The influence of coal thickness change on dual-energy gamma-ray ash gauge reading

For continuous measurement of coal-ash on a moving belt, intensity averaging causes the derived ratio of low-energy-gamma attenuation coefficient to that of high energy to be smaller than its real value. The difference is related to coal thickness and ash value and it is too great to be neglected. To reduce this thickness change related error, a count-rate level connected sampling method is suggested and its performance is verified by Monte-Carlo simulation.