NOISE MEASUREMENT
Noise Measurement,
It is the most common physical factor in noisy work environments. Noise Measurement, which is one of the most frequent measurements among Occupational Hygiene Measurements, comes first.
Before describing the noise measurement, it is necessary to start from the definition of noise.
Noise is defined as distracting unwanted sounds that disturb and disturb.
Noise in working environments is considered to be the sounds that affect workers physiologically and psychologically negatively and decrease work efficiency.
Sound is the vibration of any material, which is absorbed by the ear by moving from the molecules of the environment.
Noise measurement; In accordance with the Labor Law No. 4857 and the Noise Regulation, it is obligatory to do this in workplaces and factories.
Noise measurement should be carried out in two stages as required by the noise regulation. For noise measurements, it should be ensured that all the machines and machines of the facility to be measured are working.
In the first stage, instantaneous noise levels should be measured in all factories or workplaces in accordance with the legislation. In addition to preparing the noise measurement report, the noise measurement points should be shown on the factory layout plan and colored according to the measured value and the noise map should be prepared. The noise map should be hung where all workers can see it and ear protection should be used in noisy areas.
The second stage is the measurement of personal noise exposure. According to the nature of the work, the location of the factory, the machines and the machines, personal noise measurement devices should be installed on the ear collars of the pre-determined workers. The noise meter stays on top of the worker from the beginning of the shift to the end of the shift and performs continuous noise measurement at short intervals. The noise measurement continues between tea and food and accurately measures daily exposure.
As can be seen from the graph in the figure, taking into account the background noise, the peaks of the noise are recorded in the most accurate form of the time interval when the noise is higher. Personal noise measurement according to ambient noise measurement guides the selection of the correct ear protection. In personal noise measurements, the calculation method is far from accurate. Calculating 8-hour exposure according to the noise level within the specified time interval does not give real results, especially in jobs whose noise level changes instantaneously (welding, grinding, cutting, hammer, press, etc.). The measurement of personal noise will be most accurate during the time interval between tea and food during the study.
Noise measurement; It should be carried out with appropriate methods and devices as specified in Article 6 of the Noise Regulation. Noise measurement that is not made in accordance with the correct technique and legislation will render the noise measurement report worthless. Noise levels in the noise measurement report will have no scientific value. As a result of noise measurement, it will prevent proper measures to be taken.
In some sectors, due to the nature and process of the job, the noise measurement result is inevitably above the limit values. In case the noise measurement result is higher than the limit values, the employer should take the necessary measures and measures in accordance with the labor law and noise regulation. The negative effects of noise on human beings and the noise level in the working environment should be analyzed well and embezzled and committed ear dryers should be given to the workers. In accordance with article 10 of the noise regulation, workers should be provided with occupational health and safety trainings on noise measurement results, damages and effects of noise and noise protection methods.
1. Noise
2. Definition, types and sources of noise:
Noise is generally defined as unwanted and disturbing sound.
The noise in the industry can be defined as the voices that leave physiological and psychological effects on the employees in the workplaces and affect the productivity negatively.
If the sound that makes noise is physically defined; Sound is an oscillation event that occurs in a medium of matter, which is caused by the compression and expansion of molecules.
The sound produced by the tuning fork is known as pure sound, that is, compression and relaxation are uniformly spaced in the tuning fork. The sound generated in the tuning fork forms a smooth sinusoidal curve. When we hit the tuning fork, the tuning of the tuning fork again from the deteriorating state of equilibrium is a vibration (one-way), the distance between two consecutive compressions or two expansions is called the wavelength (l), unit; Centimeters. The time taken for a wavelength is called period (T), the unit is seconds. The number of vibrations per second is called frequency (f); 1 / sec. or Hertz (Hz), (fxT = 1 is constant). The product of frequency and wavelength gives the speed of sound (V = fxl). Since it is not enough to know the frequency and wavelength to recognize the sound, it is necessary to know its other features.
This time, let's hit the diapason once strong, once slow. Since the compression and expansion of the tuning fork in the air molecules is different, the sounds we hear are also different. The pressure difference of the atmosphere between pressure and compression and expansion is called sound pressure.
