Hi,

The August 1999 edition of Everyday Practical Electronics has a feature on
an ultrasonic puncture finder.

They have a site at: http://www.epemag.wimborne.co.uk/

It may do what's required. I wonder if a suck sounds the same as a blow?

Rgds...

...Andy
At 18:53 29/06/99 +1000, you wrote:
>Roger, in Bangkok wrote:
>
>> I expect their problem is with connectors and seals, and they have
>> asked for help to locate and correct the problem.  Seems simple enough
>> to sniff around with a tiny microphone.
>
>  I seem to recall that one approach to tiny air leaks is to consider
>that the wavelengths of sound emitted are likely to be comparable to the
>size of the defects.  This suggests that you might look for *ultrasonic*
>frequencies for starters.
>
>  Two advantages of looking for ultrasonics are that there is less
>ambient noise and most ultrasonic detectors are *very* directional.
>--
>  Cheers,
>        Paul B.
>