Revision amendments of AQ 6201 General Technical Requirements of Coal Mine Safety Monitoring System

In order to further play role of coal mine safety monitoring system in gas control, AQ 6201-2006 General Technical Requirements of Coal Mine Safety Monitoring System should be amended. The main contents of proposed amendments include: increasing alarm and power-off locking function of coal and gas outburst, increasing wind direction sensor; allowing the use of optical fiber cable transmission in the system; enhancing sensor protection grade to IP65; dual host computer hot-backup and automatic switch are needed and lightning protection of underground power source is not needed; reducing transmission processing error; error rate of analog input, analog output and cumulative input transmission processing is not more than 0.5%; shortening the maximum inspection cycle of the system, which is not more than 10 s; prolonging record storage time and shortening information missing time; real-time monitoring value of methane and other important monitoring points should be kept for more than 3 months, analog value statistics and records should be kept for more than 2 years; when a system failure occurs, time length of losing above information should be not more than 40 s; shortening response time of extracting picture, response time of extracting 85% of the whole picture is less than 1 s, and response time of extracting the other pictures is less than 2 s; reducing bit error rate, which should not be greater than 10-9; increasing transmission distance from substation to sensor and power supply distance from intrinsically safe power source to substation, the transmission distance from substation to sensor and actuator and the power supply distance should be more than 2 km, or 3 km, or 6 km; shortening switch time of two computers, the time from the host fault to the backup host into normal working should be not more than 40 s; increasing working time of backup power source, when grid is blackout, the backup power source should be able to ensure that the system continuous monitoring time is not less than 3 h; reducing immunity test level, the immunity levels of electrostatic discharge, RF electromagnetic field radiation, electrical transient bursts and surge are the second level; canceling requirements of reliability; monitoring equipments used in underground coal mine must be explosion-proof.