An experimental method for predicting the solar radiation intensity distribution incident on the absorber of a line-axis Compound Parabolic Concentrator (CPC) has been developed. A relationship has been derived that correlates insolation intensity with rate of temperature rise, based on first order time/temperature response curves obtained From thermocouples exposed to direct solar radiation. Employing this technique the energy flux distribution on the absorber of three line-axis CPC has been determined. The results have been validated with a 2-Dimensional raytrace analysis.