Abstract: Following an elaboration on the significance of using natural-ray ash monitor in the dynamic ash-based coal blending system, the paper presents an introduction to the working principle, functions and most suitable working condition of the monitor, as well as the features of analog outputting, OPC and CANOPEN—the 3 different modes for signal transmission between the monitor and centralized coal blending control system.Field application of the monitor shows that the monitor is safe and reliable in operation with a high measuring accuracy that can meet the requirement of control of ash in coal blending and there is no need for the use of radiation source.It proves to be an important integral part of an intelligent coal preparation plant.