TDC1000_TDC7200 weird result

Xiao Tian Wang

Other Parts Discussed in Thread: TDC1000

I got a problem, I mount the sensor at the bottom of the container, and whatever the liquid level changes, the evm give me the same result, around 38000ns. Even before I mount the transducer(leave it in the air), the result is still 38000. I have connected with scope, scope shows me the same result.

Thanks

William

over 9 years ago

0 Matthew Minasi over 9 years ago

TI__Expert 4725 points

I'd suggest you read my app note on Liquid Level Sensing from the bottom to get you started. www.ti.com/.../snaa270
regards,

0 Xiao Tian Wang over 9 years ago in reply to Matthew Minasi

Prodigy 50 points

www.youtube.com/watch

I have seen your video and I did the test according to your configuration. I can see your result increase from 27000(empty) as you filling water in. But my one, whatever I increase or decrease the water level, the result always remains 27000. I doubt it is a mounting problem or the water cell material problem, what do you think?

0 Matthew Minasi over 9 years ago in reply to Xiao Tian Wang

TI__Expert 4725 points

I suggested you read the app note I referred to as it will walk you through the process of understanding how your transducer is working in your system, which is key to knowing how to configure the TDC1000.

My guess is your "weird result" is due to "false echo detection" during the ringdown of your transducer. I go over all this step by step in the app note I previously mentioned. Specially in sections 3.3.3-3.3.7.
I'm glad you found the video but it is intended as an overview.

Best regards,

Sensors

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TDC1000_TDC7200 weird result