Environmental Monitoring System
The Environmental Monitoring System is an intrinsically safe on line telemetry system for continuously monitoring underground coal mine environmental parameters like CO, CH4, Oxygen, Air velocity and Temperature. The major product and components of underground Telemonitoring system are manufactured by M/s, Trolex Ltd., U.K. The system can be broadly divided into three parts, namely:
. Surface Computer System
. Outstation/ Underground Remote Station (URS)
. Sensors and their associated units.
Surface Computer System
The surface computer system consists of Pentium PC (Industrial Grade), Printer, Color Monitor, Interface Unit (Modem) with Barrier and UPS.
Barrier/Isolator
The Barrier/Isolator Unit is designed to provide a certified interface between the hazardous Group I Area and non-hazardous Area. It provides optical isolation between the two Areas and acts as an interface between hazardous area equipments and surface computer.
Outstation/Underground Remote Station
Programmable Sensor Controller (Model –TX9042) acts as the outstation which is a low cost Telemetry unit designed to provide analogue and digital monitoring, pilot circuit interlocking and control. This is an Intrinsically Safe, dustproof and waterproof Unit. It accepts the analogue voltage signal (0.4 to 2.0V) from different sensors. It has an inbuilt RS-485 port which sends this information to the computer via Transmission hardware/Repeater & Barrier/Isolator.
Sensors & Associated Units
The Sensors (CO, Methane etc.) sense the particular parameter and convert them into proportionate analogue voltage signal (0.4 to 2.0 volt). These signals are fed to the Outstation (Programmable Sensor controller), which in-turn convert these signals into digital form and then sends to the surface computer for data logging and display on the monitor.