I want to use the Ping))) sensor to measure the speed of sound through water

Hey guys, as my title suggests, Is it possible to use the ping sensor to measure the speed of sound through water? I want the sound to be able to cross an interface and bounce back towards the microphone to record results.

Do you have any suggestions on how I can go about this? If the PING can't do it, can you suggest something which can?

some thoughts:
sound is a pressure wave which depends on temperature and salinity. especially temperature is easy to measure to.

given that the speed is about 1500 mtr per second means it travels about 1500 centimeter in 1000 microseconds

So you should take a tube of e.g. 2 meter, give it a hard tick on one end (servo) and measure the pressure wave coming by at 1 meter and at 2 meter.

ideally you need a sensor that can trigger an arduino interrupt to get optimal timing. but I don't know what one that fits, sorry

I want the sound to be able to cross an interface and bounce back towards the microphone to record results.

If by "interface" you mean the air/water interface, keep in mind that most of the pressure wave will be reflected back from the interface and very little will continue on into the water.

In fact, there will be a reflection from just about any interface between two different materials. Look up "acoustic wave reflection coefficient".

some old thread which might be interesting - Arduino Underwater Sonar/Altimeter - Product Design - Arduino Forum -

(googled arduino sonar)

Is it possible to use the ping sensor to measure the speed of sound through water?

No.

I want the sound to be able to cross an interface and bounce back towards the microphone to record results.

How would that measure the speed of sound in water?
You would need to know the distance from the sensor to the water and the depth of the water, assuming it is bouncing back off the bottom.
However there will be so little sound even entering the water and less still bouncing off the bottom and even less crossing the water / air boundary that it will be impossible to detect any secondary return echo from the water.

Also 40KHz is not a good frequency for propagation through water, most systems use something higher in the KHz region.