Tag: sound level

The Trick To Adding Sound Levels Of Multiple Sources

Published on by Russ BowmanLeave a comment

If I put a 10 pound weight on a scale, the scale will read 10 pounds. If I put another 10 pound weight next to it, the scale with now read 20 pounds.

If I have $10 bill in my pocket…well, that’s a LOT more cash than I usually carry. But if I somehow come into possession of another $10 bill and put it in my pocket, now I have $20. And it probably won’t be for long.

If there’s an EXAIR Model 1100 Super Air Nozzle supplied with compressed air at 80psig, and my Sound Level Meter is reading a level of 74 dBA, and I hook another one up right next to it, my Sound Level Meter now reads about 78 dBA.

Wait, what? Did we just break math there? You, and your ears, will be happy to know that there’s perfectly valid math behind the third (as well as the first two) statements above. The third one’s just a little different, that’s all.

See, sound power (that’s “how loud” sound is, as measured at the point of generation) and sound pressure (“how loud” it is, as measured at the point where it’s heard) are both quantified in units called decibels. And, unlike mass or wealth (the first two examples above), which are linear & additive, measurement of sound power & pressure is done on a logarithmic scale. That means simple arithmetic won’t work…we have to use a logarithmic equation to ‘add’ those sound levels together. It looks like this:

Combined Sound Level (dBA) = 10 x log10[10SL1/10 + 10SL2/10 + 10SL3/10 …]

Where “SL1”, “SL2”, “SL3”, etc., are the sound levels, in decibels, for the “noisemakers” in question. So, for the two Model 1100 Super Air Nozzles, generating 74 dBA each:

10 x log10[1074/10 + 1074/10] = 77.65 dBA

And just to prove the math works, we made a video of a real live test:

All EXAIR Intelligent Compressed Air Products are engineered & manufactured to be safe, efficient, and as quiet as possible. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Sound Levels in Your Facility

Published on by Jordan T ShouseLeave a comment

One of the most common and dangerous hazards that occur within a manufacturing and production facility is the noise level within the plant. Noise is measured in units known as decibels. Decibels are a ratio of the power level of the sound compared to a logarithmic scale. If an employee is an exposed for too long to high levels of noise, they can begin to lose their hearing. That is where the OSHA 29 CFR 1910.95 regulation comes into play.

Hearing loss is the best known, but not the only, ill effect of harmful noise exposure. It can also cause physical and psychological stress, impair concentration, and contribute to workplace accidents or injuries.

This OSHA standard doesn’t just provide the protection against noise in the work place but monitoring as well. Companies shall provide at no cost audiometric tests for all employees to ensure that no damage is being to the hearing of all personnel. This program is to be repeated every six months and the results are to be made accessible to all personnel.                

Hearing is very important to our everyday lives and must be protected due to the fact that once it is damaged hearing loss cannot be lost be repaired. The OHSA 29 CFR 1910.95 is there to protect and monitor this dangerous hazard in the workplace so that all employees can go home safe and sound.

Here at EXAIR we design all of our products to safe and quite. Weather it is using one of our mufflers for vortex tubes or E-vac’s or one of our Super air nozzles we strive to meet and exceed the OSHA standard. One could also purchase EXAIR’s Digital Sound Level Meter which can give a accurate and responsive reading of how loud your compressed air sources are.

For more information on EXAIR’s Digital Sound Level Meter and any of EXAIR‘s Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer

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What is Sound: The Correlation Between Sound Power and Sound Pressure

Published on by codybiehleLeave a comment

Sound, it is all around at every given point of the day. Whether it is from the music we listen to, the person talking to you, your cars engine, or the wind blowing through the leaves there is no escaping it. Hearing is one of the five senses that the majority of humans rely on and should be protected at all costs and with a good understanding of what sound is, one can help mitigate damage done to their hearing. Sound can be broken down into two parts, sound power and sound pressure. But the real question is, how do these corollate to each other to become the sound that we rely on.

