ovendrymenetelmä

The ovendrymenetelmä, or oven-drying method, is a common technique used to determine the moisture content of a sample. This process involves heating the sample in a laboratory oven at a controlled temperature until all free moisture has evaporated. The temperature and duration of drying are critical parameters and are typically specified by standards relevant to the material being tested. For instance, testing methods for wood, grain, or soil will have different prescribed drying conditions.

To perform the ovendrymenetelmä, a sample of known initial weight is placed in a pre-weighed container, often a drying dish. This container with the sample is then put into the oven. After the specified drying time, the sample is removed from the oven and allowed to cool in a desiccator to prevent it from reabsorbing atmospheric moisture. Once cooled, the sample and its container are weighed again. This process of drying, cooling, and weighing may be repeated until a constant weight is achieved, indicating that all moisture has been removed.

The moisture content is then calculated as the difference between the initial weight and the final dry weight, expressed as a percentage of the initial wet weight or sometimes as a percentage of the dry weight. This method is widely used in various fields, including agriculture, food science, and materials testing, due to its simplicity and accuracy when performed correctly. However, it is important to note that the ovendrymenetelmä is not suitable for samples that decompose or change chemically at the required drying temperatures.