Reason: According to international standards (e.g. ISO 9000, GLP), test equipment must be calibrated at intervals by comparison with a standard or a calibrated testing apparatus.
This calibration also applies to the 20-l-apparatus and the 1-m3-vessel for the determination of Pmax and Kmax and the apparatus for determination of the minimum ignition energy. The test procedure is an important part of this calibration. A general check at the component level is incomplete and hence inadmissible.
Unfortunately there are neither internationally recognized reference samples nor reference equipment available for the determination of these explosion characteristics. Therefore, a calibration round robin test (CaRo) will be carried out every two years.

Calibration method: The mean values of the explosion indices, measured by the par­ticipating laboratories, will be calculated as reference values. All apparatus, with results lying within the given tolerance range, meet the calibration requirements and will receive a calibration-certificate from us.

Based on experience with previous round robin tests, we are certain that we will be able to discover and rectify the cause of any errors with installations producing results differing widely from the reference values.

Our service: The test dust will be selected, homogenized, packed under nitrogen and mailed by us. Additionally we supply with the test dust preliminary reference-results (20-l-apparatus and MIKE 3 minimum ignition energy apparatus). Therefore you will be able to pre-check your own test results. On elapse of the test deadline, a detailed overall evalua­tion with calculation of the standard values and the associated tolerance range will be made. Those laboratories which meet the calibration requirements will receive a certificate. All results will then be summarized in tabular form (anonymously) and mailed to the participants.