NOISE / SOUND LEVEL MONITOR
Real-time Active Indoor Noise Level Monitor
This product was designed to assist the industry with the health & safety regulations act on noise levels in the workplace.
The act specifies that if noise levels are generally higher than 85dB in the work area then staff must wear ear protection. If this regulation is not followed then NIHL (noise induced hearing loss) will occur.
REALTIME ACTIVE NOISE LEVEL MONITOR/INDICATOR
The Noise Level Indicator will alert staff of high noise levels in the immediate area. Noise levels are indicated on different types of displays starting at 67dB (which is still safe) and topping off at 124dB.
There are ten levels of indication in 6dB steps. Indication is done using high bright led's for high visibility in the area of detection, which should not exceed 100sqm (10x10 meters).
By monitoring the Noise Level Display, workers can see when it is no longer safe without ear protection. The most important level of indication is 85dB. If the noise/sound level is higher than 85dB then hearing protection must be worn.
The Noise Level Monitor uses sound sensitive devices to detect the sounds whereafter it is amplified and processed for indication.
When 85dB level is reached + 2 seconds, the blue strobe LED's (or additional strobe units) will flash as long as the level remains at or above 85dB.
Each level from 85dB upwards, has a timer that will start countdown when that level is reached. The timer will count for as long as the sound is at that level, even if it is only for a very short time. The timer will then pause when the level drops below. This pause will last for a timed period (different time for each level) before the timer will be reset back to starting point. Let's take the 85dB level for example. The countdown timer for 85dB is 120 minutes (2 hours). Everytime the noise level is at 85dB or higher, the timer will run, counting down from 120 minutes. Whenever the level drops below 85dB, the timer will stop, at whatever the count is. This count is held for 30 minutes whereafter the countdown timer is reset to 120 minutes. If however the level reached 85dB again during this 30 minute hold time, the countdown timer is again started at the hold time until the level drops below 85dB again. The hold timer will restart again at 30 minutes. This continues until the countdown timer eventually times out to zero, when the audible alarm is generated for 2 - 3 seconds during which the level that timed out is shown on the indicator display.
You will now realise that the Noise Monitor will allow for a total exposure at 85dB for 2 hours before the audible alarm will sound. Following this pattern for all the other levels above 85dB, you may understand that as the level goes higher the timed exposure decreases as well as the reset times. This way the system gives approximately 4 warnings for each level before the maximum allowed exposure is reached per day before NIHL. Remember that the priority goes to the highest level above 85dB, meaning that if the level remains at say 115dB for more than 3 minutes, the warning alarm will sound for the 115dB level long before the 120 minute timer timed out for the 85dB level. You now had 1 more warning associated with all levels. If you now get another warning from say the 85dB countdown timer you add that to the previous warnings for the day. The countdown timers for all levels will be reset everytime the warning alarm is activated.
The system is calibrated on installation using a calibrated sound level meter and a generated sound at preset level.
Basically all that is needed to know is when to use hearing protection, by watching the noise monitor display from time to time. If the blue strobe is on, it is time to start wearing that protection.
Options for the Noise Level Monitors
Remote and data logging or recording version of the Noise Level Monitor (NLM). This new option will allow users to monitor the NLM from a remote location like the office of the health & safety officer located on a different floor. Another option is to record all the levels measured in timed intervals and to enable the user to download the information onto a laptop or pc for analysis. This will alow the user to see a trend or compare stats with other departments or different times of the day in the same area. The information can also be used for the health & safety inspections.
Some information about sound measurement and the ear's response.
The human ear process sounds in a logarithmic manner. This is where the dB measurement comes in. 0db measurement means that there is nothing to hear (absolute silence - threshold of hearing). As sound levels increase, so will the dB measurement. A simple formula can be used to calculate standard dB from a known reference.
dB = 20*log*Vout/Vin. This formula shows that for every 6dB increase measured the sound output voltage doubled. The formula can be extended to power measurement (Watts). It will then be : dB = 10*log*Pout/Pin. This means that for every 3dB increase the sound power (Watts) doubled.
This is similar to how the human ear will process sounds. To the human ear however the sound must increase by about 10dB before it will sound like it doubled in volume. The perceived sounds will have an effect on the hearing ability of the ear as the ear is exposed to these sounds for prolonged periods of time, depending on the level of the sound.
It was determined that any sound below 85dB measured will have no long term effect or damage to the ear. At 85dB one can sustain 8 hours of sound at this level without any damage, thereafter NIHL (noise induced hearing loss) may set in. This NIHL is permanent and is not reversable. Now for every sound level increases of about 5dB, the time that one can be exposed to the sound will half before NIHL sets in. Then there is frequency. The frequency of the sound also determines the level at which the ear will be subject to NIHL. A common measurement of dBA is used to measure the sounds that best represents the response of the human ear. dBA is a measurement that is more sensitive between 200Hz and about 15KHz with some peaks and dips inbetween. The ear is most sensitive in the 1KHz to 4.5KHz range. That is why someone with NIHL may first experience a loss of high frequency hearing normally rolling off above 12KHz and eventually decreasing the frequency response of the ear until no more sound can be processed by the inner ear.
If you need more info or need to purchase any of our Noise Level Monitors or need a customised version designed for your company, then do not hessitate to contact us for more information about the product. We will assist you wherever possible with your requirements.
