The SM-4 Mercury Monitor is the industry's most advanced and cost effective solution to EPA compliance. The Cemtrex SM-4 has been designed to meet especially the requirements for measuring gases with very low Hg concentrations in a matrix of increased concentrations of SO2, NOx, HCl and others as found in stack gases. Applications include coal fired power plants, waste incinerators, cement kilns and all other process gases which contain mercury traces in a complex matrix.