Popular Woodworking 2004-04 № 140, страница 67
MUFFS AND PLUGS: PROS & CONS PASSIVE/ACTIVE MUFFS PRO: Both muff types are easy to use, easy to find in the workshop and easy to put on and remove. They also offer different types of fit: tight to the ear or with more ear space (shown at right in close-up). CON: Muffs have a moderate initial cost and you must inspect and replace the earcup seals periodically. They offer more variable Noise Reduction Rating (NRR) values (10-28dB) compared to other devices. Performance is reduced by the wearing of eyeglasses, helmets, visors and hard hats. Active muffs are more expensive and have to be maintained to ensure adequate performance. PLASTIC EARPLUGS PRO: Inexpensive (less than $5/pair), washable, disposable, moderate-to-high NRR values (25-30dB). CON: Don't fit everyone, can be difficult to position properly, easily contaminated, can compact earwax, easy to lose, must watch for hardening or cracking, best if replaced every three to six months depending on amount of use. The depth of insertion significantly affects performance if not installed properly. FOAM EARPLUGS PRO: Inexpensive (less than $2/pair), readily available, comfortable, disposable, available with or without safety cords, moderate-to-high NRR values (25-30dB). CON: Effective for no more than two or three insertions with care, can be difficult to position properly, easily contaminated, can compact earwax, easy to lose. The depth of insertion significantly affects performance if not installed properly. CUSTOM PLUGS PRO: Comfortable, washable, easy to use with instruction, moderate-to-high NRR values (25-30dB). Con: Expensive ($35-$50), can compact earwax, easy to lose, must watch for hardening and cracking, best if replaced every one to two years depending on amount of use. EARCAPS PRO: Inexpensive (less than $10/pair), easy to use, easy to remove and replace with dirty hands, lightweight, comfortable, compact, have washable replacement pods. These are designed for intermittent or short-duration noise exposure. CON: Do not fit all individuals, can be difficult to position properly, can compact earwax, low-to-moderate NRR values (15-25 dB). - CE popwood.com 65 |
