Die Mikrowellensynthese ist ein essentieller Bestandteil der Fontänenuhren. Mit ihr werden die für die Zustandspräparation und die Anregung des Uhrenübergangs benötigten Mikrowellensignale erzeugt. Unsicherheiten in diesem Teilsystem wirken sich direkt auf die Gesamtunsicherheit der Fontänenuhren aus. Durch Anpassungen im Synthesizer-Design wurden die Unsicherheitsbeiträge der Mikrowellensynthese...

On October 22 and 23, 2019, the 313^th PTB Seminar "VUV and EUV Metrology" took place in PTB's Hermann-von-Helmholtz building. At this workshop, by now the fifth arranged in a regular bi-annual cycle, 107 participants from research and metrology institutes as well as from industry discussed the newest developments and results in the field of applying radiation in the extreme- and vacuum-ultraviolet...

Single‐photon sources (SPSs) based on quantum emitters hold promise in quantum radiometry as metrology standard for photon fluxes at the low light level. Ideally this requires control over the photon flux in a wide dynamic range, sub‐Poissonian photon statistics, and narrow‐band emission spectrum. In this work, a monochromatic SPS based on an organic dye molecule is presented, whose photon flux is...

Die PTB und die Magnicon GmbH verbindet eine langjährige Partnerschaft bei der Entwicklung von Elektroniken zur Auslesung von SQUID-Sensoren für metrologische und wissenschaftliche Anwendungen. Im Rahmen eines ProFIT-Vorhabens zur Förderung industrieller Forschung in KMUs haben beide Partner in Zusammenarbeit mit dem Institut für ...

In cooperation with the Helmholtz-Center, Berlin, and the Tsinghua University, Beijing, a so-called proof of principle experiment towards Steady State Micro Bunching (SSMB) was successfully performed at the Metrology Light Source (MLS), the electron storage ring of PTB in Berlin-Adlershof. It could be proven that approximately one µm long structures created within a stored electron bunch of a few...

Spectral responsivity (SR) measurements are a powerful technique to measure the opto-electronic properties of photovoltaic devices like solar cells or PV modules. Although the SR determination of solar cells is a common and established technique for many years, much more effort must be taken to determine the SR of PV modules due to their size. Significantly larger and more complex solar simulator...

Solar simulators for PV modules often consist of several lamps arranged side by side to provide the irradiance necessary for PV module testing under standard test conditions. Since these simulators are no point sources, the angular distribution of the radiance emitted by the simulators can lead to systematic deviations in measured PV device’s performances. To quantify the opening angle of a solar...

Carbon oxides belong to the important anthropogenic and natural climate relevant compounds. WG 3.42 continued the work with carbon monoxide and dioxide, in cooperation with guest researchers from UC London. Meanwhile, a very weak carbon monoxide band has been recorded in the third overtone of the CO molecule, and further spectra have been measured in pure material, as well as in interactions...

The EUMETRISPEC initiative of WG 3.42, which aims at highly accurate determinations of molecular spectral reference data for important atmospheric gases, concentrated this year on the extension of the existing nitrous oxide (N₂O) results.

The cooperation of PTB and AVL-List GmbH – one of the world’s largest manufacturers of measurement instruments for the automotive sector – continued this year with further experiments at the diesel soot generator at PTB. Stability and reproducibility of the diesel soot generator were further improved. New operating points were determined, which are suitable to model the motoric soot emissions at...

Airborne molecular contamination (AMC) in the form of chemical vapors or aerosols have a detrimental effect on products, processes or instruments. WG 3.42 will develop a spectroscopic method within this project, which is based on the combination of direct tunable diode laser absorption spectroscopy (dTDLAS) and wavelength modulation spectroscopy (WMS), and which will aim the measurement of HCl...

The project aimed to develop humidity calibration methods and measurement techniques for air temperatures above 100 °C in industrial applications. For this purpose, TU Darmstadt has developed a laser based, absolute (dTDLAS) hygrometer, the measurement principle of which was established in accordance with those developed by WG 3.42.

The functionality of the data evaluation procedures of the FT-facility consisting of two high resolution FT-spectrometers was extended. Now, line parameters, like line position and intensity, pressure shift and broadening, and further coefficients of higher order effects (Ha-Tran-profile) can be determined from the spectrum, but also the gas temperature and the amount fraction (concentration) of...

Continuing the work after the EMRP-project EUMETRISPEC, we have generated a coherent spectral reference dataset for the important atmospheric greenhouse gas nitrous oxide (N₂O). Line parameters, which were measured by FTIR spectroscopy, can be used by remote sensing facilities for measuring N₂O concentration in the Earth’s atmosphere.

EMPIR-16ENV02 Black Carbon has been launched this summer. The project deals with the construction of a metrological infrastructure for filter-based absorption photometers, which are widely used for black carbon monitoring (environmental zones / GAW background stations).

Our WG participated this year again in two PMP-face-to-face meetings. As a result, an expert group was formed under the leadership of PTB. Our working group aims to revise the present calibration instructions for exhaust gas particle counters, that are used for calibration in industrial laboratories. In addition, the first draft of the report about the ring comparison of the exhaust gas particle...

Isotopic ratios of molecular gases like the 13C/12C ratio in atmospheric air, biological processes or industrial emissions provide important information about the sources and sinks of several materials, or about their origin. Metrological traceability of isotope standards in the form of gas mixtures is currently being discussed.

Considering the anthropogenic air pollution by emission of nitrogen-dioxide (NO₂), working group 3.22 participates in the EMPIR project MetNO₂. This project has set the development and characterization of novel NO₂ reference gas standards, as well as measurement techniques for the direct measurement of NO₂ as its main objectives.

The SEALDH-II hygrometer is a dTDLAS hygrometer based on first principles, that is capable to monitor its own “health status” with more than 80 control parameters. SEALDH-II has been used in several airborne measurement campaigns on research aircrafts.

The cooperation between PTB and AVL-List GmbH – one of the world’s largest manufacturers of measurement instruments for the automotive sector – that started in January 2015, continued with the characterization and reconstruction of a diesel soot generator at PTB. The first operating points of the diesel fueled generator have been defined. The generation of a stable and reproducible particle size...