[SBE] Ultrasonic Leak Detection

[Chris Spacone]

Maybe the guys on the list can help: 

 

I would like to avoid pouring lots of soapy water all over waveguide
flanges, couplings and the rest of the system to find a nagging leak or
leaks. Recently we had some construction done that impacted our uplink room.
It became necessary to remove the house air from the waveguide
pressurization manifold that fed three sections running to separate dishes.
To replace the air source we purchased a 200 bottle of dry nitrogen and the
related regulators, bits and pieces. Of course, after hooking it up we
discovered that there was a leak in the manifold that had probably been
there forever. After finding the manifold leaks using the 'soapy water'
method I came away from the exercise with very clean, lemony fresh smelling
hands and a really nasty case of potty mouth.

 

I still have leaks but it appears that they are after the pressure gauges
feeding the waveguide sections. Three of the sections come out of the
switching plumbing located in the top of the rack (of course it is above the
HPA's, where else!) and feed elliptical sections with flanges and pressure
windows. I recognize that I can shotgun the problem but I'd rather have a
more deterministic way of resolving the problem. I looked into something
called ultrasonic leak detection. As I understand it, the process uses a
microphone that picks up the ultrasonic noises created by the turbulence of
a leaking gas. This noise is amplified, heterodyned and presented to an
operator where they get some kind of aural and / or visual indication of the
location and magnitude of the leak.

 

Here is the question(s): Anybody have any experience with ultrasonic leak
detectors? If so are they a vast improvement over shotgunning the problem?
Any recommendations for a source / manufacturer? Perils / pitfalls?

 

And one last: In LA is there any local shop or goodguy that can provide
waveguide bits and pieces? I don't necessarily mind dealing with the 'big
vendors' but I really don't need the sales visits and the rest of the hoopla
that comes with that deal.

 

Regards,

Chris Spacone, KD6OUB