Leak detector

If you have the money get a hellium leak detector

Wow! 1000-2000€ for used leak detector. I wonder why it so expensive. Is it from titanium? Got mine from Ebay for around 60€.

Since I’m a electronics guy too, I looked about the voodoo behind it. There are basically two different ultrasonic detector technologies. The first one is basically a frequency divider, better versions have a volume restoration, because frequency division is done digitally and destroys the level. With this units you can hear a wide spectrum, but it sounds a little weird.
The second one is called a heterodyne detector and this one mixes the ultrasound with another ultrasonic sine wave. If you have the correct frequencies the mix will generate a audible beat frequency. You can tune this to a specific frequency, but the bandwidth is rather narrow.

Both devices can be built at home with 30-40$ parts. If interested google for “bat detector”.
Can anybody tell me what makes the professional device so much more expensive?
Is there a special feature I’ve overseen?

I am not an electronics guy. I always was under the impression that electronics run on smoke: Once the smoke is out of the tool, it does not function anymore…

What is available on these units is an on/off button, a sensitivity slider, and basicly that is it. Volume is regulated by the headphone. (and for 500-1000 usd you get a rather cheesy one)

Has anyone given the bar detector idea a try?

Hi Herman I saw you can supply the airtech sontector 33 and I’m interested…can you contact me at palesmartino@yahoo.it

used helium leak detector are not badly priced.

I have been using the accutrak leak detector for years and they are great. $350

http://superiorsignal.com/products/ultrasonic-instruments/accutrak-vpe-ultrasonic-leak-detector

For any of the electronically minded here, these leak detectors are exceptionally simple circuits. I built mine for a total cost of AUD$17.00. Works like a charm after I worked out the kinks.

EDIT - I will read the thread before I post…
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I will read the thread before I post…
I will read the thread before I post…
I will read the thread before I post…
I will read the thread before I post…
I will read the thread before I post…

The Inificon Whisper I got works well

Hanaldo, which type of circuit did you build? And do you use any special microphone or sound focussing device?

This is my circuit:

No nothing special, I just used a 40kHz transducer. Works very well, and I played with the idea of using a parabolic reflector to increase sensitivity but it really isn’t necessary.

Can you share schematic?

thanks