Simulation Study on the Impact of Fog Density on Effectiveness of Infrared Thermography

The infrared thermography is a fast, large-scale and non-destructive defect detection technology yet its efficacy in fog weather is still to be studied. This work offers a novel approach to explore the impact of fog density on the efficacy of infrared thermography based on Mie scattering theory by simulating the detecting process where there is fog between the excitation and the sample. A typical radiation fog extinction model was established with Multiphysics simulation software. Based on this foundation, the effect of the level of visibility on the test results was studied. Principal component analysis, fast Fourier transform (FFT) and signal-noise ratio were used to quantify the influence of fog density on the infrared thermography. The simulation results show that the infrared thermography remains excellent detection ability and FFT can greatly improve the detection effect under foggy weather, making the propagation of heat waves in the air no longer the main factor of dragging down the detection effect.