app note. Relevant standards for water flow meter and accuracy requirements is briefly discussed in Appendix A2. Without a properly engineered flow meter sensor (with highly symmetrical transmit and receive signal path), it's very difficult to meet the accuracy requirements of these standards. That's the reason we don't have recommendations on non-invasive water flow monitoring.


    Thanks,
    Vishy
  • 0 in reply to Vishy Viswanathan
    Intellectual 780 points
    Hi Vishy,

    Thank you for the response. A couple follow up questions:

    - Is the highly symmetrical transmit/receive path what drives the cost up on these meters?
    - Do you have a recommended platform on top of which we can build a prototype non-invasive flow meter?

    Or are you unaware of these answers because TI has not pursued this non-invasive setup?
  • 0 in reply to ihearth2o
    TI__Mastermind 21685 points
    Hi,
    - We really have no idea on what drives the cost.
    - We have not tested GASEVM+BSTEVM for waterflow monitoring.
    a) Note the boost converter (LM2733) of the BSTEVM has a switching freq (1.6MHz) that might cause interference to 1MHz water transducer.
    b) You can look at the SNAA284 app note Section 2.2 to understand the receive signal path and the external components required. You have to customize receive path for 1MHz transducer.
    c) Check this post as well
    e2e.ti.com/.../444026

    Thanks,
    Vishy