Scientific news from division 1

A high-frequency personal sound exposure meter (High-Frequency and Ultrasound Personal Exposimeter - HiFUSPEx) newly developed in department 1.6 possesses the measuring capabilities of a “real” sound level meter, but as a fully portable device it can record person’s individual ultrasonic noise exposure.

The prototype of the digital calibration certificate (DCC) has been further developed. A major release has been made to the DCC. It offers extended possibilities to document e. g. formula support and conformity statements. The new version 3.0.0 became an open-source project under the Lesser General Public License (LGPL) v3.

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...

The aim of the EMPIR project 20IND13 "Sustainable advanced flow meter calibration for the transport sector" (SAFEST) is to further develop flow measurements for the transport sector in order to enable reliable, metrologically secured measurements of fuel consumption in road and maritime transport.

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.

In the EMPIR project 17IND13 Metrowamet, test rig infrastructure was developed which allows to evaluate the measurement performance of flow and volume measuring devices for realistic flow changes, e.g. in the context of water consumption. Within the framework of a EURAMET pilot study, the basis for a future extended service offer of dynamic flow calibration could be laid.

A key component of calibration facilities for traceability tasks is a secondary calibration method, which provides a way to transfer the calibration results obtained in a well-equipped standard laboratory to practical devices in the field. At PTB a sound tube apparatus has been developed, which enables this transfer for measurement devices for airborne infrasound.

Hydrometers are simple and inexpensive liquid density meters that achieve uncertainties up to 0.1 kg/m³. For this reason, hydrometers are as popular as ever! Based on their high importance for the dissemination of the density unit, a national comparison DKD-V 8-1 and a European comparison EURAMET.M.D-K4.2020 were performed.

The construction of a novel setup for hydrophone calibration was finalized by conducting extensive comparisons with further test sites at PTB. After publishing the results of these comparisons and conducting an internal audit, hydrophone calibration services up to 100 MHz can now be offered. Additionally, the results of primary calibrations are available to customers for the first time.

On 16 November 2018, the 26th General Conference on Weights and Measures (CGPM) approved a revision of the International System of Units (SI). Since the new SI was introduced on 20 May 2019, all SI units have been based on the fixed numerical values of seven constants of nature. In this new system of units, the kilogram is derived from a fixed numerical value of Planck’s constant.