vacuum bag leak detector

I am looking for an affordable unit that will not cost an arm and a leg, yet effective Any thoughts?

 

I have the AccuTrack, about $375 I think I paid. It works pretty good. It's weakness is around fluorescent lights, causes a lot of interference and it doesn't cancel other noises very well like some of the higher priced models. However it definitely can find leaks you would have a hard time finding without one.

 

I have the same one,works well on the bigger leaks but wont find the tiny ones.

 

The cheapest we have used is a 1/4" or 3/8" thick wall tubing about a yard and a half long. One side to the ear, the other side to the vacuum bag. It works. Works best if you stick the open end to your ear and the other end parallel and touching the bag.

Stethoscope works also but we remove the flat circular end as it blocks the leak.