SPM & RSPM measuring techniques

Instruments required to measure the SPM & RSPM (Respirable Particulate Matter) are as follows:-

1. SPM measuring Techniques/Instruments;-

- Beta-ray absorption method

- Piezoeletric Balance method

- Light scattering method

- Absorption method

High volume Sampler is generally used for measurement of the suspended particulate matter (SPM). High Volume Sampler contains a filter paper which is fitted in the sampler. The sampler is started and adjusted flow rate about 2 lit/min of air for 24 hrs. The flow rate is noted down at the end of the desired sampling period and sampler is stopped. The weight of the exposed filter with a standard balance is noted at end and further calculation is done for the concentration of SPM in air.

2. RSPM measuring Instrument:-

- Fine particulate Sampler (same as high volume sampler with impactors for PM10 & PM2.5).

- Dust track (automatic samplers) for PM10, PM2.5 & PM1.0.

In dust track automatic sampler, the following procedure is followed for measuring the concentration of RSPM:-

Clean the filter box of the dust track. Prepare the sampling assembly with the required inlet size. At one time only one size can be monitored. Check the flow rate with the help of accessory given with it. Set the time constant to 10 sec or larger depending upon required averaging period. Instrument can be switched on to survey mode for spot checking. Instruments will display concentration values in mg/m3. For continuous monitoring, it needs to be set in login mode. Having set the mode, place it in the environmental chamber and make connection with the batteries. Connect the outdoor probe, switch on the instrument and close the chamber the capacity of storing the data is about 32000 observations in every second.