1.1 This standard prescribes the method for determination of particulate matter in a moving gas stream in confined space such as ducts, chimneys and flues for qualitative and quantitative measurements.
1.1.1 The procedure described is a method of sampling in stacks and flues, which has been standardized with the limits of variety of condi-tions encountered in the normal course of sampling stacks. Since any procedure or set of apparatus, which will satisfy a number of commonly encountered conditions, may often leave many other problems unanswered, the objective has been to select apparatus that gives reliable data when applied to a variety of situations. The apparatus selected permits a change
in the collecting element under stated conditions. The collector re-commended for use under specific field conditions and its use to obtain satisfactory results are. described. These procedures utilize particulate filtering systems which are located within the stack. If properly used, those systems are satisfactory for determining the mass concentration of particulate matter in the gas stream at stack conditions. The use of collection systems located outside the stack for collecting samples at other than in-stack conditions is an alternative.