Amprobe ULD-300 Ultrasonic Leak Detector

I used this to locate a pesky gas line leak. It's fantastic! It wasn't absolutely necessary (I used bubble solution before I bought this, but there was one connection outside just before the meter that I never bothered to check, and the ULD-300 honed in on it right away.)The full story is that a pro did my gas line install, then I added on at a few places. At some point I lost the ability to hold 30 PSI and couldn't find the leak with my homemade dish soap and spray bottle solution, so I aired the system up to 120 PSI and eventually bought a bottle of the blue Oatey Mega Bubble stuff. Of course, pressurizing to 120 PSI meant any questionable joints blew out, and the bubbles found a half dozen locations that needed my attention. I finally threw in the towel and picked up the Amprobe at an open box discount.The instrument is about the size of a bottle of fuel system additive. It comes in a soft-shell zippered carrying case with a parabolic dish attachment, a "focused" attachment, and a sloppily cut length of rubber tubing to use like a stethoscope. There's also a junky pair of '80s style Walkman headphones, and mine had the 9V battery already installed (but maybe because it was open box? Not sure...)The "learning curve" is minimal. There is a high and low volume setting, a 1x, 10x, and 100x sensitivity selector, and a thumb wheel that acts like a squelch control on a 2-way radio, and really just fine tunes the sensitivity vs. the background noise. There's a constant hiss of static played through the headphones, but the static changes as you swing the probe towards the leak, or other ultrasonic emitters such as CFL light bulbs. There is also a 10-step LED bar that provides a visual indication of sound being detected.Unsure what to expect or listen for, I first picked up the whine of some fluorescent bulbs, then of a leaking fitting on my air compressor hose. After that, a walk along the mostly exposed gas line listening for any change in sound. This proved very effective from a few feet away (great, since most of my run is up in the ceiling). At one point I honed in on a fitting that it turned out was reflecting noise emitted from that leaky air compressor hose, which was about 6 feet away from me. I also got a false read from some pink fiberglass insulation I gently pushed up against to expose a fitting -- although I couldn't see the insulation moving, it popped off with an ultrasonic-range "crinkling" that definitely didn't sound like an air leak, but stood out prominently against the background noise.Eventually, after finding nothing inside the house, I ended up outside at the start of my system. Zeroed in on the pipe cap that's a place holder for where the gas company meter will eventually be installed. Hadn't even bothered to check this because the plumber did it, and it was holding pressure for him prior to me tearing into his work. As it turns out, I think this is where he had his test gauge installed, so this cap was added on only after his test was completed and while it held 30 PSI, I must have blown it out with 120 PSI.Now the question is what to do with this tester. But I think I can make a little side money renting it out locally on Craigslist since I was searching for rentable Ultrasonic testers prior to making this purchase. Ultimately, the bubble solution would have found this leak had I looked there, but this tester is certainly the preferable method for me.Only question to answer is whether it would easily find a live gas leak at 1/2 PSI?!? I'll test that and and update this review in the coming days.

Been using this for several years now. One side of the headphone frame broke but I used some tape to fix it. Otherwise.. it does a good job of pinpointing refrigerant leaks.

I believe this would work well for different applications, but A/C needs to have a rather large leak or the surface wet down. This was not convenient for me, so I found it not able to be applicable to my work. I sent it back.

I find leaks nobody else can find and find them fast. It take a small learning curve to get the sensitivity dialed in for each job. It gets you close to the leak then if you don't see it or can feel it use bubbles. Its the ONLY leak detector to have. I have owned most all of the high quality (sniffers) and most say theres a leak when exposed to a temperature change until they get cold. The ultra sonic is not affected by anything except backscatter noise and wind. It even picks up fluorescent ballast humming. DONE DROP IT EVEN A FEW FEET!That is how my previous 4 quit working. They are very fragile. I keep mine in the front seat.Even as costly as they are they pay you back on the first difficult leak WARNING: the other brand cheap ultrasonic is no comparison and useless for refrigeration leaks. Save your $40 and buy the AMPROBE.I service supermarkets and its a must for leak detection in big store with long runs. Insulation can hide a leak though but a small slit in the insulation and feeling for oil will tell you where to remove insulation to find leak.

Ambient noise hurts but used several other sonic leak detectors and the amprobe has been the best for our use

I vacuum bag composite parts and I purchased this to help find leaks. First, it is affected by my light fixtures so I have to search for leaks in the dark. Second, this only finds the largest and most obvious leaks. I can find smaller leaks with my good old ears. Maybe it works better for applications but it was a waste of money for vacuum bagging.

Dirt cheap for an ultrasonic air leak detector but I needed it to find compressed air leaks in a very noisy manufacturing environment. It picked up a lot of other noise like shop fans, etc. and I got a lot of reflection off of hard surfaces so it was hard to pinpoint even a very large leak. For the price, it can't be beat. I bought a MUCH more expensive unit to meet my needs.

If you work with Carbon Fiber in a vacuum baggin situation this is the only leak detector you should buy. Yes, there is ambient background noise you can not get rid of. However.... there is no other detector that will detect vacuum leaks like this thing can. Even with the background noise, the leak will be amplified beyond the ambient sound. Once you dial in the high, low, and volume settings based off what youre trying to hear, there is nothing better for carbon or glass work.