OPAC 20/20-C OPACITY MONITOR COMBINER The OPAC 20/20-C opacity combiner takes the inputs from two to four OPAC 20/20 opacity monitors and combines the readings to obtain a stack exit correlated, opacity reading. The combiner is useful when total stack exit emission opacity must be known and the measurements are taken on more than one duct or breaching that feed a common stack. The combiner also excepts flow inputs for more accurate combiner readings.   © Phoenix instruments Inc. 1999 Contact Web Master