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About IES | |
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IES 2000
For detailed product specs see our NEW site at http://www.artusaindustries.us Team
IES is committed to enhancing the living and working environment by
reducing human exposure to the harmful effects of noise, mist, dust, and
smoke. It is our
goal to be an effective, responsible, and profitable company by meeting
and or exceeding our customers expectations with timely, quality, cost
effective solutions. Our team is a family of customers, vendors, partners, and employees. The ABC’s of NoiseAbsorb
(IES
Absorber Products) Sound absorbers are soft, porous, open-celled materials such
as foam sheets, curtains or blankets and baffles that reduce the reflection of
sound waves. A “NRC”
number-Noise Reduction Coefficient rates their sound absorption
efficiency. The HIGHER the NRC rating, the more EFFICIENT the product is
at absorbing noise.
Barrier
(IES Blocker Products)
Noise Barriers combine mass, flexibility and limpness to
block noise from t transmitting from one area to another.
Flexible mass-loaded vinyl sheeting has replaced thin lead sheets
as the noise barrier of choice. Noise Barriers are rated by a
“STC” number- Sound Transmission Classification.
The HIGHER the STC rating, the more EFFICIENT the product is at
blocking noise.
Composite
Acoustical Composites are products that combine
both Noise Barrier & Sound Absorber materials.
Typically, they offer the most significant overall noise
reduction. Acoustical
Composites are rated in both “NRC” and “STC” numbers Damping Damping materials are paint on or sheet materials
utilized to reduce structure-born noise and resonant vibration.
They are designed to take the “ring” out of sheet metal or
ductwork or similar radiating surfaces.
*NRC is a sound absorption rating. It
measures a percentage of how much sound will not be reflected back from
where it came. Based on a
range from .05 to 1.0, where a NRC of 1.0 means that all the sound
energy that hits that product passes thru it and does not bounce back to
its source. A NRC of .60
would reflect 40% of the sound back to the source, and let 60% of the
noise passthru it. |
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NEWS and Applications
Moulder noise and dust get busted - New ALL ACCESS aluminum and steel systems for generators and pumps - Bagger noise gets bagged - Conference room conversations stay in the conference room - PEA Hosting a big success - Aluma-A-Frame improvements - Successful hybrid application - Great Show in Atlanta - Improvements on our 2 story system
Before 85-90dBA After 75-80dBA
No more noisy blower. No more noisy chiller next door.
http://www.artusaindustries.us
New hybrid systems technology by IES 1/4 the weight, twice as effective acoustically, easier to operate and more cost effective.
More units roll out of the fulfillment center
Gas Compressor enclosures
Power Generation enclosures
IES is ally to the Navy and Marines -3 Day installation makes for a better testing and speaking environment for NAS The addition of sound absorbing baffles not only cut reverb in half and reduced the ambient noise by 5dB it actually brightened the area reflecting more light from windows and fixtures.
OSHA Gets Serious About Hearing Loss (Proposed new regulations for 2003)
by James L. Nash
Why do experts in government and out in the field
expect a huge rise in OSHA recordables for hearing loss this year? Jim Weaver,
senior risk control administrator at Hallmark Cards, has an answer to that
question.
Last year, out of approximately 5,000 employees at
its Kansas City, Mo., headquarters complex, Hallmark had just one recordable
case involving a standard threshold shift (STS) of 25 decibels (dBs).
Weaver said that if OSHA's revised record keeping
rule, scheduled to take effect Jan. 1, were in place today, he would be looking
at 28 recordable cases of occupational hearing loss. That's because the revision
requires employers to record a change in hearing threshold of just 10 dB,
averaged at 2,000, 3,000 and 4,000 hertz. Hallmark is in the process of
gathering more data on hearing loss, and the company will soon
make moves to strengthen its hearing conservation program (HCP).
