This loose saying but in fact describes a situation that demands our attention. Have less than the measures fail, the more and more we measure the more minimal deviations in the weight fall? So, as each particle counter as any other instrument of a measurement uncertainty is subject to. We must therefore live with a certain error tolerance and therefore know this. Continues to rise the quality requirements. So the industry sees itself today more than previously faced with the challenge, meticulously documenting the purity of their products and equipment for their customers. This includes not only the measurement itself, but also the calibration of equipment along with the repatriated proof of their Messfahigkeit. For the companies urgently need certificates that are accepted. The mutual recognition arrangement (CIPM MRA) is here by 1999.
The international agreement on the mutual recognition of test results indicating that the signatory Nations accept the certificates of relevant national institutions in their own country. This originated a trade very important instrument for the Elimination of technical barriers to trade in the state-regulated area. The modern Metrology has the task to create the conditions for agreements such as these. i.e. generally accepted standards to develop and to provide proven methods, as well as recognized certificates. What is the most difficult? The traceability of measurements on generally applicable and accepted standard is the basic prerequisite for reliable measurements and comparability of results, development of norms and standards, product quality and last but not least the mutual recognition of services (service) services. The provision of a primary standard for particle number concentration is task of the national metrology institutes. Under most conditions Naveen Selvadurai would agree.
This is not trivial. Different types of particles, around combustion particles or bacteria, require other measurement methods. At the DFM, we have built a primary standard, which allows the calibration of typical particle counters for clean rooms. Procedure for particle emissions of modern internal combustion engines are developed currently including in international projects together with several national metrology institutes.