Patent ID: 6264362
Filing Date: 2001-07-24
Classification: G01K

Abstract:
Apparatus for measuring heat flux in a tunnel oven comprising conveying means to convey through the oven material to be heated and containing a gas which surrounds the material to be heated, the apparatus comprising first and second sensors and which are conveyed through such an oven by the conveying means with the first and second sensors in line astern, wherein each sensor has a first surface and a second surface and comprises a layer of a thermally insulating material between said first and second surfaces and means for providing a signal representing a temperature difference across the layer, the first surface of each sensor being in contact with a heat sink and the second surface of each sensor being exposed, and each sensor including means for giving a signal representing the temperature of the exposed surface of the sensor, the first sensor is radiation-absorbing and the second sensor is reflecting, the exposed surfaces of the two sensors are substantially coplanar and the two sensors are spaced apart from one another, and which apparatus includes means for giving a signal representing the gas temperature in the vicinity of the exposed surfaces of the sensors, and which apparatus also comprises means for periodically recording data derived from the signals from each of the sensors and from the means for measuring the gas temperature in the vicinity of the two exposed surfaces, and wherein the recording means is arranged to correlate the signals from one of the sensors at one instant, with the corresponding signals relating to the other sensor at a later instant, the difference in time between the two instants being, or being adjustable to be, equal to the time taken, when in use the apparatus is being conveyed through the tunnel oven, for one sensor to reach a position formerly occupied by the other sensor.