Many safety and health professionals agree with
Weaver's assessment of what OSHA's new definition of STS will mean. John Franks,
chief of the hearing loss prevention section at the National Institute for
Occupational Safety and Health (NIOSH), foresees a "huge spike" in
hearing loss recordables across the nation as the revised recordkeeping
standard goes into effect , in part because many companies have not
been recording hearing loss at all.
In view of OSHA's more stringent definition of STS,
which is coupled with a new column on the Form 300 just for hearing loss, some
safety and health managers are taking another look at their hearing protection
efforts. That is a good idea, according to one leading NIOSH researcher who
believes too many worksites have no HCP, while other programs are not working
nearly as well as they should be.
"There are some programs that look good on
paper, but when you look at their records, it seems like they're just
documenting hearing loss," said Carol Merry, a NIOSH specialist in hearing
loss prevention.
Merry and other experts believe they know why so many
programs are failing: Workers are not wearing hearing protection devices.
"The fundamental problem here is that hearing
conservation programs have been viewed as something done for the worker,"
said Lee Hager, executive vice president of James, Anderson & Associates, a
hearing loss prevention consulting firm in Lansing, Mich. "Workers never
took this on as their own personal responsibility. They see it as 'something
management does for me.'"
In her research, Merry encountered a good deal of
resistance to the wearing of hearing protectors because they are seen as
uncomfortable and inconvenient. In addition, workers sometimes argue that these
devices represent "the easy way out" for management. Merry found many
workers who complained and would say, "Instead of trying to make the
worksite quieter, they just throw these hearing protectors at us."
Although noise controls are generally preferable to
hearing protectors, these controls are not always practical and carry with them
their own set of problems. Elliott Berger, senior scientist in auditory research
at E-A-R in Indianapolis, argues it is often difficult to achieve 10 dB of noise
reduction with a retrofit noise control application. Ten dB is what the better
kinds of hearing protector devices (HPDs) can provide when used properly.
Most engineering controls require maintenance and
periodic adjustment to remain effective. These problems can be avoided by
cutting noise at its source through redesigning equipment, or "buying
quiet," but this solution is not always feasible.
Still, Merry's research suggests that for a company
to have an effective HCP, it should at least make an effort to reduce noise and
to communicate this effort to workers.
A substantial body of research has established the
various elements needed to have a successful HCP, according to The
Encyclopedia of Occupational Health and Safety. In an article published in
this resource, Larry Royster, a professor at North Carolina State University,
and Julia Doswell Royster, president of Environmental Noise Consultants in
Raleigh, N.C., organized this research into a checklist of good HCP practices.
Included in this checklist are five phases of an
effective program:
The Roysters' research indicates that the best
strategy for making these five phases work together is to unite them under the
supervision of one "key individual" who oversees the entire HCP. They
note that one of the problems at large companies is that too many staff members
become involved in the HCP, leading to a fragmentation in the effort.
The choice of the key individual can be critical to
the success of the program. The Roysters contend that genuine interest in
hearing protection is the most important qualification for this position.
Keeping accurate records of sound surveys and hearing tests, and doing regular
program evaluations are important functions for the key individual.
The five phases of a good program listed above can be
seen as a kind of "chain" of protection, but the entire HCP may be
only as strong as the weakest links in that chain -- workers who are not using
hearing protection.
There are signs that the safety and health community
is forming new alliances and taking bold steps to attack the problem.
In February 2000, the National Safety Council (NSC)
and NIOSH collaborated on two publications that feature hearing protection.
The material was largely the result of research of
Merry and Mark Stephenson, a research audiologist at NIOSH. NSC distributed
95,000 copies of "Today's Supervisor" and 42,000 copies of "Safeworker,"
according to Todd Briggs, NSC's government relations program specialist.
Briggs explained that NSC signed on to the
unprecedented project because it was clear "people weren't getting the
message about hearing loss."
Hager thought the joint effort was on target.
"Strategically, this is exactly the right thing to do," he said. The
reason HCPs often do not work, according to Hager, is because workers have not
internalized the value of protecting their hearing. "The attempt to
communicate these issues of risk and appropriate self-protection to the workers
and to their first-line supervisors is absolutely key to effectiveness."
