Mining Contract: Resource Identification for Improvement of Electromagnetic Compatibility (EMC) in Underground Coal Mines

Contract Status & Impact

This contract is complete. To receive a copy of the final report, send a request to mining@cdc.gov.

Electrical and electronics equipment emit electromagnetic energy. These emissions can be either intentional, as in a radio with an attached antenna, or unintentional, as a byproduct of non-radio related operation, such as a digital clock harmonic radiating away from a computer. Unintentional emissions are controlled to protect the ability of radios to receive intentionally generated signals, such as broadcast programs from commercially licensed stations, or signals sent from one handheld radio to another. Intentional emissions are not controlled by electromagnetic interference (EMI) standards, but may be controlled by licensing agencies to promote proper use and sharing of the electromagnetic spectrum. Byproducts of intentional emissions (harmonics and spurs accompanying desired transmissions) are controlled by the Federal Communications Commission.

Due to the increased use of radio-based systems and microprocessor controlled equipment in coal mines, the Office of Mine Safety and Health Research (OMSHR) is interested in identifying available practices, standards, and resources that can be adopted to reduce the potential for electromagnetic interference (EMI). Research performed under this contract identified possible EMI requirements for coal mining equipment to ensure proper operation of equipment used in mines with a view towards maximizing mine safety, and also identified potential commercial resources for improvement of EMC in underground coal mines.

The final report generated from this contract includes an outline of a process to conduct the testing and analysis aimed at determining the proper EMI requirements for coal mining equipment. A fundamental assumption made throughout this report is that the coal mining industry can greatly improve EMC through the use of existing standards, with minimal need for the development of custom EMI requirements. Requirements presently used in various industries and disciplines are examined as to their utility for coal mining equipment. The specifications and standards examined include CISPR, IEEE, ISO, and EN61000.