Stack Sampling | objective of Stack Sampling | Procedure of Stack Sampling

Stack Sampling

Stack Sampling or source sampling may be defined as a method of collecting representative samples of pollutant present in gas stream at the place of origin of pollutants to determine the amount pollutants emitted into the atmosphere from a given source in a given time.

Objectives of Stack Sampling

1. To determine quantity and quality of air pollutant emitted by the source.

2. To measure the efficiency of the control equipment by conducting a survey before and after installation.

3. To determine the effect on emission due to changes in raw material and processes.

4. To compare the efficiency of different controlling equipments.

5. To acquire data from various individual sources so as to determine the cumulative effect of many such sources.

Procedure of Stack Sampling

1. Mark the traverse point on the probe.

2. Determine the temperature and velocity at each traverse point.

3. Determine the flow rate to be sample.

4. Determine the empty weight of thimble (W1)

5. Insert the probe at traverse point 1, close to stack

6. Start the pump and adjust the flow rate at predetermined valve

7. Switch off the pump at the end of sampling time.

8. Note down the reading of volume of gas sampled from DGM.

9. Move the probe to the subsequent traverse point and repeat the step 5 to 8

10. Remove the thimble carefully. Weight the thimble with the sample (W2)

11. Determine the SPM by using following formula.