Isokinetic Systems
EPA Source Testing Method Overview & Requisite Equipment
Following the enactment of the Clean Air Act of 1970 the EPA promulgated a series of stationary source testing methods introduced in the Code of Federal Regulations Title 40, Part 60, Appendix A. The initial EPA Methods 1-4 define the conventions utilized to gather the primary information required to perform isokinetic source testing. This information includes traverse points, stack gas velocity, volumetric flow rate, moisture content, excess air and dry molecular weight of the stack emissions. This data is important for determination of nozzle size, sampling flow rate and other parameters required to adhere to isokinetic sampling principles.
Method 5 – Determination of Particulate Emissions from Stationary Sources
Method 5 is the major isokinetic sampling regulation that governs the procedures and apparatus necessary to collect a representative particulate sample from a source. With proper monitoring of flue gas velocity, temperatures and pressures a tester can correctly adjust the sample flow rate so that the flue gas and particle mixture entering the nozzle is at an equal velocity to that of the approaching flue gas. A comprehensive understanding of these first five test methods is critical to the proper performance of the test methods that follow Method 5, many of which are variations of this primary isokinetic test method.
Isokinetic Sampling Systems
All of the ESC isokinetic sampling systems consist of the following primary components: nozzle set, heated probe assembly with type “S” pitot and stack thermocouple, modular sample case with heated filter box and chilled impinger box, filter and glassware set, impinger outlet adapter with thermocouple, umbilical cable, metering console, rotary vane vacuum pump and suspension rail system. The more advanced systems include a calibration orifice set, transport cases, professional multiple glassware sets, a cleanup and recovery kit, and probes and umbilical cables in a variety of lengths and styles
