The UM300 microprocessing instrument has been designed to determine on-line the percentage of moisture present in the wood. The material is dried by the heat of an infrared lamp. The method used is unaffected by any side effects which may be caused by colour, density, chemical properties or absorption, all of which may produce unreliable results with other methods. A pneumatic arm extracts the material from the production line and places it in a thermostatic chamber containing a precision weighing scale, where the moisture test will be carried out. When the final weight is reached the moisture content is calculated and displayed. The procedure is performed automatically and does not require an operator.