The act specifies that if noise levels are generally higher than 85dB in the work area then staff must wear ear protection. If this regulation is not followed then NIHL (noise induced hearing loss) will occur.
REALTIME ACTIVE NOISE LEVEL MONITOR/INDICATOR
The Noise Level Indicator will alert staff of high noise levels in the immediate area. Noise levels are indicated on different types of displays starting at 67dB (which is still safe) and topping off at 124dB.
There are ten levels of indication in 6dB steps. Indication is done using high bright led's for high visibility in the area of detection, which should not exceed 100sqm (10x10 meters).
By monitoring the Noise Level Display, workers can see when it is no longer safe without ear protection. The most important level of indication is 85dB. If the noise/sound level is higher than 85dB then hearing protection must be worn.
The Noise Level Monitor uses sound sensitive devices to detect the sounds whereafter it is amplified and processed for indication.
When 85dB level is reached + 2 seconds, the blue strobe LED's (or additional strobe units) will flash as long as the level remains at or above 85dB.
Each level from 85dB upwards, has a timer that will start countdown when that level is reached. The timer will count for as long as the sound is at that level, even if it is only for a very short time. The timer will then pause when the level drops below. This pause will last for a timed period (different time for each level) before the timer will be reset back to starting point. Let's take the 85dB level for example. The countdown timer for 85dB is 120 minutes (2 hours). Everytime the noise level is at 85dB or higher, the timer will run, counting down from 120 minutes. Whenever the level drops below 85dB, the timer will stop, at whatever the count is. This count is held for 30 minutes whereafter the countdown timer is reset to 120 minutes. If however the level reached 85dB again during this 30 minute hold time, the countdown timer is again started at the hold time until the level drops below 85dB again. The hold timer will restart again at 30 minutes. This continues until the countdown timer eventually times out to zero, when the audible alarm is generated for 2 - 3 seconds during which the level that timed out is shown on the indicator display.
You will now realise that the Noise Monitor will allow for a total exposure at 85dB for 2 hours before the audible alarm will sound. Following this pattern for all the other levels above 85dB, you may understand that as the level goes higher the timed exposure decreases as well as the reset times. This way the system gives approximately 4 warnings for each level before the maximum allowed exposure is reached per day before NIHL. Remember that the priority goes to the highest level above 85dB, meaning that if the level remains at say 115dB for more than 3 minutes, the warning alarm will sound for the 115dB level long before the 120 minute timer timed out for the 85dB level. You now had 1 more warning associated with all levels. If you now get another warning from say the 85dB countdown timer you add that to the previous warnings for the day. The countdown timers for all levels will be reset everytime the warning alarm is activated.
The system is calibrated on installation using a calibrated sound level meter and a generated sound at preset level.
Basically all that is needed to know is when to use hearing protection, by watching the noise monitor display from time to time. If the blue strobe is on, it is time to start wearing that protection.
Options for the Noise Level Monitors
Remote and data logging or recording version of the Noise Level Monitor (NLM). This new option will allow users to monitor the NLM from a remote location like the office of the health & safety officer located on a different floor. Another option is to record all the levels measured in timed intervals and to enable the user to download the information onto a laptop or pc for analysis. This will alow the user to see a trend or compare stats with other departments or different times of the day in the same area. The information can also be used for the health & safety inspections.
Some information about sound measurement and the ear's response.
The human ear process sounds in a logarithmic manner. This is where the dB measurement comes in. 0db measurement means that there is nothing to hear (absolute silence - threshold of hearing). As sound levels increase, so will the dB measurement. A simple formula can be used to calculate standard dB from a known reference.
dB = 20*log*Vout/Vin. This formula shows that for every 6dB increase measured the sound output voltage doubled. The formula can be extended to power measurement (Watts). It will then be : dB = 10*log*Pout/Pin. This means that for every 3dB increase the sound power (Watts) doubled.
This is similar to how the human ear will process sounds. To the human ear however the sound must increase by about 10dB before it will sound like it doubled in volume. The perceived sounds will have an effect on the hearing ability of the ear as the ear is exposed to these sounds for prolonged periods of time, depending on the level of the sound.
It was determined that any sound below 85dB measured will have no long term effect or damage to the ear. At 85dB one can sustain 8 hours of sound at this level without any damage, thereafter NIHL (noise induced hearing loss) may set in. This NIHL is permanent and is not reversable. Now for every sound level increases of about 5dB, the time that one can be exposed to the sound will half before NIHL sets in. Then there is frequency. The frequency of the sound also determines the level at which the ear will be subject to NIHL. A common measurement of dBA is used to measure the sounds that best represents the response of the human ear. dBA is a measurement that is more sensitive between 200Hz and about 15KHz with some peaks and dips inbetween. The ear is most sensitive in the 1KHz to 4.5KHz range. That is why someone with NIHL may first experience a loss of high frequency hearing normally rolling off above 12KHz and eventually decreasing the frequency response of the ear until no more sound can be processed by the inner ear.
If you need more info or need to purchase any of our Noise Level Monitors or need a customised version designed for your company, then do not hessitate to contact us for more information about the product. We will assist you wherever possible with your requirements.
PORTABLE SOUND LEVEL MONITORS
a Small range of handheld sound level meters are available. Contact us for more information.
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