EXAIR offers the model 9104 Digital Sound Level Meter. It is an easy to use instrument for measuring and monitoring the sound level pressures in and around equipment and other manufacturing processes.
Sound meters convert the movement of a thin membrane due to the pressure waves of sound into an electric signal that is processed and turned into a readable output, typically in dBA. The dBA scale is the weighted scale that most closely matches the human ear in terms of the sounds and frequencies that can be detected.
Noise induced hearing loss can be a significant problem for many workers in manufacturing and mining. To protect workers in the workplace from suffering hearing loss OSHA has set limits to the time of exposure based on the sound level. The information in the OSHA Standard 29 CFR – 1910.95(a) is summarized below.
The EXAIR Digital Sound Level Meter is an accurate and responsive instrument that measures the decibel level of the sound and displays the result on the large optionally back-lit LCD display. There is an “F/S” option to provide measurement in either ‘slow’ or ‘fast’ modes for stable or quickly varying noises. The ‘Max Hold’ function will capture and hold the maximum sound level, and update if a louder sound occurs.
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 and myself or one of our Application Engineers can help you determine the best solution.
The CDC (Center for Disease Control) published a useful guide called “Hierarchy of Controls” that details (5) different types of control methods for exposure to occupational hazards while showing the relative effectiveness of each method.
The least effective methods are Administrative Controls and PPE. Administrative Controls involve making changes to the way people perform the work and promoting safe practices through training. The training could be related to correct operating procedures, keeping the workplace clean, emergency response to incidents, and personal hygiene practices, such as proper hand washing after handling hazardous materials. PPE (Personal Protective Equipment) is the least effective method because the equipment (ear plugs, gloves, respirators, etc.) can become damaged, may be uncomfortable and not used, or used incorrectly.
In the middle range of effectiveness is Engineering Controls. These controls are implemented by design changes to the equipment or process to reduce or eliminate the hazard. Good engineering controls can be very effective in protecting people regardless of the the actions and behaviors of the workers. While higher in initial cost than Administrative controls or PPE, typically operating costs are lower, and a cost saving may be realized in the long run.
The final two, Elimination and Substitution are the most effective but can be the most difficult to integrate into an existing process. If the process is still in the design phase, it may be easier and less expensive to eliminate or substitute the hazard. Elimination of the hazard would be the ultimate and most effective method, either by removing the hazard altogether, or changing the work process to the hazardous task is no longer performed.
EXAIR can help your company follow the Hierarchy of Controls, and eliminate, or reduce the hazards of compressed air usage.
In summary, Elimination and Substitution are the most effective methods and should be used whenever possible to reduce or eliminate the hazard and keep people safe in the workplace.
If you have questions about the Hierarchy of Controls and safe compressed air usage from any of the 15 different EXAIR 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.
In the simplest of metric terms, a decibel is one-tenth of a bel. But, historically, bel was a unit created to honor Alexander Graham Bell who invented the telephone. In the early days with telephone wires, they noticed that the signal strength would decay over a long distance. In order to determine power requirements to connect people for communications, they determined that they could use the ratio of power levels. As a start, it had to be based on a minimum amount of power required for a person to hear on the telephone. They found that the signal power level to generate an angular frequency of 5000 radians per second would be that minimum value as determined by an average number of people. They used this mark as a reference point in the ratio of power levels. Because of the large variations in values, they simplified the equation on a base-10 log scale and dividing the bel unit by 10. Thus, creating the measurement of decibel.
Today, this same method is used to measure sound. Like frequency waves that travel through the telephone wires, pressure waves travel through the air as sound. This sound pressure is what our ears can detect as loudness, and it has a pressure unit of Pascals (Pa). As an example, a small sound pressure would be like a whisper while a large sound pressure would be like a jet engine. This is very important to know as high sound pressures, or loudness, can permanently damage our ears.
With sound pressures, we can determine the Sound Pressure Level (SPL) which is measured in decibels (dB). Similar to the equation for the telephone power signals above, the SPL also uses a ratio of sound pressures in a base-10 logarithmic scale. For a minimum reference point, an average human can just start to hear a sound pressure at 0.00002 Pa. So, the equation for measuring sound levels will use this minimum reference point as shown in Equation 1.
L = 20 * Log10 (p/pref)
L – Sound Pressure Level, dB
p – Sound pressure, Pa
pref – reference sound pressure, 0.00002 Pa
Why is this important to know the decibels? OSHA created a chart in 29CFR-1910.95(a) that shows the different noise levels with exposure times. This chart was created to protect the operators from hearing loss in work environments. If the noise level exceeds the limit, then the operators will have to wear Personal Protection Equipment (PPE), or suffer hearing damage. EXAIR offers a Sound Level Meter, model 9104, to measure sound levels in decibels. It comes calibrated to accurately measure the sound to determine if you have a safe work environment.
