News of the Year

A long-term comparison of two optical ytterbium clocks has confirmed the fundamental hypothesis of Einstein's Theory of Relativity according to which the speed of light is always the same, no matter what the conditions are.

PTB’s researchers, together with international colleagues, have secured a prestigious Synergy Grant from the European Research Council (ERC) for the development of an entirely new atomic clock – the thorium nuclear clock. A thorium nuclear clock could be significantly more accurate than all the previous caesium clocks and – also – than all the previous optical atomic clocks.

Medicine is placing high expectations on implants and auxiliary materials that are manufactured specifically for each individual patient. Nearly any complex shape can be produced by means of additive manufacturing (3D printing). Before starting to use such implants widely, the medical sector and certification bodies demand proof of the fact that their high quality is matched and will remain stable...

Advances in radiation therapy are leading to ever better ways to irradiate even small tumors precisely and to spare the surrounding tissue. For this highly exact task, radiation devices and radiation plans are metrologically verified by means of therapy dosimeters before use on patients. New, very small dosimeters which are appropriate for this application were at the focus of PTB’s research:...

Scientists from PTB have implemented a novel method for pressure measurement – quasi as a byproduct of the work on the "new" kelvin – and have reported about it in Nature Physics. The method is based on measuring the density of the measuring gas helium by means of a capacitance measurement. The degree to which gas between the electrodes changes the capacitance of a highly stable, special...

The concentration of pathogenic microorganisms is an important parameter when medical decisions need to be made. the number of microorganisms (e.g. viruses or bacteria) can be determined by counting certain genetic sequences in a sample. The digital polymerase chain reaction (dPCR) is a method that is perfectly suited to counting these genetic sequences directly and to measuring concentration in a...

In mammography screening, the risks posed by the X-rays used must be carefully weighed against the potential gain of a timely breast cancer diagnosis. e rule of thumb: the higher the applied radiation dose, the better the resulting image quality and, therefore, the greater the likelihood of reliably recognizing breast cancer at an early stage. For this reason, an objective measure of image...

Magnetic resonance imaging (MRI) is an important imaging procedure in cardiology. To date, only qualitative imaging of the heart has been possible with MRI, since the measuring time is limited due to heart movements and breathing. A new image reconstruction procedure has therefore been developed at PTB. This method quantifies the biophysical parameters of the cardiac muscle with high spatial...

As regards the worldwide harmonization of the certification of legally regulated measuring instruments, the year 2019 can be considered as a thoroughly successful year: By the end of the year, 37 measuring instrument categories had been covered by the new certification system of the OIML (Organisation Internationale de Métrologie Légale), and more than 350 certificates had been issued.