Drying Desk: Establishing your dry product spec with sampling and analysis
Drying is an important and often expensive step in processing chemicals, pharmaceuticals, foods, paper, and other bulk solids. A drying specification is usually stated as the dry product's maximum residual moisture. [In this context, moisture refers not only to water but to any volatile liquid or liquid azeotrope that remains in the dry product.] Yet measuring this residual moisture and arriving at the drying spec to meet your product requirements at the lowest processing cost isn't always easy.
Sampling the dry product and analyzing the sample's moisture content are critical steps in establishing your product's proper drying spec and validating your drying process. If these steps are done improperly, you can reach the wrong conclusion about the product's residual moisture, overspecify your target moisture [that is, specify a lower moisture than necessary], and fail to produce a high-quality dry product.