U.K.-based Trolex Ltd. has developed an intrinsically safe monitoring system designed specifically for underground miner refuge chambers. According to the company, these systems allow miners to check conditions both inside and outside the chamber while awaiting rescue, providing the capability to decide whether it is safer to stay put or begin their escape.
In a fixed refuge chamber system, Trolex employs its Sentro 8 and Sentro 1 integrated monitoring station with intelligent, interchangeable sensing modules. A master Sentro 8 system is located in the main safety chamber to monitor five gases plus temperature, humidity and pressure, and the secondary Sentro 8 system is located outside the chamber to measure four to seven gases plus relative pressure. Within the air lock or transition space before entering the main chamber, two gas detectors measure the levels of oxygen and carbon monoxide. All equipment uses universal data communications with standard Modbus protocol. There are large LCD read-out displays and programmable visual and audible alarms and the entire system is capable of 106 hours operation from a UPS power supply. Trolex also offers the Sentry transportable chamber monitoring system. This stand-alone unit is based on the Sentro 8 integrated monitoring station and features eight monitoring modules for five gases. The self-contained unit has an integral carrying handle and a stainless steel skid-panel base plate.