"Today's Supervisor" states that, no matter
what kind of HPD is used, employees' acceptance and use of hearing protection
depends on four Cs:
Comfort is the No. 1 concern voiced by employees,
according to the authors. No one is going to wear anything for hours at a time
if it is uncomfortable. Because of individual differences, employers must make a
range of sizes and models available.
Joe Durst, director of field services and
communications for the United Brotherhood of Carpenters, agrees. "You can't
just have a one-size-fits-all hearing protector, hand it out and have it
work."
Fortunately, there are more than 200 HPDs marketed in
the United States, ranging from disposable earplugs to custom electronic
earmuffs. Yet, according to Merry, the crucial importance of letting workers
choose their HPDs is a message many employers have simply failed to hear.
"I can't tell you how many places we've been to
where there's just one option -- a box of earplugs," she said.
Allowing workers to have a hand in choosing their
HPDs has another advantage: It increases their sense of participation in
protecting their hearing, making it more likely they will take the time and
trouble to wear the devices.
This gets at two of the other Cs: communication and
cost. Because we are social beings, workers will want HPDs that allow them to
exchange comments with co-workers from time to time. The answer here is to find
protectors that block out noise but do not overprotect.
According to NIOSH's Stephenson, the most important
message of the booklet is captured by "cost," which means letting
workers know the cost of not protecting their hearing.
"I wish I had a nickel for every time I heard
someone say, 'My Dad lost his hearing, and I will too," he said. "For
the average worker, there's no reason to have a hearing impairment."
"What's important about the new Form 300, as
compared to the 200, is hearing loss is recorded as a separate entity in column
6. Before, it was lost under 'physical agents' or 'repetitive exposures,'"
explains John Franks, chief of the hearing loss prevention section at the
National Institute for Occupational Safety and Health.
After a big uptick in 2002, Franks expects to see
numbers concerning hearing loss that mean something. Over time, this will reveal
which hearing conservation programs (HCPs) are effective.
The Bush administration is reviewing all regulations
issued in the final days of President Clinton, including OSHA's recordkeeping
standard. OSHA officials could not comment on the rule, nor confirm that the new
rule will, as expected, take effect next year.
Jim Weaver of Hallmark Cards is not waiting to find
out. Hallmark goes beyond OSHA regulations by implementing its HCP at 83
decibels (dBs) instead of 85. In some Hallmark facilities, employees are
required to wear hearing protection devices (HPDs) at 83 dBs. Weaver is
assessing the situation and thinks the company will move in the direction of
requiring all of its workers to wear HPDs at lower noise levels. He said he will
also explore noise engineering solutions.
Despite the possible need to make these adjustments,
Weaver said, he welcomes the new standard because it simplifies the burden of
recordkeeping.
Marcia Kram, CIH, is a specialist in hearing
conservation at Air Products and Chemicals, based in Allentown, Pa. She agrees
with Weaver that the new rule will lead to a significant increase in recordable
cases of hearing loss. Kram oversees a program with approximately 4,000 workers
in plants around the country. Like Weaver, she welcomes the new rule because it
will make recordkeeping easier.
"I'm glad they got rid of the 25 standard
threshold shift (STS), so now there's just one number we have to keep track
of," she said. Because some state programs required follow-up when a worker
had an STS of 10, Kram had to keep two databases for every worker to keep track
of both STSs. "It was very confusing to the people in our plants who had to
manage this program," she said.
Kram is not anticipating any major changes to her HCP
at this point, but added that "we will be monitoring the program very
carefully in the months ahead because of the recordkeeping requirements."
One part of her program that Kram said has proven to
be quite effective is the practice of conducting hearing tests on site at the
larger plants. Doing this means less lost time for the company and cuts down on
the number of inaccurate tests. Kram said that, with onsite testing, any time an
STS of 10 or more is detected, the worker can be re-tested at once to confirm
the result.
