Ultrasound acoustic sensor

Hello everyone,

I'm working on a project and I need to record the ambient sounds in its ultrasound spectrum.
I need something like the HC-SR04, but in place of converting the ultrasound data to distance I need that data about the ambient sound in its raw format.

Thank you, Regards.

You don’t want an ultrasonic ranger - they are mechanically highly resonant at the rated frequency, and virtually useless for spectrum analysis.
Besides, rangers only return presence or absence of signal, there is no information about the spectrum of the signal.

GrooveFlotilla:
You don’t want an ultrasonic ranger - they are mechanically highly resonant at the rated frequency, and virtually useless for spectrum analysis.

I need an ultrasound microphone like stuff to analyse the sounds generated by a working industrial machine to detect anomalies and defections.
any idea ?

One of the scientific supply houses?
Sennheiser?
Bat detectors?

But you're going to need a processor with a little more horsepower than an eight bit microcontroller.

maybe interesting tutorial for Piezo sensors

https://learn.sparkfun.com/tutorials/piezo-vibration-sensor-hookup-guide

Note the frequency of the sensors is allways limited by the sample frequency of the ADC of Arduino.

Wide range microphones exist e.g. Petterson M500 but they are expensive and no Arduino has anywhere near enough processing power to record the output from them.

Perhaps you can specify exactly what frequency range you need to analyse. Just “ultrasound” covers everything over about 20KHz, potentially a very wide range indeed. And if you’re looking for problems with machinery you need to cover the audio range too.

Steve

robtillaart:
Note the frequency of the sensors is allways limited by the sample frequency of the ADC of Arduino.

That's just over 9k sps so ultrasound is out when using that ADC (highest frequency is 4.5 kHz). You need a much faster one.

I have a bat scanner, kind of bat detector on steroids, scanning the whole spectrum from 15-120 kHz. It uses electret condenser microphones, and they're tiny. The ADC you need to digitise a signal like this would have to record at least 240 ksps.

Now I don't know what frequency you want to go to, but let's stick to that 120 kHz.

Limit yourself to 8-bit single channel sampling and you have a 240 kB/s data stream. Not sure if an Arduino can handle that - the best you can expect it do with that much data is channel it to an SD card for storage. It won't be able to do any analyses, like what frequencies it's recording.

Should I consider switching to Microprocessor shields like the raspberry ?

Maybe.
Your project description is far too ambiguous to give a strong suggestion there.

The microphones in the old Polaroid Sonar cameras are extremely broad band, and the cameras can be found dirt cheap at thrift shops.

However, you need a 200V bias supply to use them.

To acquire and record ultrasound data, you will need a fast microprocessor with lots of memory and a good ADC, capable of at least 200,000 samples per second.