US EPA Method 4

Method 4

Determination of Moisture Content in Stack Gas

This method is applicable for any stack or source that contains moisture. The method contains two possible procedures: a reference method and an approximation method. The reference method is used for accurate determinations of moisture content (such as are needed to calculate emission data). The approximation method provides estimates of percent moisture to aid in setting isokinetic sampling rates prior to a pollutant emission measurement run.