초록 ▼

Method for the certification of heater blankets by means of infrared thermography, in which a heater blanket (1) to be certified is enclosed in a vacuum bag (3,4,5,5',8,9,10) arranged above a support (2) and thermally insulated therefrom, the vacuum is formed inside said bag and said heater blanket

Method for the certification of heater blankets by means of infrared thermography, in which a heater blanket (1) to be certified is enclosed in a vacuum bag (3,4,5,5',8,9,10) arranged above a support (2) and thermally insulated therefrom, the vacuum is formed inside said bag and said heater blanket is connected until its temperature is stabilized at a predefined value, considerably higher than the ambient temperature, whereupon the best infrared image or images of said heater blanket (1) are recorded and stored by means of an infrared camera (14) situated opposite it, then interrupting the electric power supply to said heater blanket and processing the stored images so as to produce, finally, a certification report.

대표청구항 ▼

The invention claimed is: 1. Method for certification for a uniformity of temperature tolerance of a heater blanket by infrared thermography, comprising the steps of: a) preparing a heater blanket to be certified, confining said heater blanket within a vacuum bag arranged above a support made of th

The invention claimed is: 1. Method for certification for a uniformity of temperature tolerance of a heater blanket by infrared thermography, comprising the steps of: a) preparing a heater blanket to be certified, confining said heater blanket within a vacuum bag arranged above a support made of thermally insulating material, said heater blanket being arranged substantially horizontally with respect to said support; b) arranging a reference thermocouple in direct contact with said heater blanket; c) generating a vacuum inside said vacuum bag; d) arranging an IR camera opposite said heater blanket so that a geometrical axis of the lens of said camera forms an angle of, substantially, 90 degrees with a plane of said heater blanket; e) connecting a power supply to said heater blanket for a first heating time period until a temperature measured by said thermocouple on the surface of said heater blanket is higher than ambient temperature; f) keeping said power supply connected during a second time period for stabilization of the temperature; g) recording an IR image or a sequence of IR images of said heater blanket during operation by means of said IR camera; h) storing the image or the sequence of images recorded; i) interrupting the power supply to said heater blanket and allowing the heater blanket to cool; and j) processing the stored image or sequence of images to determine the uniformity of temperature tolerance of the heater blanket. 2. Method according to claim 1, wherein said IR camera has a narrow optical filter coupled to its lens. 3. Method according to claim 1, wherein said substantially horizontal support is a thermally insulating support. 4. Method according to claim 1, wherein said heater blanket support forms a maximum angle (Θbase) of 40° with the horizontal. 5. Method according to claim 1, wherein said step j) comprises the steps of: i) generating and storing a mean image of said sequence of images acquired during the operation h); ii) drawing a thermometric analysis grid on top of said mean image thus generated, said grid being divided into cell; iii) determining maximum temperature limit values and minimum temperature limit values of the cells of said grid so as to obtain a temperature difference between said maximum and minimum temperature limit values of the cells; and iv) comparing the temperature difference thus obtained with a previously defined threshold value, so as to accept or reject said heater blanket depending on whether said temperature difference is lower than or higher than said threshold value, respectively.