Requirements_and_Specifications.pdf

Requirements and Specifications Replacement Microphones for Noise Dosimeters

Purpose The purpose of this acquisition is to obtain replacement microphones for MSHA-owned noise dosimeters.

Background Information Noise is one of the most pervasive health hazards in mining. Exposure to hazardous sound levels results in the development of occupational noise induced hearing loss, which is distinguishable from hearing loss associated with aging or with medical conditions. Considerable safety risks arise because workers with noise-induced hearing loss may not hear audible warnings and safety signals. The Mine Safety and Health Administration’s (MSHA) regulations establish exposure level standards that are designed to reduce the incidence of hearing loss by maintaining miners’ exposures at or below the established standard. Reducing the overexposures will ultimately lead to a reduction in the incidence of disease among the current mine workforce. MSHA must be prepared to monitor the working environment of the mines in order to determine if the noise levels are being effectively controlled by the measures utilized by the mine operator. The only means to accomplish the task of monitoring in this harsh environment is through the use of noise dosimeters. When the microphones on the noise dosimeters are no longer fit for use on the noise dosimeter due to factors such as dirt and dust accumulation, breakage, etc., they need to be replaced with new microphones in order to ensure that the noise dosimeter can be calibrated and accurately measure noise.

MSHA Equipment Approval Requirements All equipment that is used in underground gaseous mines must be approved by MSHA as intrinsically safe. When an approval is given for an item, the approval is for the complete unit and any replacement parts must be the same as what was in the original approval. MSHA’s inventories of noise dosimeters have MSHA approval as they are needed to protect against the hazards of methane gas and dust containing volatile matter for use in underground mines. MSHA’s dosimeters that require replacement microphones underground have the following MSHA approval numbers 2G-4007, 18-A040003, and 18-A100008. The replacement microphones for the noise dosimeters must be the same that was originally approved in order to maintain the MSHA approval for MSHA’s noise dosimeters.

Further information about the MSHA approval process can be found at: http://www.msha.gov/TECHSUPP/ACC/ACCHOME.HTM

Specific Requirements

Noise Dosimeter Models MSHA requires replacement microphones for three different models of its currently owned noise dosimeters which are all manufactured by or proprietary to 3M Company. The replacement microphones are needed for the following three models of noise dosimeters: 3M NoisePro, 3M Edge, and 3M/Quest Q-200.

Salient Characteristics The replacement microphones for MSHA’s noise dosimeters shall meet all salient characteristics in this section.

1. NoisePro Class 2 Pendant Microphone brand name or equal

(Manufacturer part no.: 53-867, manufacturer ID: 70-0715-8288-9) Salient characteristics of the brand name product include:

a. Field replaceable microphone designed specifically for use with and fully compatible with the 3M NoisePro model noise dosimeter

b. Class 2 pendant microphone

c. 8.5 mm O.D. shoulder-mounted microphone

2. Replacement ¼” Microphone for Edge Dosimeters brand name or equal

(Manufacturer part no.: 57-309, manufacturer ID: 70-0715-8304-4) Salient characteristics of the brand name product include:

a. ¼ inch prepolarized condenser (electret) field replaceable threaded microphone

b. Designed specifically for use with and fully compatible with the 3M Edge model noise dosimeter

3. Field Replaceable Microphone for Q-200/Q-220P brand name or equal

(Manufacturer part no.: 59-847, manufacturer ID: 70-0715-8301-0) Salient characteristics of the brand name product include:

a. Field replaceable microphone designed specifically for use with and fully compatible with the discontinued/obsolete 3M/Quest Q-

200 model noise dosimeter

b. 8 mm omni-directional ceramic microphone