Microbial Air Samplers: Understanding Sample Rates

Microbial Air samplers are used in a variety of environments, in a wide array of industries, ranging from food production lines, surgical amphitheaters, to pharmaceutical cleanrooms. Each application and environment may require differing sampling parameters (e.g., sampling periods, sampling rates, etc.), and understanding the difference between various sample rates, and associated particulate capture velocities, can help you better determine which type of air sampling you need and which devices will give you the best possible results.

Capture Velocity
Capture velocity is a deciding factor in your sample rate. The combination of a device’s flow rate and its inlet size, in conjunction with the distance of the inlet to the media surface, result in specific capture velocities, and capabilities, of particulates and microbial organisms. Air sampling devices offer capture velocities as low as 5 meters per second to over 135 meters per second; the ideal range is around 25-80 MPS.

The Importance of Capture Velocity
A microbial air sampler’s capture velocity is more than just a line item on a devices specifications — it is a critical component of the device’s functionality that has a big impact on its overall effectiveness. If the velocity is too low, smaller organisms and spores will not be retained. If it is too high, the force of hitting the media could render microbes non-viable.

Sampling Rates

High sample rates are best for short sampling periods and low sampling rates are best for long sampling periods. But, it is important to assure whether you have a high or low sampling rate, that your capture velocity remains consistent, for a consistent and comparable data set of your environments.  Your required sampling periods will be dictated by the work you do and the environment in which you do it.

There is much to learn when it comes to microbial air samplers. Each individual device provides a specific list of features that may or may not be appropriate for your requirements. Knowledge in the basic specifications that set these devices apart helps you make the right decisions for your work environment, and ensures you do not compromise samples with an inappropriate sampling device.

For more information about the technical details of our samplers or the best sampler for your needs please visit www.emtekair.com.