Patent ID: 6659638
Filing Date: 2003-12-09
Classification: G01N

Abstract:
An accelerated weathering test apparatus of the type used to concentrate solar radiation upon test specimens, the apparatus dynamically controlling a test specimen temperature in order to simulate complex temperature cycles of a material end-use application, the apparatus comprising:a target board for supporting at least one test specimen to be exposed to concentrated solar radiation; a reflector device for reflecting solar radiation and concentrating the reflected solar radiation on to the target board for illuminating the at least one test specimen; an air circulation device for circulating ambient air over the target board for adjusting the temperature of the at least one test specimen, the air circulation device including an electric motor and a fan powered by the electric motor for creating a flow of ambient air; a feedback device mounted to the target board for exposure to the concentrated solar radiation and generating a test signal responsive to a temperature thereof and representative of the test specimen temperature; an input device which continuously generates a dynamic reference signal representative of a complex temperature cycle of a material end-use application; and a controller connected to the input device and responsive to the dynamic reference signal in order to generate a temperature set point, and the controller further connected to the feedback device and responsive to the test signal for selectively controlling the application of electrical power to the electric motor in order to control a rate at which ambient air is circulated over the target board, the rate being generally increased when the temperature of the feedback device is greater than the temperature set point, and the rate being generally decreased when the temperature of the feedback device is less than the temperature set point, and the rate being generally maintained constant when the temperature of feedback device is substantially equal to the temperature set point.