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BOOST-TUSS4470: Time of Flight for Lubricant in 2 inch to 4 inch CPVC pipe

Part Number: BOOST-TUSS4470

Hello,

I am looking at using an ultrasonic time of flight measurement to characterize a process of making lubricants with various viscosities and additives.

Preferably I would be able to make this measurement from the outside of the PCV pipe that the lubricant is flowing through.  The pipe is CPVC and varies from about 4 inches to 2 inches in different parts of the mixing station.

Right now the products from TI that I am looking at are the TUSS4470 / BOOST-TUSS4470 / MSP430F5529LP.  I would like to know what is the suggested setup for measuring in a non-invasive way.  Should I use one transmitter / detector and have the signal bounce or a straight through pipe measurement.  Does the ultrasonic signal have an issue going around or riding the pipe instead of through the pipe – through the lubricant I am measuring – through the other side of the pipe?

Am I looking at the correct hardware to accomplish this?

Thanks,

John

  • Hi John,

    Depending on whether you are attempting to make a flow measurement or a concentration/identification measurement, there are a few options available.

    If you need to know the flow rate, then the MSP430FR6047 is the best option.

    If you need to measure the viscosity, keep in mind this should be done in a static setting (no flow). In this case, you can use the TUSS4470, TUSS4440, PGA460, or TDC1000 depending on the frequency of the transducer you use (each device supports a different maximum frequency).

    Its difficult to measure the characteristics (concentration/viscosity) of the flowing medium if you do not know the flow rate in advance, as both the flow rate and viscosity will affect the accuracy of the time of flight measurement.

    Typically, special pipes are used for non-invasive measurements in a flow system, such as the Audiowell DN-25. See the Water Flow Meter Quick 
    Start Guide for an example ( http://www.ti.com/lit/ug/slau810/slau810.pdf ).

    If no-flow measurements is an option, then yes, you can also connect the transducer to the outside of the pipe for non-invasive measurements. You have the option using a single transducer (mono-static) to make a round-trip measurement, or separate emitter and receiver transducer pair (bi-static) for a one-way pitch and catch measurement. Things are less likely to go wrong in a bi-static setup, so I recommend this approach.

    Since you are emitting through the exterior of the PVC pipe, you may need a high voltage transducer. We do not have much experience capturing ultrasonic measurements through PVC material, so you will need to perform a feasibility analysis for yourself. You can find some transducer examples here: PGA460 Transducer & Transformer Listing. If you select a transducer operating at 200kHz, then all the aforementioned devices can be used depending on the type of data you need from the IC.