What is a Decibel Level?

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

Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS

Video Blog: Laminar and Turbulent Flows

I have written blogs about laminar and turbulent flows as related to the Reynold’s number.  Now, let’s demonstrate the difference between the two flows and the advantages of laminar flow from EXAIR’s engineered air nozzles; as demonstrated by our VariBlast Safety Air Gun.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Keep Your Pneumatics “Healthy” and “Running Like a Brand New Car”

Compressed air systems are used in facilities to operate pneumatic systems, and these systems are vital for industries.  So, it is important to keep them running.  The system can be segregated into three different sections; the supply side, the demand side, and the distribution system.  I like to represent these sections as parts of a car.  The supply side will be the engine; the distribution system will be the transmission; and, the demand side will be the tires.  I will go through each section to help give tips on how to improve the “health” of your pneumatic system.

From the supply side, it will include the air compressor, after-cooler, dryer, and receiver tank that produce and treat the compressed air.  They are generally found in a compressor room somewhere in the corner of the plant.  The air compressor, like the engine of your car, produces the pneumatic power for your plant, and needs to have maintenance to keep it working optimally.  The oil needs to be changed, the filters have to be replaced, and maintenance checks have to be performed.  I wrote a blog that covers most of these items, “Compressed Air System Maintenance”.

To connect the supply side to the demand side, a distribution system is required.  Distribution systems are pipes which carry compressed air from the air compressor to the pneumatic devices.  Just like the transmission on the car, the power is transferred from the air compressor to your pneumatic products.

Maintenance is generally overlooked in this area.  Transmissions have oil which can be detected if it is leaking, but since air is a gas, it is hard to tell if you have leaks.  Energy is lost from your pneumatic “engine” for every leak that you have.  So, it is important to find and fix them.  A study was conducted within manufacturing plants about compressed air leaks.  They found that for plants without a leak detection program, up to 30% of their compressed air is lost due to leaks.  This will be equivalent to running on only 6 cylinders in a V-8 engine.

EXAIR offers the Ultrasonic Leak Detector to find those pesky leaks.  It makes the inaudible “hiss”; audible.  It can detect leaks as far as 20 feet (6m) away with the parabola attachment, and can find the exact location of the leak to be fixed with the tube attachment.

Another area for discussion with the distribution system is contamination like rust, oil, water, and debris.  Compressed air filters should be used to clean the compressed air that supplies your pneumatic products. They can remove the debris for your pneumatic products to have a long life.  You can read about the EXAIR compressed air filters here, “Preventative Maintenance for EXAIR Filters”.

The third section is the demand side.  So, you have an engine that makes the power, the transmission to transfer that power, and the tires to use that power safely and efficiently.  Many managers miss the importance of the demand side within their pneumatic system.  If you are using blow-off devices like open pipes, coolant lines, copper tubes, or drilled pipe; it will be like running your car on flat tires.  It is very unsafe as well as reducing gas mileage.  To improve safety and efficiency, EXAIR has a line of Super Air Nozzles and Super Air Knives.  Not only will it increase your “gas mileage” to save you money, but they also will keep your operators safe.

In this analogy, you can have a high-performance engine and a durable transmission, but if your tires are bald, flat, or cracked; you cannot use your car safely and efficiently.  The same thing with your compressed air system.  You have to optimize your blow-off devices to get the most from your pneumatic system.  EXAIR is a leader in engineered blow-off devices for efficiency and safety.  So, if you want to improve the “health” of your pneumatic system, you should begin at how you are using your compressed air on the demand side.  EXAIR has Application Engineers that will be happy to help you in trying to keep your pneumatic system running like a “brand new car”.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Photo: Ford Mustang Roadster by openclipart-VectorsPixabay License

Understanding Noise: Sound Power Vs. Sound Pressure

Sound Power and Sound Pressure have been covered a few other times here on the EXAIR Blog. Once here by Brian who made the visual correlation in regards to a speaker and a musical instrument. And here by Russ who breaks down how you calculate sound power level with the below equation!
Sound Power Equation
too lou Sound Power Level Equation
All machines generate sound when they are in operation. The propagated sound waves cause small changes in the ambient air pressure while traveling. A sound source produces sound power and this generates a sound pressure fluctuation in the air. Sound power is the cause of this, whereas sound pressure is the effect. To put it more simply, what we hear is sound pressure, but this sound pressure is caused by the sound power of the emitting sound source. To make a comparison, imagine for example a simple light bulb. The bulb’s power wattage (in W) represents the sound power, whereas the bulb’s light intensity represents the sound pressure.
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Light Bulb
Sound power does not generally depend on the environment. On the contrary, the sound pressure depends on the distance from the source and also on the acoustic environment where the sound wave is produced. In the case of indoor installations for example, sound pressure depends on the size of the room and on the sound absorption capacity of the surfaces. For instance, say the room walls don’t absorb all the sound but reflect parts of it, then the sound pressure will increase due to the so called reverberation effect. (reverberation time is broadly defined as the time it takes for the sound pressure to reduce by 60 dB after the sound emitting source has been shut off). OSHA puts the following limits on personnel exposure to certain noise levels:
Working in areas that exceed these levels will require hearing protection.
EXAIR’s line of Intelligent Compressed Air Products are engineered, designed, and manufactured with efficiency, safety, and noise reduction in mind.  If you’d like to talk about how we can help protect you and your folks’ hearing, call us. Jordan Shouse Application Engineer Send me an email Find us on the Web  Like us on Facebook Twitter: @EXAIR_JS Light Bulb image courtesy of  josh LightWork  Creative Commons License