There is a term that is used when it comes to loud noises, NIHL. This stands for Noise Induced Hearing Loss. Once hearing is damaged, it will not come back. To keep your operators safe and reduce NIHL, EXAIR offers many different types of blow-off products that are designed to decrease noise to a safe level. So, here’s to Alexander Graham Bell for creating the telephone which can be used to contact EXAIR if you have any questions.
Inexpensive air guns can be picked up just about anywhere, and you generally get what you pay for. Most will be very noisy and waste lots of compressed air. And many will be unsafe, violating two of OSHA’s standards put in place to protect worker safety. The first is Standard 29 CFR 1910.95(a) which sets limits to the maximum noise exposure, and the second is Standard 29 CFR 1910.242(b) which says that the nozzle cannot be dead-ended, or exceed a 30 PSIG pressure limit.
These guns may seem like a perfect fit for a handheld blowoff application. The truth is, the cost saved up front will easily be paid throughout the cost of ownership. This is due to the lack of an engineered nozzle which meets and exceeds the OSHA standards mentioned above. The “cheap” guns often have a cross drilled hole to meet or exceed the OSHA standard for dead-end pressure. While this may be true, it causes a large wind sheer which escalates noise levels to well over the allowable noise level exposure set by OSHA. These tips sometimes offer large force outputs because they are equivalent to an open pipe. We have publicized numerous times about how an open pipe blow off does not permit pressure to be utilized all the way to the point of blowoff, and is also a waste of energy.
In order to determine how much compressed air your current blow guns utilize, the level of noise they product, and the sound level they produce, consider taking advantage of the EXAIR Efficiency Lab. The Efficiency Lab is a free service that you can read more about here.
An EXAIR Safety Air Gun is engineered and designed to comply both of the OSHA standards mentioned above, ensuring safe operation for company personnel. On top of the safety designed into the guns, we also ensure all of our guns are efficient by offering only engineered nozzles on them.
EXAIR offers (4) types of Safety Air Guns – the VariBlast, the Soft Grip, the Heavy Duty, and the Super Blast. Each type of Safety Air Gun is offered with a plethora of nozzles, as well as varying length extensions, with or without the Chip Shield.
We invite you to try out an EXAIR Safety Air Gun, and get the free 1″ Wide Flat Super Air Nozzle as a bonus. Click here for more details about this special promotional offer.
From August 1st to September 30th, 2018, EXAIR will be giving away a 1” Flat Super Air Nozzle with the purchase of any promotional VariBlast, Soft Grip, or Heavy Duty Safety Air Gun. EXAIR is stressing the importance of safety in the workplace with the EXAIR Safety Air Guns as well as the versatility of the different types of EXAIR Super Air Nozzles.
This promotional item, the model 1126 1″ Flat Super Air Nozzle, has a patented shim to blow a 1” wide stream of air to clean surfaces quickly and efficiently and is a $45.00 USD value. For more details on the Promotion, click on the photo/link above. For more information about the Flat Super Air Nozzles, click HERE.
Inexpensive air guns can be purchased just about anywhere- online, via catalogs, and through industrial supply companies. Typical quality is less than ideal – broken triggers, leaky valves – a short lifespan in an industrial setting are merely a few of the issues observed. Most are loud and inefficient – they just blow large amounts of compressed air, and at noise levels that violate OSHA requirements. Some may even generate dangerous dead end pressure situations that that can result in serious or fatal injuries if blocked.
EXAIR’s Safety Air Guns have been engineered and designed to eliminate these issues. They are durable for use in industrial situations and comfortable to use for extended periods of time. With an EXAIR engineered air nozzle, each model provides top performance by entraining large volumes of surrounding air into the air-stream. Operation is assured to be safe along with low compressed air consumption and noise levels. Due to the design, the airflow that exits the nozzle cannot be blocked, as required by OSHA Standard 29 CPR 1910.242(b).
The VariBlast style of safety air gun offers variable force based on the range of trigger pull. Force can be varies, form a light breeze, to full force maximum output. This cast aluminum air gun can be fitted with any of the EXAIR 1/8 NPT engineered air nozzles.
The Soft Grip style of safety air gun has a durable cats aluminum body suited for rugged, industrial use. The ergonomic design has a soft vinyl cover, a large trigger for easy operation, and a hanger hook for easy storage.
