MSHA: Gas Detectors, Other Devices May Interfere with Proximity Detection Systems

Published April 27, 2016

​Earlier this month, MSHA notified mine operators that certain devices or equipment may cause electromagnetic interference that adversely affects the performance of proximity detection systems, which use electronic sensors on both mining machines and miners to detect motion or the location of one object relative to another. Proximity detection systems can be programmed to send warning signals and stop mining machines before they injure or kill workers in underground coal mines.

MSHA has found that devices and equipment such as gas detectors, hand-held radios, respirable dust sampling devices, laser range finders, trailing cables, and variable frequency drives may cause interference when they are placed within several inches of the miner-wearable component of the proximity detection system. According to the agency, this interference can disable the protections designed to stop a continuous mining machine before a miner is contacted. Mine operators with a proximity detection system installed on their equipment should identify sources of any electromagnetic interference that affect the performance of the system. MSHA’s notice guides mine operators to place the miner-wearable component of the proximity detection system immediately adjacent or as near as possible to electrical devices or equipment used or worn by miners when making this determination.

Operators who identify any device or equipment that interferes with the proper functioning of a proximity detection system should notify the system’s manufacturer and follow recommended best practices to address the problem. MSHA notes that proximity detection systems should not be used until the interference problem is corrected. Mine operators must continue to comply with existing requirements, including respirable dust sampling, while the interference problem is being corrected.

For more information, see MSHA’s website.