An inexpensive optical sensor for monitoring total suspended particulates in air

The objectives of this paper are to design an inexpensive optical sensor and present the technique for measuring total suspended particulates (TSP) concentrations in air samples. The designed sensor was based on the transmitted properties of particles in air samples. It used LED's as sources and a phototransistor as detector. The detected signals were displayed in terms of the output voltage readings recorded by a voltmeter. The algorithm has been developed and used for the measurement of TSP concentrations. The linear correlation coefficient between the estimated TSP and measured TSP was high and the root mean square error was low.