ImpactAir-140 - 14cm Plate Monitoring

ImpactAir® high performance slit-to-agar microbial air sampler

ImpactAir-140 is designed for continuous monitoring in high-grade areas, where in-process sampling of viable particles is often critical.

Air is drawn at high speed through a very narrow inlet slit, whereupon particles, including microbes in the air, impact and stick onto an agar surface in a Petri dish.

The Petri dish is slowly rotated under the inlet thus ensuring the air is always ‘impacted’ onto a fresh area of agar. This dramatically reduces the probability of ‘twin impingement‘, a phenomena where two microbes land at the same point and appear as a single colony when incubated – this is an issue associated with sieve type samplers.

The ImpactAir® range uses the larger 14 cm Petri dishes which allow the system to sample for longer periods onto a single dish. The sampling time is programmable from minutes to many hours. With a deep fill agar plate it is possible to sample for several hours onto a single agar plate. Sampling 1 m3 is achieved in 35 minutes and 20 seconds with the flow rate of 1 cubic foot per minute.

With any impaction sampler, the distance between the inlet and the surface of the agar is critical and has a major effect on the sampling efficiency. The agar in petri dishes is often not at a constant depth so the ImpactAir®is the first sampler of its kind to employ precision sensing and control to automatically adjust the distance throughout an entire run to ensure a consistent d50 value is maintained. This is supported by the results obtained from the independent physical and biological validation carried out by Public Health England (PHE). Full reports are available.

Unlike some other air samplers, ImpactAir® due to its unique design does not shed particles so is able to operate in environments alongside particle counting devices without causing increased readings. ImpactAir® exhibits very low vibration and can therefore be operated near balances.