Lost In The Din? Not With An Ultrasonic Leak Detector!

Have you ever found yourself in a noisy environment, trying to hear what someone is saying to you? They could speak up, but sometimes that’s not enough. You might find yourself cupping your hand to your ear…this does two things:

*It blocks a lot of the noise from the environment.  This could also be called “filtering” – more on that in a minute.
*It focuses the sound of the speaker’s voice towards your ear.

IMG_1339
“What? They’re ALL still RIGHT behind me?”

Now, this isn’t a perfect solution, but you’ll likely have much better luck with this in a busy restaurant than, say, at a rock concert. Especially if it’s The Who…those guys are LOUD (vintage loud). If you’re at one of their concerts, whatever your friend has to say can probably wait.

You know what else can be loud?  Industrial workplaces.  Heavy machinery, compressed air leaks, cranes, forklifts, power tools, cranky supervisors/personnel…there are lots of unpleasant but necessary (mostly) sources of sound and noise, right here, where we work.

In the middle of all this, your supervisor might just task you with finding – and eliminating – compressed air leaks…like the person I talked to on the phone this morning.  This is where our Ultrasonic Leak Detector comes in: in places with high noise levels, it could be difficult (if not downright impossible) to hear air leaks.

Most of that noise from the machinery, cranes, etc., is in the “audible” range, which simply means that it’s of a frequency that our ears can pick up.  In a quiet room, you could likely hear an air leak…all but the very smallest ones will make a certain amount of noise…but when a compressed fluid makes its way out of a tortuous path to atmospheric pressure, gets turbulent, and creates an ultrasonic sound it is a frequency that our ears CAN’T pick up on.

Not only does the Ultrasonic Leak Detector pick up on this ultrasonic sound, it can also block (or “filter”) the audible sound out.  It comes with a parabola and a tubular extension so you can hone right in on the area, and then the exact location, of the leak.

If you’d like to find out more about compressed air leak detection, how much you might be able to save by fixing leaks, or how this could make your supervisor a bit less cranky (no guarantees on that last one,) give us a call.

Russ Bowman
Application Engineer
Find us on the Web
Follow me on Twitter
Like us on Facebook

 

IMG_1339 courtesy of Rich Hanley  Creative Commons License

A Sound Reckoning Of The Super Air Knife

In May of 1976, The Who performed a concert in London that Guiness’ Book of World Records used to certify them as the World’s Loudest Band. A sound level of 126 decibels was recorded and documented at a distance of 32 feet from the stage. That’s right at the boundary of the threshold of pain.  Which I’m sure is what they were going for.

There are a variety of charts available that relate common noises to the decibel levels they could be expected to produce. For instance, a DC-9’s engines produce a sound level of about 120 decibels at takeoff or landing. Now, imagine if such a plane were to land at the aforementioned concert: would the sound level, at a given distance, be equal to those two decibel levels added together?

The answer, of course, is no, because we’re talking about sound pressure level. It’s not EXACTLY the same as fluid pressure, but a decent analogy is that, if you have an air compressor supplying your system with 100psig compressed air, turning on your other, identical air compressor won’t result in 200psig in your system.

I mention this for a couple of reasons. One; I’m a BIG fan of The Who, and I heard one of my favorite songs of theirs on the radio this morning: “You Better You Bet,” from their Face Dances album, which came out in 1981 and hence would not have been played at the 1976 Loudest Band concert, but I digress.

The other reason is because of a conversation I had with a caller about the sound levels produced by our Super Air Knives. The published sound pressure level is 69 dBA. “dB” is short for decibels; “A” means the unit is weighted to express the relative loudness of sounds as perceived by the human ear. Anyway, the caller was interested in knowing how much louder our longer Super Air Knives were than their shorter counterparts. The answer is, of course, they’re not louder…for the same reason that your second air compressor doesn’t double the air pressure in your system, which is the same reason that the fictional jet landing at the rock concert wouldn’t double the sound level.

Now, a couple of things to consider: the sound pressure levels that we publish were measured at a distance of 3 feet to the side of the Super Air Knife. Sound levels at a closer distance, and/or in front of or behind the Air Knife, will be different. Also, the Super Air Knife was blowing into free air. If the air flow is impinging on a surface, there will be a sound level associated with that as well. If it’s in excess of the 69 dBA that the Super Air Knife is producing, then that’s what your ears are going to be subject to.

All things considered, though, the Super Air Knife is INCREDIBLY quiet, considering the amount of air flow it’s producing. The science behind this has to do with what makes them so efficient with their use of compressed air: their entrainment ability. The Super Air Knife’s design allows it to use the primary compressed air flow to entrain enormous amount of air from the surrounding environment. This entrained air not only multiplies the resultant flow rate produced, but forms an attenuating boundary layer, which effectively reduces the sound level produced by the high velocity compressed air.

The Super Air Knife entrains air at a rate of 40:1, relative to its compressed air consumption.
The Super Air Knife entrains air at a rate of 40:1, relative to its compressed air consumption.

If you’d like to find out more about how EXAIR Intelligent Compressed Air Products such as the Super Air Knife can reduce your air consumption AND your sound levels, give me a call.

Russ Bowman
Application Engineer
Find us on the Web
Follow me on Twitter 
Like us on Facebook