ISO 25597

Description / Abstract: General

This International Standard specifies procedures for the extraction and measurement of filterable particulate matter from stationary source flue gas samples by:

— the use of cyclone samplers;

— the measurement of condensed particulate matter using dilution sampling technique, which simulates the interaction of stack gas components with the atmosphere as they mix after the stack exit.

This International Standard provides for the use of two types of sampling train.

— Basic sampling train, a basic sampling train to measure filterable particles using sampling cyclones that can distinguish between particle sizes in the range of 2,5 μm and 10 μm. This method is especially suitable for measurements of particle mass concentrations above 50 mg/m³ a s a halfhourly average at standard conditions (293 K, 1 013 hPa, dry gas) and applies to primary particulate matter (PM) emissions equal to or less than an aerodynamic diameter of nominally 10 μm (PM₁₀) from stacks or ducts.

— Dilution sampling train, a dilution sampling train that utilizes a dilution chamber that mixes flue gas with conditioned dilution air to simulate the interaction of the stack gas components with ambient air. This simulation process may lead to the condensation of particulate matter that might not otherwise be produced in the basic sampling train. The dilution sampling train uses in-stack sampling cyclones to measure filterable particles in the same manner as the basic sampling train, but in addition, utilizes additional PM_2,5 and/or PM₁₀ cyclones in the sampling train to measure particles formed in the dilution chamber.

This method is intended for the measurement of mass concentrations of particles smaller than 2,5 μm aerodynamic diameter (PM_2,5) using weighing techniques. The method can be used to measure mass concentrations of particles with aerodynamic diameter smaller than 10 μm aerodynamic diameter (PM₁₀) or particles with aerodynamic diameters between 2,5 μm and 10 μm.

In this method, the dilution sampling train can be used in combination with the basic sampling train, using PM₁₀ and/or PM_2,5 depending upon the test objectives. The dilution sampling system is intendedfor applications where measurement is required of particles similar in characteristics to materials formed when a flue gas exhaust mixes with ambient air.

Particulate matter filter samples collected using dilution sampling can be further analysed to provide chemical composition data that are applicable for developing PM_2,5 or PM₁₀ emission inventories, visibility impact assessments, health risk assessments, and source–receptor studies related to PM_2,5 and PM10 emissions.

This method is not applicable to the determination of ultrafine particles with an aerodynamic diameter of less than 0,1 μm. This method has been applied to emission sources with low moisture and saturated moisture stack gases; however, it is not applicable to effluents where entrained water droplets are presented.

NOTE Optionally, with additional equipment, as well as sampling and analytical procedures not described in the method, PM chemical speciation and particle size can be determined by applying ambient air sample collection and analysis methods to the diluted stack samples obtained by using this method. In addition, the concentration of gaseous precursors that can contribute to the formation of particulate matter, e.g. SO₂, NO_x, ammonia, SO₃, HCl, volatile organic comounds (VOCs), can be determined using suitable analytical equipment to measure the diluted samples.