Because an STS of 10 now means an OSHA recordable, making sure the audiometric test is accurate is more important than ever.
SIRKANKEL, Afghanistan -- The al-Qaeda mortar position to the west of Alpha Company wasn't just dangerous, it was annoying.
The four al-Qaeda fighters
there knew their business. As soon as they heard the sound of incoming U.S.
aircraft, or the bang of Alpha Company firing a mortar in their direction, they
would run from the ridge to take cover, reappearing after the U.S. ordnance had
landed. Then they'd wave defiantly and send a shell Alpha Company's way.
Knowing that if any of the
al-Qaeda rounds found their targets, he could lose several of his 100 soldiers,
Capt. Kevin Butler needed a plan.
''I was trying to come up
with a way of sneaking the round in quietly,'' he said later. He settled on an
approach. The captain ordered Sgt. Corey Daniel to call in an airstrike.
Butler told his mortar crews
to fire several rounds at the moment they heard an explosion from the close air
support. ''I thought maybe we could mask the sound of the 60mm mortars firing
with the sound of the close air support,'' he said.
As the booms from the Air
Force bombing echoed across the valley Sunday, Butler's crews went to work.
''The boys were just hanging
rounds like nobody's business,'' Butler said. Seven rounds flew toward the
ridgeline. It would take them about 30 seconds to reach the target. Watching
through his binoculars, Daniel saw the four al-Qaeda troops reappear. The
deception must have worked. As they taunted the American troops, all seven
rounds came down on the al-Qaeda fighters. All four are surely dead.
When faced with a decision always ask "What would be the most fun?"
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The information provided in this part of our website is presented in an effort to help you understand acoustics (the science of sound) and how it affects you in everyday life. Knowing the basics of sound and noise control will help you select products and methods to better solve your acoustical problems. As always, you may contact one of our sales representatives by phone at 1-888-454-6975 or by email at ies2000fa@aol.com to answer your questions and help you build a solution that best fits your needs. IES Glossary of Noise Control Terms ABSORPTION. A property of materials that allows a reduction in the
amount of sound energy reflected. The introduction of an absorbent into
the surfaces of a room will reduce the sound pressure level in that room
by not reflecting all of the sound energy striking the room's surfaces.
The effect of absorption merely reduces the resultant sound level in the
room produced by energy that has already entered the room. ACCEPTABLE SOUND LEVELS
AMBIENT NOISE. The total of all noise in the environment, other than
the noise from the source of interest. This term is used interchangeably
with background noise. A-WEIGHTED SOUND LEVEL. A measure of sound pressure level designed to
reflect the acuity of the human ear, which does not respond equally to
all frequencies. The ear is less efficient at low and high frequencies
than at medium or speech-range frequencies. Therefore, to describe a
sound containing a wide range of frequencies in a manner representative
of the ear's response, it is necessary to reduce the effects of the low
and high frequencies with respect to the medium frequencies. The
resultant sound level is said to be A-weighted, and the units are dBA.
The A-weighted sound level is also called the noise level. Sound level
meters have an A-weighting network for measuring A-weighted sound level. CALIBRATOR (ACOUSTICAL). A device which produces a known sound
pressure on the microphone of a sound level measurement system, and is
used to adjust the system to Standard specifications.
DIFFRACTION. A modification which sound waves undergo in passing by
the edges of solid bodies.
