A Gas Monitoring and Control System in a Coal and Gas Outburst Laboratory

Table 1

Gas threshold and measures.

Degree of risk	Sensor	Gas content threshold	Measure	Monitoring area
Normal	1, 2	CH4 ≤ 0.025%	No measure	Entire laboratory
Danger 1	1	CH4 = 0.025%	Attention and Ventilation 1	Unsafe zone
Danger 2	1	CH4 = 1%	Alarm and Ventilation 2	Unsafe zone
Danger 3	2	CH4 = 0.025%	Alarm and Ventilation 3	Entire laboratory
Danger 4	2	CH4 = 1%	Power off and evacuation	Entire laboratory