Measurement of insolation using CdS photoresistor

Abstract

Using cadmium sulphide (CdS) photoresistor, the intensity of solar electromagnetic radiation (insolation) was estimated daily and hourly at Nsukka Campus of the University of Nigeria (latitude 6.8° North and longitude 7.35° East) for a period (October to January) of more than 3 months 1978/79. The mean daily insolation for the period was found to be 17.4 million J/m²/day. A modification of Rapp and Hoffman's empirical equation for local insolation was also obtained. The influence of rain and harmattan was observed.