FSYJ4B methane alarm light blocking voice of the instrument or methane concentration overrun by light as an alarm trigger signal reaches the set value, an alarm will sound, the output control voltage to the detonator, so Exploder lockout, no charge, no output ignition impulse to ensure mine safety, suitable for coal mine. The main technical parameters: Methane measurement range (0.00 to 4.00)% methane measurement error of ± 0.3% methane alarm setpoint 1.00% methane lockout alarm setpoint 1.00% light blocking value 20 ± 5Lx (at 1m distance) operating voltage (7 ~ 8) V DC, by the FD200XS (C) interlock digital remote control detonator, battery-powered operating current of 200mA alarm output voltage <7VDC