Perforated Lid

The Perforated 300 x 0.6 mm hole lid is made from stainless steel and can be used with MAS-100 Iso NT^® and MAS-100 Iso MH^® microbial air samplers. The sieve of the perforated lid is at the core of the viable air sampler. Each hole must have an identical diameter and length to accelerate the aspirated air correctly. The 3mm thickness of the perforated sieve guarantee a well-defined impaction jet. The impaction speed defines the physical sampling efficiency. The cut-off value D50 (the particle size at which 50% of the particles impact in the agar due to inertia and 50% are exhausted with the airstream) must be identical between holes and between lids. That is why intense quality control of the sieves is performed. The sieve pattern with 300 holes of a diameter of 0.6 mm provides an impaction speed of approximately 20 m/s at a flow rate of 100 l/min. This impaction speed allows a high physical efficiency, meaning a sampling efficiency of more the 50% of small particles at a size of less than 1 μm (D50) while maintaining the viability of microorganisms during impaction on the agar surface (biological efficiency). The validation of physical and biological efficiency has been independently performed for each individual MAS Air sampler model. The edge protection prevents scratching of the sealing surface which would lead to aspirating air through the gap. The stainless-steel perforated lid can be autoclaved and disinfected with all disinfectants compatible stainless steel in order to avoid false positive results in high grade cleanrooms. This permit using a new lid for each sampling position or production batch or using lids while others are in the sterilization process and inaccessible. The sampling efficiency for an instrument must remain identical, irrespective of the lid used. Our perforated lids allow the exchange of several lids with identical sieve pattern on the MAS air sampler without the need of re-calibration.

MAS-100 is a registered trademark of MBV AG

MAS-100 ISO is a registered trademark of MBV AG

MAS-100 ISO MH is a registered trademark of MBV AG

MAS-100 ISO NT is a registered trademark of MBV AG