First round-robin test to determine the recovery rate of test particles according to VDA 19 Part 1

Construction of the standard used for the ring test "ParticleMaster".

The specification analysis provides the exact number and size distribution of the test particles according to normal usage.

Standard particles / Test particles made of aluminum.

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In October 2016, Marhan - Normpartikel launched the first round-robin test for determining the recovery rate of test particles according to VDA 19 Part 1. By participating, companies and testing laboratories conducting cleanliness investigations according to VDA 19 Part 1 receive proof of the recovery rate of test particles from an independent body. This can be especially helpful during accreditations or audits.

After registration, participants receive a usage standard with individual test particle loading, called the "ParticleMaster," without predefined analysis. It is a glass slide that is carefully contaminated with test particles. The test particles are fixed on the slide in such a way that they detach during a cleanliness investigation extraction process and are introduced into the process flow of the cleanliness test—extraction – drying – filter handling – microscopy. The number and size distribution of the standard particles on the slide are microscopically determined, and the result protocol, known as the predefined analysis, is attached to the contaminated slide. It is part of the standard and provides information about the exact particle count and size distribution of the test particles on the slide. This way, an object with a known contamination level is created.

Since the predefined analysis is initially not disclosed to the round-robin participants, they do not know the level of contamination of the slide at the time of application. Participants perform a cleanliness investigation according to VDA 19 on the usage standard and submit the result protocol to Marhan - Normpartikel. Marhan then calculates the recovery rates of the test particles for all participants and provides each with their own result, along with the corresponding predefined analysis. Additionally, all participants receive the calculated recovery rates of the other participants in anonymized form. This approach allows participating laboratories to compare their own results with those of others and to self-assess. Furthermore, determining the recovery rate of test particles offers valuable insights into the capabilities of all process steps involved in a cleanliness investigation, such as extraction, rinsing procedures, filter handling, and drying, as well as proof of the functionality of the entire testing equipment—from extraction devices to drying ovens and microscopes. Participation in the round-robin includes the usage standard "ParticleMaster," the calculation of the individual recovery rate of test particles, and the submission of overall results. Thus, Marhan - Normpartikel offers a highly informative alternative to conventional round-robin tests in the field of technical cleanliness, where participants are usually provided with objects of unknown contamination levels. Using the described standard, it is now possible to calculate the results of all participants, which in turn allows for an accurate percentage classification of one's own performance for the first time. However, the method does not aim to compete with round-robin tests that use original components for comparison measurements. Correct execution of extraction on non-standardized objects remains very important in practice.

Any independent or in-house laboratory conducting cleanliness investigations according to VDA 19 is eligible to participate. Marhan - Normpartikel commits, in connection with the round-robin, to never disclose results in connection with the name or any reference to the laboratory / company where the cleanliness investigation for the respective test result was performed to third parties. After successful participation, Marhan - Normpartikel provides all participants with a certificate showing their respective individual result as proof for customers or auditors.

Following the successful introduction of the first round-robin test for qualification according to VDA 19 Part 1, a continuous annual repetition of the test is planned. This provides participants with a periodic opportunity to monitor their process flows and the functionality of laboratory equipment. Additionally, participants are continuously informed about the quality of their own processes in comparison to other facilities, which may indicate a need for optimization. Since Marhan - Normpartikel, as a leading manufacturer of standard and test particles required for the test, produces the necessary usage standards itself, no complex coordination of corresponding components is required. This results in significantly higher statement power compared to previous round-robin tests, as well as a considerably lower participation fee. In-house laboratories are recommended to conduct cyclical monitoring of process capability and laboratory equipment, as well as documenting these results in accordance with DIN EN ISO 9001. Accredited laboratories are required to participate regularly in round-robin tests as part of official approval procedures. DIN EN ISO / IEC 17025 mandates annual participation, allowing the quality of test laboratory results to be proven and their competence demonstrated. Many laboratories, including in-house laboratories of renowned international automotive manufacturers and their suppliers, have already registered for the round-robin. Registration for this year is still possible until the deadline on October 31, 2016. The higher the number of participants, the closer the goal, also promoted by this measure, to increase the comparability of cleanliness investigation results.