ASTM D1331-14 pdf free download.Standard Test Method for Determination of Mass Concentration of Particulate Matter from Stationary Sources at Low Concentrations.

1.1 This test method2 covers a method for the measurement of particulate matter (dust) concentration in emission gases in the concentrations below 20 mg/m3 standard conditions, with special emphasis around 5 mg/m3.

1.2 To meet the requirements of this test method, the particulate sample is weighed to a specified level of accuracy. At low dust concentrations, this is achieved by:

1.2.1 Exercising extreme care in weighing,

1.2.2 Extending the sampling time at conventional sampling rates, or

1.2.3 Sampling at higher rates at conventional sampling times (high-volume sampling).

1.3 This test method differs from Test Method D3685/D3685M by requiring the mass measurement of filter blanks, specifying weighing procedures, and requiring monitoring of the flue gas flow variability over the testing period. It requires that the particulate matter collected on the sample filter have a mass at least five times a positive mass difference on the filter blank. High volume sampling techniques or an extension of the sampling time may be employed to satisfy this requirement.

1.4 This test method may be used for calibration of automated monitoring systems (AMS). If the emission gas contains unstable, reactive, or semi-volatile substances, the measurement will depend on the filtration temperature, and in-stack methods may be more applicable than out-stack methods for the calibration of automated monitoring systems.
2. Referenced Documents
Dl193 Specification for Reagent Water
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D2986 Practice for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phihalate) Smoke Test (Withdrawn 2OO4)
D3154 Test Method for Average Velocity in a Duct (Pitot Tube Method)
D3631 Test Methods for Measuring Surface Atmospheric Pressure
D3670 Guide for Determination of Precision and Bias of Methods of Committee D22
D3685/D3685M Test Methods for Sampling and Determination of Particulate Matter in Stack Gases
D3796 Practice for Calibration of Type S Pitot Tubes
El Specification for ASTM Liquid-in-Glass Thermometers
E225 1 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids.
4. Sunirnary of Test Method
4.1 A sample stream of the gas is extracted for a measured period of time at a controlled flow rate, and the volume of gas collected is subsequently measured. The particulate matter (dust) entrained in the gas sample is separated by a preweighed filter, which is then dried and reweighed. Deposits upstream of the filter in the sampling equipment are also recovered and weighed. The increase of mass of the filter and the deposited mass upstream of the filter plus (he deposits collected upstream of the filter are attributed to particulate matter collected from the sampled gas. The ratio of the mass of the particulate matter collected to the volume of gas collected allows for the calculation of the flue gas particulate concentration.
4.2 Valid measurements can be achieved only when:
4.2.1 The gas stream in the duct at the sampling plane has a sufficiently steady and identified velocity, a sufficient temperature and pressure. and a sufficiently homogeneous composition;
4.2.2 The flow of the gas is parallel to the centerline of the duct across the whole sampling plane;