Proximity detection devices affected by interference underground: MSHA

WHILE investigating reports of interference between proximity detection systems and respirable coal mine dust sampling devices, the US Mine Safety and Health Administration has found that other devices or equipment may also cause electromagnetic interference that adversely affects the performance of the PDS.

Lou Caruana

Devices, other than respirable coal mine dust sampling devices, that can cause interference with a PDS include gas detectors, hand-held radios, and trailing cables. Interference occurs when these devices are placed within several inches of the miner-wearable component of the PDS.

This interference can disable the protections designed to stop the machine before a miner is contacted. MSHA is working with mine operators, manufacturers, and the National Institute for Occupational Safety and Health (NIOSH) to identify solutions.

“Due to this additional information and to assure maximum protection for miners, MSHA is notifying mine operators with a PDS installed on any equipment that they should identify sources of any electromagnetic interference that adversely affect the performance of the PDS,” it said.

“In making this determination, mine operators should place the miner-wearable component immediately adjacent or as near as possible to electrical devices or equipment used or worn by miners.”

If a mine operator finds that any device or equipment interferes with the proper functioning of the PDS, the mine operator should notify the PDS manufacturer and follow the manufacturer’s best practices to address the interference problem, MSHA said.

“The PDS should not be used until the interference problem is corrected,” it said.

“In addition, mine operators must continue to comply with existing requirements necessary to protect the safety and health of miners such as respirable dust sampling, communication and tracking, methane monitoring, and other relevant standards while the interference problem is corrected.”