Is the air clean?

How do you measure germs? You let a stream of air flow towards a petri dish containing a suitable culture medium for bacteria or fungi and, after an incubation period of several days, check whether colonies of the collected microbes have grown in the petri dish. But the devil is in the detail: How can you ensure that all germs end up in a defined volume of air in the petri dish? Especially as this air contains only the smallest amounts of impurities?

An ingenious system of air channels ensures that all germs end up in a defined volume of air in the Petri dish – especially as this air contains only the smallest amounts of impurities. The accelerated air is forced into an extreme change of direction just before it reaches the surface of the culture medium. As the heavy particles in the air stream cannot follow this change of direction, they are deposited on the Petri dish with great reliability. The parameters relevant to the accuracy of this process, such as flow rate, pressure, temperature and humidity, can be measured continuously using integrated sensors.

Swiss precision

Not purely for regulatory reasons, but in particular because intensive quality control is essential for the manufacture of products such as pharmaceuticals and medical devices and contamination can have potentially life-threatening consequences, the device must fulfil the highest requirements in terms of accuracy and reliability – for every single measurement.

Reliable and traceable

Precision in determining the collection volume of air is not the only factor that influences the measurement result. Incorrect use of device components, human error during use and inaccurate calibration processes can cast doubt on the measurement result. Therefore, during development, great importance was attached to recognising as many sources of error as possible through intelligent test procedures during the measurement and warning the user. In highly regulated environments such as the pharmaceutical industry, it is also essential that the device stores data on all relevant processes in an unalterable form so that it is possible to trace what was done by which user and when. This is the only way to correctly identify weak points in procedures and handling as well as the resulting risks.

Architecture of the air sampler

SCS developed the software for the latest generation of portable air samplers for MBV AG, the world’s leading manufacturer of microbial air samplers based in Stäfa. The hardware consists of two units: The head with fan, sensors and an electronics board in the upper part and the base, the lower part, with a Linux board. The base sends commands to the head via a communication protocol and receives all relevant parameters for the system logs in return. The Linux board can communicate with external devices such as a PC, barcode reader or the calibration device via a USB interface or a Wi-Fi dongle.

User management

Intuitive user management ensures that each user only receives the rights that correspond to their role. All devices that are in the same network and the same user group are automatically synchronised with each other without the need for a central server. This is done using a specially designed protocol. In large pharmaceutical companies, the company’s own Microsoft Active Directory can be used so that users can log in with their usual access data.