Moisture measurement by infrared absorption is gaining acceptance in many industries as a rapid, contactless technique which can cover a wide range of moisture values. Following laboratory investigations, Sira Institute has conducted several applications exercises demonstrating the on-line performance of the technique on a number of materials. For granular materials it is common practice to use a backscatter technique. The instrument can be mounted to view material as it passes on a conveyor belt and data obtained during on-line calibration trials on clay dust, sand, iron ore and coke, etc will be presented, together with installation details. In some plant applications the material can be viewed as it passes a window. The wetting up of peat in a mixer, and the drying of straw, are two such applications which will be described. In the above cases, information on the control systems employed and the financial savings resulting will be given. Certain materials such as iron ore, coal, are opaque to infrared radiation and investigations have shown that the infrared reflectance technique then responds to the thickness of the water film around the particles. For certain processes, such as pelletising and pressing, it is believed that water film thickness is the parameter which determines optimum process conditions.