Sound Wave

Sound Power (Watts) is defined as the rate at which sound energy (decibels) is emitted, reflected, transmitted or received, per unit of time. Whereas, Sound Pressure is defined as the local pressure deviation from the ambient atmospheric pressure, caused by a sound wave. Based on these two definitions it can be determined that sound power is the cause that generates the sound wave and sound pressure is the effect or what we hear after the sound wave has traveled to the ear.

This can be summed up in a simple analogy using a light bulb. Light bulbs use electricity to generate a source of light, this means that the power required (also stated in Watts) to cause the bulb to light up is comparable to Sound Power. The intensity of the light being generated (stated in Lumens) would be the Sound Pressure. Sound Pressure is what we would typically hear or call sound. This is what is measured because that is the harmful aspect to our hearing and ears. If the Sound Pressure is high enough and the ear is exposed to it long enough, permanent damage can be done resulting in hearing loss to the point of complete hearing lose.

I have known many people who have lost there hearing either completely or a large portion of it from exposure to loud noises. EXAIR designs and manufactures quiet and efficient point of use compressed air products. These products either meet or exceed the OSHA noise Standards in OSHA Standard 29 CFR – 1910.95 (a).

The OSHA Standard for how long someone can be exposed to a certain noise level

If you are not sure what the noise level is in your facility check out EXAIR’s Digital Sound Level Meter. It’s an easy to use instrument for measuring Sound Pressure levels in an area.

EXAIR’s Digital Sound Level Meter

If you have questions about the Digital Sound Level Meter, or would like to talk about any of the quiet EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR or any Application Engineer.

Cody Biehle
Application Engineer
EXAIR Corporation
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What is a Decibel Level?

Published on by Jordan T ShouseLeave a comment

Decibel level also known as dBA, is how the industry measures sound intensity’s effect on the human ear and is an important value when discussing noise exposure for employees and operators within manufacturing. Manufacturing personnel can be at risk for hearing damage when exposed to high decibel levels if the proper precautions are not taken. For reference, 0 dBA is the softest level that a person can hear. Normal speaking voices are around 65 dBA. A rock concert can be about 120 dBA.

Sounds that are 85 dBA or above can permanently damage your ears. The more sound pressure a sound has, the less time it takes to cause damage. This damage occurs within a sensitive part of our ear called the cochlea, which contain thousands of hair cells used to allow our brains to detect sounds. For example, a sound at 85 dBA may take as long at 8 hours to cause permanent damage, while a sound at 100 dBA can start damaging hair cells after only 30 minutes of listening.

OSHA Max Noise Exposure Chart

The Center for Disease Control (CDC) estimates that 22 million workers are exposed to potentially damaging noise at work each year. Whether you work near machinery, at a sports venue, on a tarmac, or operate a jackhammer—hearing loss is preventable.

Noise may be a problem in your workplace if you:

  • Hear ringing or humming in your ears when you leave work.
  • Have to shout to be heard by a coworker an arm’s length away.
  • Experience temporary hearing loss when leaving work.

If you need to raise your voice to speak to someone 3 feet away, noise levels might be over 85 decibels. Sound-measuring instruments are available to measure the noise levels in a workspace.

The first step to lowering your sound level is to take a baseline reading of your various processes and devices that are causing the noise. EXAIR’s Sound Level Meter, Model 9104, is an easy to use instrument that provides a digital readout of the sound level. They come with an NIST traceable calibration certificate and will allow you to determine what processes and areas are causing the most trouble.

From there, EXAIR has a wide range of Intelligent Compressed Air Products® that are designed to reduce compressed air consumption as well as sound levels. For noisy blowoffs where you’re currently using an open-ended pipe or a loud commercial air nozzle, EXAIR’s Super Air Nozzles are the ideal solution. Not only can they pay for themselves over a short period of time time due to compressed air savings, but your operators will thank you when they’re able to hear later on in life!

 EXAIR has the tools you need to reduce sound level in your processes. If you’d like to talk to an Application Engineer about any applications that you feel could benefit from a sound reduction, give us a call.

Jordan Shouse
Application Engineer

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