Process photometer operation comprises determining condition of filtered and unfiltered gas at given time intervals

摘要

In a process to operate a process photometer, a sample gas flow passes through a cell. Prior to its admission to the cell, the sample gas passes through an absorptive or adsorptive filter in which there is chemical or physical separation of selected gas components and unwanted gas components. The filtration process result is incorporated in the evaluation of the signal measured. An Independent claim is also included for an assembly in which hydrogen sulfide gas is removed by a granulated lead carbonate filter cartridge. Preferred Features: The filter is a selective absorptive or adsorptive filter which selectively removes the unwanted gas components. The photometer measures the sample in both the filtered and unfiltered conditions at pre-determined intervals, registering both results and determining the difference.