Measurement system for solar radiation

Abstract

We present in this paper the principles of the measurement system for solar radiation. The photocurrent produced by a silicon PN junction is used as a solar radiation transducer. Using a silicon solar cell as sensor, a low cost solar radiometer can be constructed. The photocurrent produced is electronically tailored to store solar radiation data in a microprocessor based data acquisition system. This portable instrument can be used in remote sites and substitutes solar monitor and integrator. The data can be transmitted by a RS 232C port, interfaceable with personal microcomputer. We developed a system hardware and software, based on MC 68B09 microprocessor, able to work in remote sites or linked to a laboratory. So, the global irradiation data are obtained after correction using the instantaneous measure of the ambient temperature which allows us to calculate the junction temperature and consequently improve the precision of measure of this measurement system.