The pressure unit is Bar. The bar is the pressure generated by a force of 106 dynes per square centimeter. Since the sound pressure is very small, one-millionth of a bar is used.
Regarding worker health and work safety, in other words, hearing loss due to noise, it is sufficient to determine the pressure and frequency to recognize the sound. However, since the sound pressure depends on the proximity and distance of the person hearing the sound, the power of the sound must be taken into account. Sound pressure, one meter away from the sound source, is known as the sound power.
Sound power in a unit area is called the intensity of sound, and these intensity levels are called the intensity of sound. In addition, our ears can distinguish two sounds of the same intensity as treble and bass sounds. This feature of sound is called loudness.
The higher the frequency, the higher the sound, the lower the frequency.
It is possible to identify three types of sounds that generate noise. Subsonic sounds are audible sounds and Ultrasonic sounds.
Subsonic sounds; sounds whose frequency is less than 20 Hz.
Audible sounds; approximately 20 Hz. with 20 kHz. sounds.
Ultrasonic sounds; whose frequency is higher than 20 kHz.
Every vibrating object is a sound source. Noise sources in industry; striking type forging, riveting, nailing machines and cutting, crushing and forming machines; liquid and gas repellent effects of pumps, compressors, turbines, fans, jet engines and valves; ignition noises of furnaces and engines; magnetic sounds generated by transformers and dynamos; vibration and friction noises from the gear, motors and machines, etc. d.
3. Effects of noise on human
Noise has two types of physiological and psychological effects on people.
3.1. The physiological (hearing loss) effects of noise on human beings depend on multiple factors. These are:
The intensity of the sound that makes noise,
Frequency distribution of the noise that generates noise,
Time to be affected by noise,
Personal sensitivity to noise,
Age of the subject,
Gender of the subject.
Let's try to examine these factors one by one.
3.1.1. Although the intensity of the noise making noise is important, it is never the main measure alone. Let's examine the relationship between sound and hearing, taking into consideration the intensity of sound.
A healthy human ear is sensitive to sound intensities ranging from 20 µPa to 200 Pa. The ear hears comfortably in this wide range. The sound of 20 şiddetPa is called the hearing threshold, and the sound of 200 Pa is called the pain threshold. The hearing range includes a 107-digit numeric scale. Decibel unit is used to define the sound pressure in this very wide numerical range with a numerical expression in the narrower range.
In practice, the measure of noise is decibel. Decibel is a unit of gain (a physics term) and is a logarithmic expression.
Every three decibel increase doubles the sound, and every ten decibel increase increases the sound ten times.
The volume decreases in proportion to the square of the distance. If the distance doubles, the volume decreases by 6 dB.
20 µPa, 0 dB; 200 Pa corresponds to 140 dB. For this reason, 0 dB in decibels is called as hearing threshold and 140 dB is called as pain threshold.
Noise Level
Location & Location
0 dB.
Hearing threshold.
20 bir A quiet forest.
30 konuşma Conversation with whisper.
40 “Quiet room.
50 bir An office in the city.
60 “Conversation.
70 “Vertical drill.
80 konuşma Speak aloud.
90 “Strong shout.
100 “Weaving halls.
110 “Air hammer, woodworking.
120 “Ball mill.
130 yan Near the planes.
140 “Pain threshold.
3.1.2. A young and healthy human ear with a frequency of 16 Hz. and 20000 Hz. between the sounds. This sensitivity is 60000 Hz in bat, 140000 Hz in dolphin. d. human voices normally under 500 Hz. - 1500 Hz. It is around.
3.1.3. Noise exposure time is a very important factor. The person who has been affected by a long period of severe noise is likely to suffer a great deal of hearing loss.
3.1.4. Being affected by noise shows very different results from person to person. Functional status of the inner ear, previous or existing diseases are important factors in the sensitivity of individuals. However, this factor is not taken into account in the detection of hearing loss.
3.1.5. Age is also an important factor in influencing noise. Especially for the detection of hearing loss age must be taken into account.
