The moisture content of wood is commonly measured using the oven-dry method. This method consists of the following steps:
Weigh the sample of wood then place it in an oven set to a temperature between 214 and 221 oF. Leave the sample in the oven until it is oven dry. This can be determined by weighing the sample then placing it back in to the oven for another 2-3 hours. If no weight has been lost after 2-3 hours, then the sample is oven dry. Once the sample has been oven dried, re-weigh the sample. For determining the moisture content on the oven-dry basis the formula for calculating the moisture content is:
Moisture content (percent) = [( Original weight – Oven dry weight) / Oven dry weight ] x 100
The moisture content of wood can also be determined by using a moisture meter, if the wood is below 30% moisture content. Above 30% moisture content, a moisture meter does not accurately predict the moisture content of wood. There are two basic types of moisture meters, the resistances meter and the dielectric meter. These meters actually measure an electrical property of wood and relate it to moisture content. The moisture content predicted by a meter is influenced by many factors such as: species of wood, moisture content distribution, temperature of the wood, etc. so it is important to follow the manufactures specifications when using a meter.