MICROWAVE APPARATUS AND METHOD FOR ACHIEVING ACCURATE WEIGHT MEASUREMENTS

摘要

The invention is an apparatus and method for obtaining accurate sample weight measurements during sample heating within a heating cavity by substantially reducing the convection currents that disrupt accurate sample weight measurement. The apparatus includes a heating cavity (11) in which a sample (20) can be placed, a source (12) for introducing microwaves into the heating cavity (11), and an analytical balance (13) for measuring the weight of the sample (20) while the sample is in the cavity (11), and an air shield (14) that is secured to the inside of the heating cavity (11) so that the air shield (14) will not contact the analytical balance (13). The air shield (14), which is made of material that is permeable to microwave radiation and yet absorbent of volatiles, is positioned in the heating cavity (11) to reduce the convection current rising from the sample (20) as the sample is heated.