3.1.6. Gender is a separate factor in noise impact. However, this factor is not taken into account in the detection of hearing loss.
3.2. Let us briefly summarize the psychological effects of noise on people.
3.2.1. People living or living in noisy environments
- Concentration, attention and reaction capacity weakened,
- Fatigue, sleep disorders, late sleep,
- Central nervous system disorders, headaches and stresses,
- Metabolic and hormonal disorders,
3.2.2. Suddenly, you are under the influence of a loud noise
- Increase in blood pressure (blood pressure),
- Cardio vascular (circulatory) disorder,
- Changes in respiratory rate and
- Increased sweating can be seen.
3.2.3. Noise can also
- Don't shout when you talk,
- Anger,
- Difficulty of mutual agreement,
- Negative relations between people and
- It plays an active role in increasing work accidents.
The most important effect of noise is undoubtedly the hearing loss on people's hearing.
4. Hearing Loss
There are two types of hearing loss in people exposed to severe noise for a long time.
4.1. Conductive hearing loss:
It is a type of hearing loss that occurs in the outer and middle ears. The sound intensity suffers a loss as it passes through the outer and middle ear and is not transmitted to the inner ear. This type of hearing loss occurs as a result of a sudden high explosion damaging the outer eardrum. The same sound may cause irregularities in the ossicles in the middle ear.
4.2. Sensori-Neural hearing loss:
This type of hearing loss is a hearing loss in the inner ear. It is the disruption of the fluid or fibers in the cochlea in the inner ear and hearing nerves not working. This type of hearing loss is more of a hearing loss caused by high intensity and high frequency sounds.
In the industry, people with short exposure to high noise may experience a transient perception hearing loss. If this effect is prolonged, the hearing loss is permanent (permanent) and the ear can no longer regain its ability to lose.
5. Noise evaluation
In industry, hearing loss caused by high noise in workers is an occupational disease. Occupational disease is defined in Article 11 of Law No. 506 as follows.
“Occupational disease: temporary or permanent illness, disability or mental breakdown caused by the insured for a repeated reason or due to the conditions of execution of the job, depending on the nature of the work in which the insured is employed.”
It is stated in the list attached to the Social Insurance Health Transactions Regulation which diseases will be considered as occupational diseases and how long after the actual occurrence of these diseases, the insured will be accepted from the profession.
In the occupational diseases list, these diseases are grouped under 5 groups.
A. Occupational diseases caused by chemical substances,
B. Occupational skin diseases,
C. Pneumoconiosis and other respiratory diseases,
D . Occupational infectious diseases,
[0136] E. Occupational diseases with physical factors.
In the industry, hearing loss caused by noise is a occupational disease which is included in the occupational diseases group due to physical factors.
In the list of occupational diseases in the annex of Social Insurance Health Transactions Regulation; Ürültü In order for noise losses to be considered as occupational diseases, it is necessary to have worked at least two years in noisy work and at least 30 days in jobs where noise intensity is consistently above 85 dB. ” The period of obligation for noise is 6 months.
In industry, noise should be measured and evaluated in the best way. In a workplace, noise level measurements are made with noise measuring devices. Noise measuring devices are designed as ambient dosimeters and personal dosimeters.
In a workplace, the total noise level should be measured and a good frequency analysis should be performed during the eight-hour work. In addition, personal dosimeters should be fitted to the workers who work at the workplace to determine the total noise levels to which they are exposed.
If noise measurements are to be carried out considering the hearing loss, the noise measuring devices should be calibrated to dB (A).
In the noise measuring device, dB (A) represents the values closest to the hearing curve of the human ear.
The human ear hears sounds with certain losses, especially at low frequencies and high frequencies. Sound meters have A, B, C and Linear measuring positions. Scale A was calibrated according to the hearing curve of the human ear. In other words, the measurement in frequency A is the value of the human ear. Scale B is a scale used by telephone companies and C scale is used to measure all voices. In addition, the linear scale in the devices is the scale used when frequency analysis is desired.
