US 12,000,788 B1
Inline detection of gypsum panel calcination
Eli Stav, Charlotte, NC (US); and Danny Moshe, Ramat HaSharon (IL)
Assigned to Gold Bond Building Products, LLC, Charlotte, NC (US); and MALCAM Ltd., Tel-Aviv (IL)
Filed by Gold Bond Building Products, LLC, Charlotte, NC (US); and MALCAM Ltd., Tel Aviv (IL)
Filed on Jan. 11, 2021, as Appl. No. 17/145,519.
Claims priority of provisional application 62/959,426, filed on Jan. 10, 2020.
Int. Cl. G01N 22/04 (2006.01); C01F 11/46 (2006.01); C04B 11/00 (2006.01); C04B 111/00 (2006.01)
CPC G01N 22/04 (2013.01) [C01F 11/46 (2013.01); C04B 11/00 (2013.01); C01P 2006/82 (2013.01); C04B 2111/0062 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method of determining a free moisture content and/or a degree of calcination of a gypsum panel comprising a gypsum core, a first sheet of facing material, and a second sheet of facing material wherein the first sheet of facing material and the second sheet of facing material sandwich the gypsum core, the method comprising:
(a) transmitting a microwave beam through at least a first portion of the gypsum panel, such that the microwave beam is a transmitted microwave beam;
(b) receiving the transmitted microwave beam to form a received microwave beam;
(c) determining a phase shift and an attenuation from the received microwave beam;
(d) repeating steps (a) to (c) for at least a second portion of the gypsum panel, such that a plurality of phase shifts and a plurality of attenuations is obtained;
(e) using at least one empirical factor to correct the plurality of attenuations, producing a plurality of corrected attenuations;
(f) calculating a raw moisture content of the gypsum panel from the corrected attenuations wherein the raw moisture content comprises a raw free moisture content and a raw crystal moisture content;
(g) using a calibration factor to correct the plurality of phase shifts, producing a plurality of corrected phase shifts; and
(i) calculating a final moisture content of the gypsum panel wherein the final moisture content comprises a final free moisture content and a final crystal moisture content.