Perforated Lid

The Perforated Lid with 400 x 0.7 mm hole sieve is used for microbial monitoring of ambient air with portable MAS-100 microbial air samplers. Especially MAS-100 Eco. Microbial air sampling devices are extensively used in Pharmaceutical and Personal care industries as well as Food, Beverage and Environmental applications. Additionally, a regulation for compounding pharmacies, USP797, that requires active air sampling in the level 5 and above areas.

The Perforated 400 x 0.7 mm hole lid is made from anodized aluminum and can be used with all portable MAS microbial air samplers, especially designed for the MAS-100 Eco. The sieve of the perforated lid is at the core of the 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 400 holes of a diameter of 0.7 mm provides an impaction speed of approximately 11 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 1.62 1μm (D50) while maintaining the viability of microorganisms during impaction on the agar surface. The aluminium perforated lid can be autoclaved and disinfected with all disinfectants compatible anodized aluminium 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.

Replaces: 1.09088.0002

MAS-100 is a registered trademark of MBV AG

MAS-100 Eco is a registered trademark of MBV AG