The system adopts single-beam and dual-wavelength optical path structure

combined with outputs of measurement channel and reference channel

which effectively improves anti-interference ability and measurement precision of system.The system uses a new-type electrically modulated IR light source and a high precision builtin filters pyroelectric IR detector

supported by reasonable air chamber structure design

greatly improve compactness and stability of system.In signal processing

ultra-low power consumption MCU system is adopted for real-time data processing and display.Experimental results show the sensor can accurately detect SF6 concentration in range of 0

2 500 × 10-6

with resolution of 1 × 10-6and measurement precision of 2 % FS.