6. The methods of protection against noise in a workplace can be listed as follows.
6.1 Technical Protection
Measures to be taken at noise source
6.1.1.1. Replacement of used machines with machines with low noise level,
6.1.1.2. Replace the process that needs to be done with a process that requires less noise,
6.1.1.3. Separation of the noise source.
6.2. Precautions to be taken in a noisy environment
6.2.1. To take adequate precautions against noise and vibration on the ground where the machines are placed,
6.2.2. To put noise prevention barrier between the noise source and the person exposed to the noise,
6.2.3. To increase the distance between the noise source and the person exposed to the noise,
6.2.4. Covering places such as walls, ceilings, floors where sound can pass and reflect with sound absorbing material.
6.3. Measures to be taken in the person affected by noise
6.3.1. Enclosing the person exposed to noise in a well-insulated compartment against sound,
6.3.2. Reducing working time in noisy environment,
6.3.3. Use effective personal protection against noise.
Noise canceling values of ear protectors:
Degree of Reduction
Cotton 5 - 16 dB.
Paraffin cotton 20 - 35 ”
Cotton wool 7,5 - 32 ”
Ear plugs 20 - 45 ”
Headset 12 - 48 ”
6.2. Medical Protection
6.2.1. Those who will work in noisy jobs, audiograms should be taken at work and healthy ones should be employed. it is also conceivable to employ deaf and dumb people at birth in noisy work if adequate measures can be taken against certain accidents.
6.2.2. Ear noisy audiograms should be taken every 6 months for those who work in noisy jobs and necessary measures should be taken in cases of hearing loss.
7. Noise control methods, legal regulations
Noise control starts with a good knowledge of the noise intensity in the workplace. employers need to know what is the noise intensity in the workplace, what problems will be experienced in the workplace at this noise level and how much it will be affected by the problems itself. If the employer does not take adequate measures against noise, the employer will have to pay compensation against the occupational disease that will occur in his / her worker.
Likewise, having sufficient information about the negative effects of noise in the workplace and how the workers themselves will be affected and their physiological and psychological consequences will ensure that noise control methods in the workplace work well. As it is known, the supervision of the workplaces in terms of health and safety conditions in our country is mainly the Ministry of Labor and Social Security, the Ministry of Health and local administrations (Municipalities).
Undoubtedly, the most effective and widespread supervision of these organizations is carried out by the Ministry of Labor and Social Security.
It cannot be said that the inspections carried out by the Ministry of Labor and Social Security by the Labor Inspectors (Technical) attached to the Labor Inspection Board are healthy and scientific in terms of worker health and safety, especially in terms of physical and chemical conditions of the workplaces. Because, Labor Inspectors (Technical) inspections with five senses. However, the best method of knowing the physical and chemical conditions of the workplace is measurement and evaluation.
Regarding noise control in the workplace, in Article 22 of the Occupational Health and Safety Regulation, “Where heavy and dangerous work is not carried out, the noise level shall not exceed 80 decibels. Where jobs are required that require more noisy work, the maximum degree of noise is 95 decibels. However, in this case, workers will be provided with appropriate protective equipment, such as headgear, headphones or ear plugs.. In Article 78 of the same Regulation; Aşağıdaki The following measures shall be taken to protect against the harmful effects of noise;
7.1. During the installation of machines that produce noise in the workplace, the floor of the workplace shall be made with materials and systems that will reduce vibration and sound.
7.2. The walls of the noisy workplaces will be covered with materials that will prevent the reflection of sound and the buildings will be constructed with double doors and double windows. Walls shall be made with soundproof material.
7.3. Where noise cannot be reduced, the provisions of Article 22 of this Regulation shall apply.
7.4. General health examinations of workers who will work in noisy jobs will be performed, especially hearing and degree of hearing, ear and nervous system disease, those who have malfunction in this system and hypertension will not be taken into these jobs. However, those who are deaf and mute by birth can be recruited.
7.5. Periodic general health examinations of noisy workers will be carried out. Those with decreased hearing and any disorders, those with ear and nerve disease, and those with hypertension, who will leave their jobs will be controlled and treated. ”
It is called.
