This article depicts the role of the Digital Calibration Certificate (DCC) for an end-to-end digital quality infrastructure and as the basis for developments that are designated by the keyword “Industry 4.0”. Furthermore, it describes the impact the DCC has on increasing productivity in the manufacturing of products and in global trade. The DCC project is international in its scope. Calibration certificates document the measurement capability of a measurement system. They do this independently and by providing traceability to measurement standards. Therefore, they do not only play an important role in the world of metrology, but they also make it possible for manufacturing and commercial enterprises to exchange measurement values reliably and correctly at the national and at the international level. Thus, a DCC concept is urgently needed for the end-to-end digitalization of industry for the era of Industry 4.0 and for Medicine 4.0. A DCC brings about important advantages for issuers and for users. The DCC leads to the stringent, end-to-end, traceable and process-oriented organization of manufacturing and trading. Digitalization is thus a key factor in the field of calibration as it enables significant improvements in product and process quality. The reason for this is that the transmission of errors will be prevented, and consequently, costs will be saved as the time needed for distributing and disseminating the DCCs and the respective calibration objects will be reduced. Furthermore, it will no longer be necessary for the test equipment administration staff to update the data manually, which is a time-consuming, tedious and error-prone process.

During the past decade, piezo-resistive cantilever type silicon microprobes for high-speed roughness measurements inside high-aspect-ratio microstructures, like injection nozzles or critical gas nozzles have been developed. This article summarizes their metrological properties for fast roughness and shape measurements including noise, damping, tip form, tip wear, and probing forces and presents the first results on the measurement of mechanical surface parameters. Due to the small mass of the cantilever microprobes, roughness measurements at very high traverse speeds up to 15 mm/s are possible. At these high scanning speeds, considerable wear of the integrated silicon tips was observed in the past. In this paper, a new tip-testing artefact with rectangular grooves of different width was used to measure this wear and to measure the tip shape, which is needed for morphological filtering of the measured profiles and, thus, for accurate form measurements. To reduce tip wear, the integrated silicon tips were replaced by low-wear spherical diamond tips of a 2 µm radius. Currently, a compact microprobe device with an integrated feed-unit is being developed for high-speed roughness measurements on manufacturing machines. First measurements on sinusoidal artefacts were carried out successfully. Moreover, the first measurements of the elastic modulus of a polymer surface applying the contact resonance measurement principle are presented, which indicates the high potential of these microprobes for simultaneous high-speed roughness and mechanical parameter measurements.

The paper deals with cantilevers made from monocrystalline silicon by processes of microtechnology. The cantilevers are passive structures and have no transducers. The application as a material measure for the inspection of stylus forces is in the center of investigations. A simple method is the measurement of the deflection of the cantilever at the position of load by the force if the stiffness of the cantilever at this position is known. Measurements of force–deflection characteristics are described and discussed in context with the classical theory of elastic bending. The methods of determining the stiffness are discussed together with results. Finally, other methods based on tactile measurements along the cantilever are described and tested. The paper discusses comprehensively the properties of concrete silicon chips with cantilevers to underpin its applicability in industrial metrology. The progress consists of the estimation of the accuracy of the proposed method of stylus force measurement and the extraction of information from a tactile measured profile along the silicon cantilever. Furthermore, improvements are proposed for approaches to an ideal cantilever.

Zusammenfassung: Der Prototyp eines maschinenlesbaren und maschineninterpretierbaren Digitalen Kalibrierscheins (DCC, engl. Digital Calibration Certificate) wurde bereits im Jahr 2017 in den PTB-Mitteilungen [S. Hackel, F. Härtig, J. Hornig, und T. Wiedenhöfer, The Digital Calibration Certificate, PTB-Mitteilungen, vol. 127, Bd. 4, S. 7, 2017 [Online]. Verfügbar unter: https://oar.ptb.de/resources/show/10.7795/310.20170403 [Zugegriffen: Jul. 2, 2019].] veröffentlicht. Die Idee basiert auf dem im Jahr 2016 von der PTB skizzierten europäischen Forschungsvorhaben SmartCom (17IND02) [,,Welcome to SmartCom”, 2021 [Online]. Verfügbar unter: https://www.ptb.de/empir2018/smartcom/project/ [Zugegriffen: Februar. 15, 2023]; EURAMET-European Association of National Metrology Institutes, ,,Communication and validation of smart data in IoT-networks”, EURAMET, 2023 [Online]. Verfügbar unter: https://www.euramet.org/research-innovation/search-research-projects/details/project/communication-and-validation-of-smart-data-in-iot- networks [Zugegriffen: Februar. 15, 2023.] und ist seit dem Jahr 2017 integraler Bestandteil des Digitalisierungskonzepts der PTB. Der DCC bietet die weltweit eindeutige Identifikation und Speicherung der Eigenschaften eines beliebigen Kalibriergegenstandes und leistet damit mehr als den reinen Nachweis der metrologischen Rückführung. Der von der PTB prototypisch entwickelte DCC beruht auf dem Austauschformat XML und ist damit sowohl zukunftssicher maschinenlesbar als auch maschineninterpretierbar. Darüber hinaus sind alle Anforderungen der DIN ISO 17025 [DIN EN ISO/IEC 17025:2018-03, Allgemeine Anforderungen an die Kompetenz von Prüf- und Kalibrierlaboratorien (ISO/IEC_17025:2017); Deutsche und Englische Fassung EN_ISO/IEC_17025:2017, Beuth Verlag GmbH [Online]. Verfügbar unter: https://www.beuth.de/de/-/-/278030106 [Zugegriffen: Sept. 24, 2021].] berücksichtigt. Für die Darstellung von Messwerten wurde im Projekt SmartCom ein auf den SI-Einheiten basiertes Datenmodell entworfen und ein prototypisches XML-Datenaustauschformat entwickelt. Dieses als D-SI (digitales SI [D. Hutzschenreuter u.a., SmartCom Digital-SI (D-SI) XML Exchange Format for Metrological Data Version 2.0.0, 2021 [Online]. Verfügbar unter: https://zenodo.org/record/4709001 [Zugegriffen: Mär. 10, 2022].]) bezeichnete Format bildet unter anderem die Grundlage für die Angabe von Messdaten im DCC. Darüber hinaus ist es nutzbar für jeglichen anderen Austausch metrologischer Informationen. Alle Angaben einschließlich numerischer Kalibrierkurven können aus dem DCC heraus direkt und automatisiert in digitale Prozesse übernommen werden. Kryptografische Signaturen als Sicherungsverfahren sorgen für die Integrität und Authentizität eines DCC. Alle Konzepte wurden mit Partnern in Europa und der Welt diskutiert, abgestimmt und werden weiterentwickelt.

A tactile probe sensor was addressed which was designed for quality assurance of high-aspect ratio micro parts, e.g. engineered apertures of fuel nozzles. It was constructed as an extremely slender silicon cantilever of 1-5 mm in length, 30-200 mum in width and 25-50 mum in height comprising a pyramid-shape probing tip and a piezoresistive strain gauge for signal read out. The tactile sensor can be operated at scanning speeds several orders of magnitude higher than conventional atomic force microscopes offering mm scanning range at mum lateral resolution. The 5-mm-long cantilever can be deflected vertically by 200 mum exhibiting a non-linearity of 0.3 %FS and nanometer resolution at high sampling rates in the kHz range. Cross sensitivity vs. temperature and ambient light referred to deflection is below 10 nm at typical measurement conditions of temperature and light intensity variations of 1 K and 0.1 mW/cm², respectively.