HAIR CELL. Sensory cells in the cochlea which transform the
mechanical energy of sound into nerve impulses. fundamental it is called the second harmonic, etc... IMPACT SOUND. The sound produced by the collision of two solid
objects. Typical sources are footsteps, dropped objects, etc., on
an interior surface (wall, floor, or ceiling) of a building. reference quantity, and the kind of level must be specified. NEAR FIELD. The sound field very near to a source, where the sound pressure does not obey the inverse square law and the particle velocity is not in phase with the sound pressure. NIOSH. The National Institute for occupational Safety and Health. NOISE, 1. Unwanted sound. 2. Any sound not occurring in the natural environment, such as sounds emanating from aircraft, highways, industrial, commercial and residential sources. 3. An erratic, intermittent, or statistically random oscillation. NOISE ISOLATION CLASS. (NIC). A single number rating derived in a prescribed manner from the measured values of noise reduction between two areas or rooms. It provides an evaluation of the sound isolation between two enclosed spaces that are acoustically connected by one or more paths. NOISE LEVEL. For airborne sound , unless specified to the contrary, it is the A-weighted sound level. NOISE REDUCTION (NR). The numerical difference, in decibels, of the average sound pressure levels in two areas or rooms. A measurement of "noise reduction" combines the effect of the sound transmission loss performance of structures separating the two areas or rooms, plus the effect of acoustic absorption present in the receiving room.
NOISE REDUCTION COEFFICIENT (NRC). A measure of the acoustical
absorption performance of a material, calculated by averaging its sound
absorption coefficients at 250, 500, 1000 and 2000 Hz, expressed to the
nearest multiple of 0.05. PERIOD. The duration of time it takes for a periodic wave form (like
a sine wave) to repeat itself. described statistically by probability distribution functions giving
the traction of the total time that the magnitude of the noise lies
within a specified range. REVERBERATION TIME (RT). The reverberation time of a room is the time
taken for the sound pressure level to decrease 60 dB from its
steady-state value when the source of sound energy is suddenly
interrupted. It is a measure of the persistence of an impulsive sound in
a room as well as of the amount of acoustical absorption present inside
the room. Rooms with long reverberation times are called live rooms. ROOM SOUND PROPAGATION Indoor
SONE. The unit of measurement for loudness. One sone is the loudness
of a sound whose loudness level is 40 phons.
Loudness is proportional to the sound's loudness rating, e.g., two sones
are twice as loud as one sone. SOUND INTENSITY, power per unit area, vary substantially with distance from source, and also diminish as a result of intervening obstacles and barriers, air absorption, wind and other factors. The intencity from a source pasing a spherical surface around the source can be expressed as
In a progressing leveled wave the intensity can be expressed as
where
Sound intensity expressed in dB
where
The normal reference level is 10-12 W/m2.
SOUND POWER. The total sound energy radiated by a source per unit time. The unit of measurement is the watt. Sound power levelSound power level are connected to the sound source and independent of distance. Sound power are indicated in decibel.
where
The normal reference level is 10-12 W which is the lowest sound persons of excellent hearing can discern. Note that older american litterature may contain sound power level data referenced to 10-13 W.
Since sound measuring instruments respond to sound pressure the "decibel" is generally associated with sound pressure level. Sound pressure level quantify in decibels the intensity of given sound sources. Sound pressure level vary substantially with distance from source, and also diminish as a result of intervening obstacles and barriers, air absorption, wind and other factors. Since I = p2 / r c then
where
The usual reference level po is 20x10-6 N/m2. Note that the noise from fans, machines etc. in general are documented in sound power level. If the sound pressure
doubles, The lowest sound level that people of excellent hearing can discern has an acoustic sound power about 10-12 W, 0 dB The loudest sound generally encountered is that of a jet aircraft with a sound power of 105 W, 170 dB
of the interfering noise in the most important part of the speech
frequency range. The levels in octave bands centered at 500, 1000, and
2000 Hz are commonly averaged to determine the speech-interference
level. THRESHOLD OF AUDIBILITY (THRESHOLD OF DETECTABILITY). The minimum
sound pressure level at which a person can hear a specified frequency of
sound over a specified number of trials. transmission systems or media. Examples are microphones,
accelerometers, and loudspeakers. WINDSCREEN. A porous device used to cover the microphone of a sound level measurement system which is designed to minimize the effects of winds and wind gusts on the sound levels being measured. Typically made of open cell polyurethane foam and spherically shaped.
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