A method of density-thickness joint compensation was developed to make the on-line measurement of moisture for moving irregular mineral materials. At the same take

the materials’ thickness

as a weighted factor

was chosen to modify the prompt moisture in a fixed time and improve the accuracy of measuring moisture. The result is in accord with the data of Reference [5]. The experimental data show that the measurement accuracy is better than 5% for a thickness of >2cm and a moisture of >6%. The system has been running on the spot for about three months

with a result accorded with that by the stoving-weighing method.