Building materials, wood: Moisture content (NT BUILD 420)

Abstract

SCOPE

This Nordtest method describes a method for measuring the moisture content of wood. Since it utilizes wooden probes with built-in electrodes which are embedded in wooden parts of building constructions where they can be left, it is very suitable for measurements over longer periods.

FIELD OF APPLICATION

The test method is applicable to different wood species as well as to wood-based board materials with known absorption curves. In practice, the use of the method is limited to measurement of moisture contents in the range of approximately 7-28 % (by weight) in wood. At lower moisture contents leakage currents (due to imperfect insulation of wires, plugs, etc.) become dominant – at higher moisture contents the interelectrode resistance varies only slightly with the moisture content. The method is only applicable for measurement in wood which is not under exposure to climatic agents such as sun and rain.