Monitoring and Assessment of Cemented Paste Backfill Containing Coal Gangue and Fly Ash in an Underground Mine

Table 2

Parameters of sensors.

Sensor type	Parameters	Figures of sensors
Temperature and humidity sensors	Working voltage: 3–5 V; temperature measurement range: 0°C–50°C; humidity measurement range: 20–100%RH; temperature measurement accuracy 1°C; humidity measurement accuracy: 1% RH; transmission system RS485; transmission maximum distance: 1.2 km
Hydration temperature sensor	Working voltage: 3–5 V; temperature measurement range: −55°C–+125°C; temperature measurement accuracy: ±0.5°C; transmission system: RS485; transmission maximum distance: 1.2 km
Stress meter	Working voltage DC 18 V; working current:≤20 mA; transmission system: RS485; the cross-sectional area of transmission cables: 0.43 mm^2; transmission maximum distance: 1 km; measuring span 0–30 MPa; measuring error: ≤4.0% (FS); main dimension: φ118∗60.5 mm
Displacement meter of CCGPB	Parameters: setting; working voltage: DC 18 V; working current: ≤20 mA; transmission system: RS485; cross-sectional area of transmission cables: 0.43 mm^2; transmission maximum distance: 1 km; measuring span: 0–500 mm; measuring error: ≤4.0% (FS); main dimension: φ186∗3000 mm