Thermal issues of solar irradiation sensor

Nowadays the importance of solar cells and R&D in this field is steadily increasing. The most important parameter of a solar cell is the generated power, which can be enhanced by use of solar tracking. For a correct determination of the tracking system's efficiency an irradiation sensor is necessary, because the irradiation from the sun changes constantly. This sensor device is placed on the tracker's frame and transfers the intensity data to a monitoring system. The sensor developed for irradiation measurement must have accuracy and a reliable construction under outdoor use conditions (between the temperature values of -20degC and 80degC). The sensor is based on a photoelectric cell, and incorporates a read out circuit for providing steady short circuit conditions for the cell as well as for signal amplification. Thermal tests (HTS, LTOL) were accomplished in a climate chamber in the temperature range of -20 to 80degC in steps of 10degC. To determine the fundamentals of the thermal dependence of the sensor cell spectral response measurements under varying temperatures were performed.