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The tilted-wave interferometer is an interferometrical measurement system for the accurate optical form measurement of optical aspheres and freeform surfaces. Its evaluation procedure comprises a high-dimensional inverse problem to reconstruct the form of the surface under test from measured data. Recent work has used a deep learning hybrid approach to solve the inverse problem successfully in a...

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The intense discussions on noise disturbance, particularly in the vicinity of wind turbines, raise the public awareness to infrasound (sound with frequencies < 20 Hz). Of major importance, thereby, is the knowledge about infrasound perception under realistic conditions, e.g. with binaural hearing. The monaural and binaural loudness perception of infrasound was investigated in a study with...

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Das Phasenrauschen hochfrequenter Signale wird in der Regel durch einen Vergleich des zu untersuchenden Signals mit einem rauscharmen Referenzsignal gleicher Frequenz gemessen. Bei kommerziellen Phasenrauschmessplätzen wird dieses Referenzsignal durch einen über einen weiten Frequenzbereich abstimmbaren Oszillator erzeugt. Dadurch wird die Messung zum einen durch den Frequenzbereich des...

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Aufbauschema Phantomleistungsmesssystem für Frequenzen bis 150 kHz

Die elektrische Leistungs- und Energiemessung bei Frequenzen oberhalb von 50 Hz gewinnt durch veränderte und neue Technologien zunehmend an Bedeutung. Beispiele sind hochfrequent taktende Umrichtersysteme zur Steuerung der Einspeisung regenerativer Energien ins Verbrauchernetz oder die Verbrauchsmessung an induktiven Ladesystemen für Elektrofahrzeuge, welche Leistungsmessungen im Frequenzbereich...

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The EMPIR Project “Supporting smart specialisation and stakeholder linkage in Photometry and Radiometry (Smart PhoRa)” has started on September 1st, 2021, for an 18-month funding period.

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The gravitational wave (GW) observatories calibrate interferometer displacement using photon momentum, with laser power serving as the measurand. These observatories are traceable to the International System of Units through a primary standard maintained by the US’s National Metrology Institute (NMI), the National Institute of Standards and Technology (NIST). The bilateral degree of...

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Logo des EMPIR-Projekts „TEMMT“.

Im Rahmen des Joint Research Project „Traceability for electrical measurements at millimetre-wave and terahertz frequencies for communications and electronics technologies“ (EMPIR 18SIB09 TEMMT) wurde durch die PTB am 21. Juli 2021 ein Online-Workshop als Trainingsveranstaltung für Experten aus der Hochfrequenzmesstechnik durchgeführt. Die Veranstaltung verzeichnete mit 95 internationalen...

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Through a collaboration between the PTB (Department 6.3), IRSN, NCBJ and EURADOS, new important interaction cross‑section data are being implemented in the Monte Carlo Geant4‑DNA simulation toolkit. This development should not only improve the accuracy of radiation transport simulations in tissue‑equivalent media, but also increase the versatility of using Geant4‑DNA in micro- and nanodosimetry.

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The International Commission on Radiation Units and Measurements (ICRU) has recommended new quantities for radiation protection in its Report No. 95. Values were calculated for these quantities to be able to estimate the consequences for the calibrations or irradiations of radiation protection dosemeters in the newly recommended radiation protection quantities with photon and/or beta radiation.

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Like everywhere else, time does not stand still for water meters. The requirements change, be it due to technological progress or changes in drinking water consumption. The question is whether measurement accuracy is still given under the changed conditions. Metrological infrastructure and procedures to address this question were discussed at a workshop organized by the EMPIR-project MetroWaMet.

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Elena Kononogova, PhD student in the working group 7.32 Infrared Radiation Thermometry has won the prize for the best poster at the “Symposium on Thermophysical Properties” in Boulder, which takes place every 3 years, with her poster "Development, Simulation...

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We apply an InGaAs quantum dot based single-photon source for the absolute detection efficiency calibration of a silicon single-photon avalanche diode operating in Geiger mode. The single-photon source delivers up to (2.55 ± 0.02) × 106 photons per second inside a multimode fiber at the wavelength of 929.8 nm for above-band pulsed excitation with a repetition rate of 80 MHz. The purity of the...

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Deckblatt des VDI-Statusreports „Terahertzsysteme und Anwendungsfelder“

Als Teil ihrer umfangreichen Normungs- und Standardisierungsaktivitäten arbeitet die PTB im VDI/VDE-Fachausschuss 8.17 „Terahertzsysteme“ mit. Das Ziel der gemeinsamen Normungsarbeit unter Beteiligung der PTB ist die Erstellung einer technischen Richtlinie, die ein gemeinsames Verständnis der Kenngrößen von Terahertzsystemen ermöglichen soll. Die PTB bringt abteilungsübergreifend ihre umfangreiche...

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During manufacturing of precision silicon spheres, their geometry must be controlled every day. A novel setup has been designed with a compact measurement loop, optical sensors and a handling strategy which avoids collision and contact with the very valuable, superpolished spheres. The design reduces the measurement time at each equator with sub-nanometre resolution to three minutes. 

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