At Carl's Pro Band we are always progressing and constantly searching for new and innovative ways to improve our results. One of the best additions to our shop in the last few years has been the Magnehelic gauge. We use the "Leak Tester" model from MusicMedic.com and it has really elevated our finished product. Here is a brief description of it's use from MusicMedic.com:
The Magnehelic gauge on the face of the Leak Tester gives a reading that quantifies the amount of air leaking from an instrument. The higher the number, the greater the leakage. Simple but extremely effective.
We use the Leak Tester for woodwind work and also at the brass bench. We have used this tool in the past to test for leaking solder spots, red rot, etc... in brass instruments, but recently have added valve and overall instrument leak testing to our Ultrasonic Cleaning process. Now you can feel secure knowing your instrument has been thoroughly tested for even the most minute air leakage.