Like all good ideas, it is based on a rather simple concept. Sartorius realised that conventional detectors that operate on the basis of electromagnetic alternating fields are limited when they encounter packaging, or parts of packaging, made of aluminium. And tests using X-rays are expensive, and require elaborate safety measures to ensure protection against radiation.
But for the Observer, the composite packaging of items such as blister packages around tablets presents no problem. Because aluminium does not have any magnetic properties, it appears transparent to the metal detector.
Sartorius also claims that the Observer is impervious to interference by metal parts in the surrounding environment. This is possible thanks to the metal detector's specific calculating operations that eliminate noise or stray fields in the signals received by the built-in sensors.
This sensor technology and specific evaluation electronics has been jointly developed by Sartorius and German firm STL. Besides testing aluminium packaged products in the pharmaceutical and food industries, further applications for the Observer metal detector include detection of product flow in stainless steel pipes.
Sartorius says that the Observer will be unveiled at the Total 2004 event, to be held in Birmingham, UK's NEC in March.