A fairly new device on the repair persons workbench is a device called a Magnehelic, or MAG machine for short. Normally used to test after a setup it is also handy to quickly identify a leak somewhere, say, on a clarinet or flute.
A MAG machine is a very sensitive leak detection tool that determines the amount of leakage in an instrument (measuring the difference in air pressure versus the pressure lost due to leaks) . This is actually an opposite type of test from the simple "At home Clarinet leak test" and of course much more accurate.
viewtopic.php?f=232&t=166
The MAG machine actually blows air and helps to find leaks that cannot be found with the more common leak light (good for flute) or feelers (good for clarinet).
To use the device one must first close up all holes in a clarinet. This can be done with rubber stoppers, and cork wedges to get the two other ring keys. Then another stopper with a tube going to the mag machine is inserted into one of the ends of the clarinet joint.
When you turn on the machine a 0 will show a perfect 100% seal, and an 8 will show a wide open hole somewhere (on the large round gauge).
Here's a quick clip on using a MAG machine. The leak is on the throat Bb, The machine shows 4 (a leak somewhere) and I simply push down on the Bb and you can see the dial drift downwards.
http://www.clarinetperfection.com/work/example/mag.mpg
The tool is also useful if one happens to over look a tonehole or tenon crack, or finding unsealed register or thumb hole vents.
The tool can also be used to test the porosity of pads themselves. So there is a difference in the quality of pads, easily testable by this device.
Hope this helps in understanding one of the methods a technician may use to test your instruments setup.
A MAG machine is a very sensitive leak detection tool that determines the amount of leakage in an instrument (measuring the difference in air pressure versus the pressure lost due to leaks) . This is actually an opposite type of test from the simple "At home Clarinet leak test" and of course much more accurate.
viewtopic.php?f=232&t=166
The MAG machine actually blows air and helps to find leaks that cannot be found with the more common leak light (good for flute) or feelers (good for clarinet).
To use the device one must first close up all holes in a clarinet. This can be done with rubber stoppers, and cork wedges to get the two other ring keys. Then another stopper with a tube going to the mag machine is inserted into one of the ends of the clarinet joint.
When you turn on the machine a 0 will show a perfect 100% seal, and an 8 will show a wide open hole somewhere (on the large round gauge).
Here's a quick clip on using a MAG machine. The leak is on the throat Bb, The machine shows 4 (a leak somewhere) and I simply push down on the Bb and you can see the dial drift downwards.
http://www.clarinetperfection.com/work/example/mag.mpg
The tool is also useful if one happens to over look a tonehole or tenon crack, or finding unsealed register or thumb hole vents.
The tool can also be used to test the porosity of pads themselves. So there is a difference in the quality of pads, easily testable by this device.
Hope this helps in understanding one of the methods a technician may use to test your instruments setup.