The Heavy Duty style of safety air gun is powerful with a durable aluminum cast body and ergonomic composite rubber grip, best suited for rugged industrial environments. Hours of fatigue free operation are possible.
With all of the Safety Air Guns styles, Chip Shields and Extension Pipes are available, from 6″ to 72″ in length.
With many nozzle options, from a whisper quiet 58 dBA and 2.5 SCFM of flow up to 60 SCFM and 87 dBA (still below the OSHA 8 hour noise level threshold) there is a model that will fit practically any application. Application Engineers are available by phone, email, and chat to review your specific blow off needs, and help to select the best possible solution available.
We invite to you to try out an EXAIR Safety Air Gun, and get the free 1″ Wide Flat Super Air Nozzle as a bonus.
Keeping noise levels in check and at safe levels is very important to ensure employee safety and well being. OSHA (the Occupational Safety and Health Administration) through standard 29 CFR-1910.95(a) has studied the situation and set Maximum Allowable Noise Exposure limits in Hours per Day based on the Sound Level, in dBA, of exposure.
For existing processes, a Digital Sound Meter is a valuable tool to measure the sound level to ensure that the source of loud noises can be quickly identified and isolated for immediate corrective action.
For new processes, or changes to an existing process, it is important to estimate the sound level prior to installation and start-up, so that precautions can be taken as needed.
For example, let’s say we are going to add a blow off station to clean off a part on a conveyor to improve the process and increase the throughput. A typical set-up might be a 12″ Super Air Knife (model 110012) blowing off the top and a pair of Super Air Nozzles (model 1100) to blow off the sides.
If we look at the performance data for the (2) different blow off devices, we find that the Super Air Knife is rated at 69 dBA and the nozzles at 74 dBA, when operated at 80 PSIG of compressed air supply.
When asked, “what is the sound level for (1) of the knives, and (2) of the nozzles” a little Acoustic Engineering is in order. The decibel scale is logarithmic, and determining the total sound level when all (3) devices are in operation is not as easy as adding up the three sound level values (which would equal 218 dBA, way off the charts!). Thankfully, both the actual sound level and the numerical value are determined another way. I’ll spare you a lot of the math but the equation is as below.
… where SL1, SL2, SL3, … are the sound levels in dBA of the each sound makers, for as many that are being combined (in our example SL1 = 69, SL2 = 74 and SL3 = 74)
Plugging in the numbers into the equation, the combined sound level works out to be a quiet 77.65 dBA — well within the OSHA limit for exposure for a full 8 hour period.
Early one morning I was on a flight to the West coast to start up a system that I had designed and built for a large food producer. After the flight attendants had passed out our first beverage and snack I struck up a conversation with the passenger next to me. We engaged in the typical banter about how hilarious it is to watch some passengers try to stuff an oversized bag into the overhead compartment and ultimately have to check it.
I then asked the reason for her trip and she explained that she worked for OSHA and had conducted a study on flight crew safety and was in route to give her report on the findings. I was naturally intrigued and asked her what the risks were for a flight crew other than the obvious perils of being 35,000 Ft. above the ground for long periods of time.
Her reply was radiation exposure from the sun! I had never considered that flight crews spend long periods of time above the thickest layer of our atmosphere. Flight crews are exposed to significantly greater amounts of radiation compared to us folks who are on the ground more and consequently develop certain health conditions at a higher rate than the general population.
This standard is concerned with the level of noise that personnel are exposed to over a given period of time. Often times in plants compressed air noise exceeds the OSHA noise level requirements which unfortunately results in hearing loss. Noisy air blow-offs can produce noise in excess of 100 dBA. Studies have proven that noise levels that are sustained for varying periods of time can ultimately result in permanent hearing loss. Similar to the way flight crews are exposed to the radiation, some employess may not realize they are being exposed to a harmful level of noise from compressed air usage. This is why OSHA generated the standard that has allowable limits for sustained noise levels in order to mitigate the risks for personnel in the area. Utilizing EXAIR Super Air Nozzles the noise can be reduced to only 74 dBA. EXAIREngineered Air Nozzles reduce the noise without losing the hard hitting force.
EXAIR also meets OSHA Standard 29 CFR 1910.242(b) for “Dead End Pressure”. This standard addresses how dangerous compressed air can be when the outlet pressure of a hole, hose or open pipe is higher than 30 PSIG (2 Bar). If the opening is blocked (dead-ended) into any part of the body, air could enter the bloodstream through the skin. This may result in serious injury. All EXAIR Nozzles and Jets are designed for safety and can’t be dead-ended into the skin therefore can be safely operated above the 30 PSIG (2 Bar) limit.
If you would like to discuss noise levels, dead end pressure or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.