sound sensor w/analog output 1

[spuds]

Does anyone know of a sensor that detects sound and has an analog output. It will be in a noisy environment but would need to be able to detect the sound of an air leak. To the human ear it's easily heard but there's not always someone there to hear it. The analog output would be input to the plc and set an alarm.
thanks in advance

 

[ICman]

I've got a handheld sound level meter from Pulsar. They might have something. Their Website is:

http://www.pulsarinstruments.com.

They are located in England.

. . . Steve

 

[plcsavvy]

I would use a pressure switch that is adjustable. you simply set the pressure level at which the switch closes.
When the switch closes it sends a signal to the input of the plc. this inturn generates an alarm and stops the machine etc. Why would you want to hassle with analog signal processing if you can make your life a lot easier by using a discrete digital signal? Also, I don't think you are aware of the complexity involved in the device that you decribe. What you are describing is a pseudo voice recognition device that will sample the analog input of the sound generated by the air leak, digitize it and store it in some non volatile type of memory such as eeprom for later comparison. Furthermore the device must be capable of canceling any back ground noise in order to correctly distinguish the sound of the air leak from an infinite possibility of sounds of varying amplitude and frequency. This is virtually impossible.

best regards, plcsavvy

 

[Macbeth]

Although you can hear the air rushing out, there are many litle eddy curents in the leak that you can not hear. Much like a dog wisle.

Look at these there are many others.

http://www.ultrasonicdirectory.com/suppliers/sagetechnologies.html

 

[skills]

I know nothing about your application; but, if you are interested in detecting a leak why not build a leak detection system instead of fiddling around with acoustic signals, which as was suggested above, is extremely complex and subject to a whole host of failures. A microphone is such a device; but, you can't learn much other than the presense of noise with it, whereas, a leak detection system can quantify very very small leaks in systems.

 

[spuds]

I have an ultrasonic sensor that I can test it with, I'm not sure what freq and sound level range it works with but I can try it. The machine uses some air because it has multiple solenoids, I'm sure the air pressure fluctuates enough that a discrete pressure switch would'nt see the leak accurately.

thanks again guys