HC-SR04 Arduino: Can I Measure Frequency Changes to Identify Materials?

Hi there!
I'm Kazem. I have recently purchased a HC-SR04 (an Ultrasonic range finder), I used Arduino Uno and was able to find ranges in inch and Cm. It works base on transmitting ultrasound and receiving echo. By calculating the delay finding the range, therefore it works by time delay. My question is that: Is there any way to use this board (HC-SR04) and by manipulating program see the changes of frequency instead of time?
I want to use it to recognize different materials base on different frequency, is it possible?

Hi kazem

The short and easy answer is no there isn’t reason being is that a 10us pulse is issued to the module which cause the module to emit a 40khz sound burst The ultrasonic sensors themselves are only designed to resonate at btw 38khz to 42khz They are transducers mini speakers if you like or piezo elements

Ideally want is something along the lines of an electromagnetic signal to detect different materials this is entirely different to bouncing sound waves of fixed objects using reflection Using electromagnetic waves induced in a coil is what your after

You have a transmitter coil and a receiver coil you are looking for changes in magnetic flux picked up by the receiver coil

This is classified as VLF" Very Low Frequency (below 30kHz). The coil oscillates at 30 khz producing an electromagnetic wave

A transducer such as what you have produces NO ELECTROMAGNETIC WAVES

It produces sound waves, very different ,

The most popular metal detection technology at the present time, includes the "LF" Low Frequency (30 to 300kHz) instruments made for prospecting.


Your measuring with your module reflected waves in the air reflected back by some object Not Magnetic waves which is what your after

Hope that explains this for you

This is ideally what you want for use with atmel, arduino based micos

http://www.miymd.com/index.php/projects/tpimd/

Thank you Mark.
I will do some search on magnetic induction detection, but my main purpose of detecting different material is to recognize different types of pipes for first step. Next to try to detect leakage in them.
I have seen many Ultrasonic leak detector so I'm trying to make a cheap and simple one.
Maybe it's better I ask how can I detect leak by ultrasonic sensors (for example 40khz, MA40S4R as I have them in hand) in a pipe!?
Is it possible by producing 40 khz and send it to a transducer, receive different frequency for a pipe with different condition ? (different condition I mean in healthy pipe, pipe with leakage, broken pipe)

I think you are getting confused with this A gas sensor looks similar to an ultrasonoc sensor by means of the grid which is over the sensor but its not ultrasonic

Want you want here is a gas sensor They use ultrasonic detectors for detecting water level leaks but this is done using a fluid level principle or inside a tank for example where the sensor still emits sound but is reflected by the water level inside the tank These are narrow beam ultrasonic transducers

See below
http://www.controlcomponents.com.au/products/...ms_liquid_level/gl20_gl21_Ultrasonic_Bchr.pdf

A gas sensor detects leaks also entirely different to an ultrasonic sensor

See below
http://www.electroschematics.com/6669/sen-1327-lpg-gas-sensor-module/

Hopefully that should answer your question

Hey Guys well i think that Ultrasound sensors work on a concept similar to sonar which assess features of a focus on by decoding the reflects from stereo or sound surf respectively.Thanks!!

Thank u mark.
I would appreciate if send me a link for building a simple leak detector home usage!
regard!