HARBOR FREIGHT 58427 Reusable Corded Ear Plugs Instructions
- June 6, 2024
- HARBOR FREIGHT
Table of Contents
HARBOR FREIGHT 58427 Reusable Corded Ear Plugs Instructions
INTRODUCTION
The EPA has selected the NRR as the measure of a hearing protector’s noise reducing capabilities.
Harbor Freight Tools makes no warranties as to the suitability of the NRR as a measure of actual workplace protection since such protection is highly dependent on user training, motivation, and utilization.
A better estimate of workplace protection can be obtained by de-rating the labeled NRR by 50%.
The NRR calculated from this attenuation data is 26 dB. Improper fit of this device will reduce its effectiveness in attenuating noise. Consult instructions for proper fit.
The level of noise entering a person’s ear, when a hearing protector is worn as directed, is closely approximated by the difference between the A-weighted environmental noise and the NRR.
ATTENUATION DATA ANSI S3.19-1974
| Test Frequencies (Hz) | 125 | 250 | 500 | 1000 | 2000 | 3150 | 4000 | 6300 | 8000 | NRR |
|---|---|---|---|---|---|---|---|---|---|---|
| Mean Attenuation (dB) | 33.5 | 30.9 | 36.2 | 34.1 | 36.3 | 41.1 | 40.3 | 41.1 | 45.1 |
26
Standard Deviation (dB)| 5.3| 5.4| 4.9| 4.7| 2.8| 4.1| 4.7| 5.0| 2.4
Example:
- The environmental noise level as measured at the ear is 92 dBA.
- The NRR is 26 decibels (dB).
- The level of noise entering the ear is approximately equal to 66 dBA.
CAUTION! For noise environments dominated by frequencies below 500 Hz, the C-weighted environmental noise level should be used.
The NRR used in the above example was achieved under laboratory conditions.
Although hearing protectors can be recommended for protection against harmful effects of impulsive noise, the Noise Reduction Rating (NRR) is based on the attenuation of continuous noise and may not be an accurate indicator of the protection attainable against impulsive noise such as gunfire.
Wear Instructions
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Make certain that your hands and the earplugs are clean.
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While holding the stem of the ear plug, insert it into the ear canal. You should pull on your outer ear with one hand while you insert the plug with the other.
Insert the plug into the ear canal until all flanges are inside the ear canal. -
When properly inserted, the tip of the stem can be seen by a person in front of you.
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Repeat the above steps for the remaining plug.
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After both earplugs are inserted and are allowed to expand into place, place cupped hands over both ears and compare the sound level. With properly fitted earplugs, you should detect little or no difference in sound level. If the one or both plugs are not fitted properly, readjust the plug(s).
SAVE THESE INSTRUCTIONS.
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