Perforated Lid

The Perforated lid for MAS-100 NT^® (400 x 0.7 mm) is made from anodized aluminum and can be used with the portable the MAS-100 NT^® series, MAS-100 VF^® and MAS-100 Eco^® microbial air samplers. This version is provided with edge protection in order to protect the dealing surface from scratches and damages. 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 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 1.6 μm (d50, calculated) while maintaining the viability of microorganisms during impaction on the agar surface (biological efficiency). The perforated lid can be autoclaved and disinfected with all disinfectants compatible anodized aluminum in order to avoid false positive results in high grade cleanrooms. 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. This verion might be used, in case historical data with 400x0.7 mm sieve heads are available for comparison. Nevertheless for optimized collection efficiency of the MAS-100^® portable air sampler range, we recommend to use perforated lids with 300x0.6mm sieves, except for MAS-100 Eco^®.

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 in controlled environments. Microbial air sampling devices are extensively used in Pharmaceutical and Personal care industries as well as in Food, Beverage and Environmental applications.

MAS-100 is a registered trademark of MBV AG

MAS-100 Eco is a registered trademark of MBV AG

MAS-100 NT is a registered trademark of MBV AG

MAS-100 VF is a registered trademark of MBV AG