Patent ID: 8660682

Claim:
A system for controlling the temperature in a measurement gap adapted to accommodate a continuous web, having a first side and a second side, that travels in a downstream direction, which comprises: (a) a first sensor head disposed adjacent to a first side of the web, the first sensor head including: a first operative surface facing the first side of the web; means for heating the first operative surface; and means for measuring the temperature of the first operative surface; (b) a second sensor head disposed adjacent to a second side of the web, the second sensor head including: a second operative surface facing the second side of the web, wherein the first operative surface and the second operative surface define the measurement gap through which the continuous web travels, and wherein the measurement gap has a web entry end and a web exit end that is downstream from the web entry end; means for heating the second operative surface; and means for measuring the temperature of the second operative surface; (c) temperature sensor to detect the ambient temperature within the measurement gap and that generates signals representative of the ambient temperature; (d) means for supplying a heated gas at the web entry end such that the heated gas flows continuously into the measurement gap via the web entry end and out of the measurement gap through the web exit end; (e) computing means in communication with the temperature sensor to process the signals to generate a gap temperature profile and that stores a predetermined desired gap temperature profile; and (f) control means in communication with the computing means for controlling the temperature of the heated gas that is supplied, the means for heating the first operative surface, and the means for heating the second operative surface to correct for deviation from the desired gap temperature profile.