Determining Airborne Contaminants with Personal Air Sampling Pumps
Used to evaluate a range of hazards such as dust, vapours and gases, personal air sampling pumps are commonly used by occupational hygienists to draw air at a known flow rate through a filter medium to determine airborne contaminants that are present in an environment. The amount of contaminant is measured and expressed as a concentration.
An air sample requires three basic measurements:
The flow of air through the collection medium
The sample runtime
The amount of contaminant collected.
How to Select and Use the Right Personal Air Sampling Pump with the Correct Sample Media
There are many different methods of collecting air samples, however, the most common is to use a battery-operated pump to draw a volume of air through a collection device (sampler) which is mounted in the breathing zone of the worker. A pump calibrator such as the Chek-Mate Air Sampling Pump Calibrator should be used before and after the air sample is collected to verify how much air is being pulled. As air passes through the sampler, any contaminants present in the air is captured on the medium (normally a filter paper for solid contaminants and sorbent for gases). The sample requirement is a prominent factor in determining the type of air sampling pump required. Dust sampling applications require a pump with high flow rates (up to 5000ml/min) whereas most gas samples will require a low flow rate between 20 and 500ml per minute.
Particulate Air Sampling
To sample particles such as fumes dust, mist and smoke, filter cassettes such as the SKC Cassettes are the typical sample media. The cassette is prepared and loaded to a convenient holder such as the SKC Cassette/Cyclone Holders which secures the cassette and the holder can then be clipped to a worker’s breathing zone. The connecting tubing of the cassette holder can be then attached to a calibrated air sampling pump and set to the recommended flow rate.
Gas and Vapour Air Sampling
Sorbent tubes are widely accepted as the preferred media for sampling gases and vapours. The glass sorbent tubes are prepared and inserted into a holder before being clipped onto an area near the worker's breathing zone. The sample media is connected to a calibrated air sample pump with tubing to complete the sample train.The sample which is trapped by the sorbent tube is then sent to a laboratory for analysis to determine the concentration of the contaminant.
The Sampling Guide available in the SKC Catalogue and the SKC website is a helpful resource in ensuring you have the correct sampling requirements for a particular hazard. The detailed SKC Sampling Guide covers both the HSE Method and NIOSH/OSHA/EPA/ASTM methods for sampling, providing important sampling parameters such as the flow rates, time, air volume and analytical method and most importantly the correct sampling media to use for collecting the chemical hazard to be sampled.
* To use for gas/vapour sampling at flow rates in the range 5 to 500 ml/min these pumps require a CPC (Constant Pressure Controller) or All-in-One adjustable low flow adapter.
We know selecting the right personal air sampling pump for the right application can be daunting. Speak to your local Air-Met Scientific representative to learn more about the Air-Met Scientific range of personal air sampling pumps. SKC air sample pumps are available at Air-Met Scientific for sale and rental. We also offer NATA accredited calibration and testing of air sampling pumps and flow meters.
