Health Monitoring System with Hybrid Laser Sensor Networks and Cloud Computing for Subway Tunnels

Table 6

Comparison of sinking values measured with the infrared laser rangefinder and pull-wire sensor.

Load force	Target	Displacement Z (m)
		Infrared laser rangefinder	Convergence meter
Point 1 50 N	No. 1	−0.003	−0.004
	No. 3	−0.003	−0.003
Point 1 100 N	No. 1	−0.005	−0.006
	No. 3	−0.005	−0.005
Point 2 50 N	No. 1	−0.001	−0.001
	No. 3	−0.007	−0.006
Point 2 100 N	No. 1	−0.002	−0.002
	No. 3	−0.011	−0.011
Point 3 50 N	No. 1	−0.005	−0.006
	No. 3	−0.001	−0.001
Point 4 100 N	No. 1	−0.009	−0.010
	No. 3	−0.002	−0.003