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

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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EXAIR Product Overview: Mufflers

Noise, we all hate it to some extent. From the hustle and bustle of crowed streets to the whine of a jet engine noise has plagued the world for eons leaving people to search for a way to escape into a moment of peace and quiet. The majority of people that I know pack their massive over sized backpacks and head deep into the mountains for days on end to escape the noise sometimes traveling for 10+ miles at a time. But how can we help eliminate this monstrosity that we have created in our manufacturing environments? The answer is mufflers, and no I don’t mean your car muffler (although they do the same thing) I mean compressed air mufflers. Compressed air can be a loud utility inside of a plant environment and exceed the OSHA guidelines for personnel noise exposure. But this noise can easily be mitigated with the use of Intelligent compressed air products and mufflers.

Big Sandy Lake Trail – Wind River Range State Park, WY

OSHA Standard 29 CFR 1910.95(a) outlines the total noise exposure to a particular noise level per day and dictates that noise exposure at or above 85 decibels require ear protection. By placing a muffler on the end of the pipe one can reduce the sound level significantly to the point it could be the difference between having to wear ear protection and not having to. With that being said EXAIR offers four different types of mufflers to choose from and they are Reclassifying, Sintered Bronze, Straight-Through, and Heavy Duty.

Reclassifying mufflers offer the best noise reduction at 35 dB and have the added benefit of removing oil mist from the air line. This means that the Reclassifying mufflers are ideal for pneumatic cylinders. Per OSHA Standard 29 CFR 1910.1000 worker shall not be exposed to more than 5mg/m3 of oil by volume in a 40-hour work week. The patented design of the removable element separates oil from the exhausted air and meets or exceeds the OSHA Standard.

Sintered Bronze Mufflers are an excellent low-cost solution which can be easily installed into your current existing ports. These mufflers also come in the largest variety of different sizes ranging from thread sizes of #10-32 to 1.5” NPT. Also, the Sintered Bronze Mufflers are specifically designed to provide the minimal amount of back pressure and restriction. The main difference between these mufflers and the reclassifying is that the Sintered Bronze Mufflers cannot collect oil out of the exhaust.

The quick pick chart for easily choosing which muffler you need

If the process air needs to be directly plumbed away from personnel, then the Straight-Through Muffler is the way to go. Straight-Through Mufflers are ideal for situations that require both a threaded inlet and exhaust. In most applications you will see the Straight-Through Muffler pair with our E-Vac vacuum generators or Vortex Tubes to provide noise reduction of the unit. All in all, the Straight-Through Muffler can reduce noise levels up to 20 dB.

Model 3913 Straight-Through Muffler

Lastly, the Heavy Duty Muffler provides a corrosion resistant aluminum outer shell with a stainless steel inner screen. This design allows the muffler to catch any contaminants such as rust from being ejected potentially causing harm or quality defects. Typically, this muffle will reduce noise levels up to 14 dB.

Model 3903 Heavy Duty Muffler

If you have any questions or want more information on EXAIR’s E-Vacs and their Accessories. Give us a call, we have a team of application engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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The Soft Grip Safety Air Gun for OSHA Compliance

Compressed air has many different uses ranging from simple cooling and blow off applications all the way to operating machine cylinders and robotics. One of the most common uses is for simple cleaning; whether its cleaning off a work station or blowing off personnel it can’t be denied that air powered cleaning is very useful. But if the Occupational Safety & Health Administration (OSHA) regulations are not followed it can also be unsafe.

Open-ended blow offs can inadvertently be dead ended (the airflow outlet can be completely blocked), when this happens if the pressure is to high an air embolism can form in an individuals bloodstream. Blowing something off with air can result in airborne particulate traveling at a high velocity that can become embedded into your skin or in your eye.

With all that being said this is where the safety air guns step into the spotlight! It’s pretty easy to make a safety air gun that complies with the dead-end pressure regulation; just give the air another path to take when the outlet is blocked. The most common solution found is a cross drilled nozzle which allows the air to escape when the end is blocked. Generally the problem with this design is that the nozzles can be very loud and inefficient. In most cases these nozzles have paid attention to the dead end problem but ignored the noise level exposure safety issue and completely ignored compressed air efficiency. 

With EXAIR’s Super Air Nozzles you get both the added benefit of being safe, quiet and efficient. Our engineered designed air nozzles are commonly installed onto a Soft Grip Safety Air Gun to make an ergonomic, safe, and quiet Safety Air Gun. These can also have a  Chip Shield added to help prevent particles from flying back and hitting the user. The Soft Grip Safety Air Gun can also be coupled with a pipe extension from 6” to 72”; you can also add one of our Stay Set Hoses 6” in length to 36”.

Soft Grip Safety Air Gun with Stay Set Hose. eg. 1210-6SSH

Here are a few examples of the Soft Grip Safety Air Guns in our product line:

Cody Biehle
Application Engineer
EXAIR Corporation
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Can Fish Hear & Other Noise Exposure Facts?

When I was visiting a supplier in Japan, our host was extremely proud of their koi pond and wanted to demonstrate something. He took us to the pond’s edge and clapped his hands. From the murky depths of the pond emerged huge koi breaking the surface with open mouths. As their reward, he tossed them a handful of fish food.

While everyone else was enamored with his ability to have trained the fish, I was awestruck with the fact that they could hear the sound of clapping deep down into the pond. No wonder dad kept telling me to be quiet or you will scare the fish away.

According to the National Wildlife Federation fish don’t have ears that we can see, but they do have ear parts inside their heads. They pick up sounds in the water through the lateral lines that runs down each side of its body and transmitted to their internal ear.

While human auditory abilities may not be as sensitive as the rest of the animal kingdom, the inner workings of our ears are very sensitive easily damaged. Listening to loud noise for long periods of time can damage the hair cells in the inner ear. Noise-induced hearing loss usually develops gradually and painlessly. We live in a noisy world and hearing loss among Americans is significant. According to the Center for Hearing and Communications, approximately 12% of the U.S. population or 38 million Americans have a significant hearing loss.

For 30 years EXAIR has been designing and manufacturing compressed Super Air Nozzles, jets, knives, and amplifiers that significantly reduce sound levels and compressed air costs. Protect your hearing as well as your employee’s and save money by contacting our application engineers and they will show you how.

Joe Panfalone
Application Engineer
Phone (513) 671-3322
Fax   (513) 671-3363
Web: www.exair.com
Twitter: EXAIR_JP

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