TDC1000-C2000EVM: TDC1000-C2000EVM ' problem

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Part Number: TDC1000-C2000EVM
Other Parts Discussed in Thread: TDC1000

TDC1000-C2000EVM is used for various problems in flow measurement:
The setup of the experimental device:
The resonant frequency of the piezoelectric ultrasonic transducer dedicated to water flow measurement is about 350Khz, and the temperature sensor is not used, and the user GUI settings are shown in the figure：

The problems with zero flow measurement are:
1) There is a large deviation in the 0 flow measurement, the measurement result should be around 0ns, but the test result is about tens of microseconds, and the error is particularly large.
2) After testing with an oscilloscope, I found that the START signal, STOP signal, and COMPIN signal are not the expected shape, which caused great interference to my measurement.
I very much hope to provide accurate register settings, hardware configuration and oscilloscope display settings for flow measurement using TDC1000-C2000EVM and 350Khz ultrasonic transducers.
Attach the display of START signal, STOP signal and COMPIN signal on the oscilloscope

over 2 years ago

0 Isaac Lara over 2 years ago

TI__Mastermind 19630 points

Hello Lei,

As I mentioned in one of our previous threads the TDC1000-C2000 is not the recommended device for flow metering. This is due to its low accuracy, the TDC1000 is known to miss the first STOP signal causing incorrect TOF measurements. As well as its ability to only determine binary flow, at medium to high flow rates. Which means that it cannot determine zero flow appropriately.

The device that is currently recommended for flow metering is the MSP4306047. Here is this thread that links useful documentation for flow metering using the MSP device mentioned: https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/950622/tdc1000-water-flow-measurement?tisearch=e2e-sitesearch&keymatch=TDC1000%2520missing%2520stop%2520pulse%2520water%2520flow#

Here is another thread that contains good info on the TDC1000 flow metering: https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/946044/tdc1000-water-flow-metering/3502131?tisearch=e2e-sitesearch&keymatch=TDC1000%25252520zero%25252520flow#3502131

Lastly, the TDC1000 Liquid Coupled FAQ contains excellent links to help you mitigate this issue if you are still interested in continuing with the TDC1000, as well as touches on other questions you may have about the device.

Best,

Isaac

0 JOIN over 2 years ago in reply to Isaac Lara

Prodigy 90 points

Hello Isaac,

Problems with TDC1000-C2000EVM flow measurement:
The ΔTOF measured during zero flow measurement is always around 30 microseconds instead of around 0s.
The oscilloscope can display the START, STOP, and COMPIN signals, but the TOF between the START and STOP signals is not the time required for the ultrasonic wave to propagate between the two sensors, but is much longer than the ultrasonic wave propagating between the two sensors. The time required. And when I change the distance between the two sensors, the START signal and STOP signal on the oscilloscope still maintain the original time difference. I want to know the cause and solution of this signal error and ΔTOF error in general.

0 JOIN over 2 years ago in reply to JOIN

Prodigy 90 points

To add to my question: the compin waveform displayed on the oscilloscope will not change with the distance of the sensor, and the distance between it and the START waveform will not change due to the change of the distance between the sensors. This should be a mistake Waveform, want to know the cause and solution of this problem

0 Isaac Lara over 2 years ago in reply to JOIN

TI__Mastermind 19630 points

Hello Lei,

When you change the distance between the two sensors and you can see the signals on the oscilloscope have you measured the time in the oscilloscope to verify if the measurement the GUI is providing correlates with the signals in the oscilloscope?

I want to see if I can replicate this issue on my setup, are you still using the same settings as above or are you using different settings for this test?

Best,

Isaac

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TDC1000-C2000EVM: TDC1000-C2000EVM ' problem