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I have mounted a piezo-ceramic ultrasonic transducer (MODEL # SMD10T2R111WL, Vendor Website: PIEZO CERAMIC DISC 10X2MM R 215 KHZ WIRE LEADS) under a plastic tank using epoxy. Please see the below picture.

[1]: https://i.stack.imgur.com/sN7Sj.jpg

I am trying to confirm that the wire did not get detached from the transducer while mounting. Is there a way to test it. The two wires that are soldered to the transducer are not connected so there is no way to check the continuity of the wires using multi meter short circuit test.

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  • $\begingroup$ Do you have a digital multimeter? $\endgroup$ – Eric S Mar 13 '17 at 20:03
  • $\begingroup$ Yes, I do. Can you please explain your suggestion? Thanks. $\endgroup$ – Niloy Talukder Mar 14 '17 at 18:26
  • $\begingroup$ Well, can't you just check that the resistance is sufficiently low? Most DMMs have a continuity setting where it beeps if there is a connection. $\endgroup$ – Eric S Mar 14 '17 at 18:59
  • $\begingroup$ Hi Eric, I just explained why I cannot do a continuity test with multimeter. Thanks. $\endgroup$ – Niloy Talukder May 8 '17 at 21:08
  • $\begingroup$ I still don't understand why you can't do the continuity check. The wires go somewhere. Just put one probe on that end and the other on the solder pad on the transducer. $\endgroup$ – Eric S May 9 '17 at 23:25
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I suggest you use circuit similar to the below. The test circuit shown as below may be used to measure the resonant, anti-resonant, and impedance characteristics of ultrasonic transducers.

Piezo Ceramic Transducer Test Circuit

  • Adjust frequency to obtain maximum EOUT. Switch in VR and adjust to obtain the same output. VR now equals the minimum series impedance.
  • Adjust frequency to obtain minimum EOUT. Switch in VR and adjust to obtain same output. VR now equals the maximum series impedance at the antiresonant frequency.
  • Measure phase between voltage EU and EOUT to determine impedance characteristics.

I suggest reviewing Application Notes on Ultrasonic Ceramic Transducers for additional details. Additionally take a look at Selection and use of Ultrasonic Ceramic Transducers. This almost identical to the first but has some additional details.

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If you can't do a continuity test then test the capacitance - 450pF at 1kHz as per the specs you refer to.

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Apply a small voltage to the piezo from a signal generator, maybe around 1 kHz. If you can hear something, then the wires are connected. A few Volts should be good enough, and won't damage the piezo, especially one that size.

Conversely, you can connect the wires to a scope and see if there are any voltage spikes as you jar the device the piezo is attached to. Be careful that this doesn't cause the piezo to touch anything other what it is already mounted on. Otherwise, the voltage spikes could be due to the leads picking up static charges from different objects. You want to make sure you are getting voltage spikes only from mechanical stress on the piezo.

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  • $\begingroup$ These are good suggestions. $\endgroup$ – Eric S May 9 '17 at 23:26

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