Abstract: A dryer for the removal of moisture or solvents from fine specialty chemicals and pharmaceuticals after their production, comprises a rotating drying compartment (2) which consists of at least one window (3), in operable relationship with an NIR probe (4) for measuring the moisture content of the product such as a specialty chemical or biological pharmaceutical contained in the closed drying compartment. The NIR probe (4) is positioned outside the drying compartment and is oriented through the at least one window (3) toward the product.

Abstract: A dryer for the removal of moisture or solvents from a product, comprises a rotating drying compartment as shown in FIG. 1 which consists of at least one window (3), in operable relationship with an NIR probe (4) for measuring the moisture content of the product such as a specialty chemical or biological pharmaceutical contained in the closed drying compartment, The NIR probe (4) is positioned outside the drying compartment and is oriented through the at least one window (3) toward the product. method for controlling the dryers' operation further comprising an NIR probe for measuring the moisture of the product being dried without the need for method for controlling the dryers' operation further comprising an NIR probe for measuring the moisture of the product being dried without contacting the product or interfering with the products' removal. contacting the product or interfering with the products' removal.