In addition, in terms of health rules, but only seven and a half hours a day or less work to be done in the Regulation of Article 2 XX. It is stated in the işler Works with noise exceeding 85 decibels ”that can be worked for maximum seven and a half hours a day.
8. Noise Measurements
Noise measurements; It is made with noise measuring equipment at source, environment and employee's ear level.
In a workplace, a plan and program is prepared in line with the answer to the question of what to do for noise measurement before measuring noise. In line with this plan and program, noise measurements are made and evaluated.
8.1. Noise measurements at source;
In the plan and program, the target should be health and safety of the employees in the workplace. In line with this objective, the noise level of each noise source in the workplace should be measured. These measurements should be made one meter away from the noise source and at points equivalent to the ear levels of employees. These measurements, according to the continuous and variable noise generated by the noise source; It can be done with noise measuring device or ambient dosimeters that can make instant measurements. Again, these measurements can be made in the form of noises produced by the noise sources individually or by the noise generated by all. In addition, it is useful to create noise maps of working areas to be used in measures to be taken against the harmful effects of noise in noisy environments.
As is known, the noise level is measured in decibels and all evaluations are made with this unit. Decibel is a logarithmic expression. Therefore, the noise level to be measured for each source is not determined by simple arithmetic addition for the value of the noise produced by the sources together. For example: the noise produced by two noise sources at the same time with the same noise levels; It is not 100 dB + 100 dB = 200 dB, but 100 dB + 100 dB = 103 dB.
IN ENVIRONMENT WITH MORE THAN ONE NOISE SOURCES
SOUND LEVELS TO HIGH VOLUME
DIFFERENCE BETWEEN (dB) AMOUNT TO ADD (dB)
0 3.0
2 2.6
3 1.8
4 1.5
5 1.2
6 1.0
7 0.9
8 0.8
10 0.4
12 0.3
14 0.2
16 0.1
Distribution of hearing loss of persons exposed to noise at constant frequency noise of 4000 Hz at years of noise levels of 83, 92 and 97 dB (A).
TIMES THAT CAN BE WORKED MORE THAN A DAY ACCORDING TO NOISE LEVELS WITHOUT ANY PRECAUTIONS
NOISE LEVEL DAILY WORKING TIME
Less than 90 dB (A)
90 dB (A) 8 Hours
92 dB (A) 6 “
95 dB (A) 4 “
97 dB (A) 3 “
100 dB (A) 2 “
102 dB (A) 1.5 “
105 dB (A) 1 “
110 dB (A) 0.5 “
115 dB (A) 0.25 “
More than 115 dB (A)
In terms of the implementation of the Noise Regulation, daily noise exposure levels;
Daily noise exposure level (LEX, 8h) (dB (A) re.20 µPa): Time-weighted average of all noise exposure levels including instant pulsed noise for eight hours of work day.
Weekly noise exposure level The time-weighted average of daily noise exposure levels for a week of five hours of eight hours.
Exposure limit value and exposure effective values; maximum sound pressure.
Exposure limit value LEX, 8h = 87dB (A) and Ppeak = 200 Pai
Highest exposure effective value LEX, 8h = 85dB (A) and Ppeak = 140 Paii
Lowest exposure effective value LEX, 8h = 80dB (A) and Ppeak = 112 Paiii
20 µPa with respect to LEX, 8h = 87dB (A) and Ppeak = 200 Pai 140 dB (C)
L (dB) = 20 log P / Po (noise intensity)
If P = 200 Pa and Po = 20 µPa, L (dB (C)) = 140 dB (C)
LEX, 8h = 85dB (A) and Ppeak = 140 Paii
Related to 137 dB (C)
LEX, 8h = 80dB (A) and Ppeak = 112 Paiii
20 µPa in relation to 135 dB (C)
Highest sound pressure (Ppeak)
C - maximum value of the frequency-weighted instantaneous noise pressure
Regulation Footnote:
: 20 µPa in relation to 140 dB (C)
Related to: 137 dB (C)
: It is taken as 20 µPa with respect to 135 dB (C).
7AXX
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