The testing methods of isolation ear muffs are aimed at determining the protection and comfort levels of the device under varying environmental and working conditions. They need to be supported by a set of guidelines which can evaluate the quality parameters as applicable globally. This can be ensured by applying the ANSI S-3.19 and CE-EN-352.1 standards for the testing processes. The device is subject to tests for evaluating the Noise Reduction Rating, Real Ear Attenuation, fitting perfectness, sound filtering and rear ear protection.
Sound Level Meters for Isolation Ear Muffs
Sound Level meters are installed along with the isolation ear muffs at various points within the testing zones of the laboratory. The source of noise is kept at the center of the laboratory. The testers start generating noise from 64HZ and increase the frequency till 8000HZ.
- The behavior of the protection device is the first parameter to be tested. Here the testers focus on how well the device is capable of deflecting and dampening the intensity of noise within few microseconds of time interval set by them. If the net reduction is more than 84%, the device is given the first phase of approval.
- The time interval between variations in the noise intensity is varied. For example the noise may be increased from 125HZ to 250HZ within two milliseconds. In the next instance it may be increased to 800HZ or it may be decreased to 64HZ. This sort of variation is fairly random in nature.
- By repeating the same set of tests, the testers measure the physical conditions of the isolation ear muffs under different environment conditions. For example they may increase the room temperature, humidity and other variables. The endurance and sound attenuation properties of the ear muffs are tested for various durations of time. All the results are recorded and subject for analysis. The mean attenuation values and standard deviations are also recorded.
User Tests for Isolation Ear Muffs
Similar experiments are conducted by subjecting groups of users to the similar conditions and noise levels. They are made to wear the isolation ear muffs and get exposed to the noise frequencies in the range of 125HZ to 250HZ which may change within two milliseconds. Here the effects of protection on the user ears are tested when the frequency / intensity of the noise is doubled.
- Care is taken to avoid excessive exposure to harmful noise levels. The comfort levels of the users are also subject to test in this method.
- The attenuation values and user comfort levels are recorded at the end of each experiment. The endurance and sound attenuation properties of the ear muffs are tested for various durations of time. All the results are recorded and subject for analysis. The mean attenuation values and standard deviations are also recorded.
The net results from the Sound Level Meter and User testing are sued to evaluate the quality parameters of the isolation ear muffs. ClearArmor 141001 Shooters Hearing Protection Safety Ear Muffs are exposed to some of the toughest tests of this sort. The results have inevitably proved that they belong to the top class of isolation ear muffs.