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<p>The Hall-effect based Teslameters (also called Gaussmeters) are the mostly applied instruments for measuring DC and AC magnetic flux densities in modern science and industry. This paper gives an overview of commercially available Teslameters at the high-end performance level. The Teslameters have been evaluated by following characteristics that are published by suppliers: probe dimensions, magnetic field sensitive volume, accuracy, magnetic resolution, measurement range, frequency bandwidth, temperature coefficient sensitivity, and price/performance ratio.</p><p>The Teslameter that best matches the measurement needs in various application fields incorporates a 3-axis integrated Hall probe, analog electronics based on the spinning-current technique, an analog-to-digital converter, an embedded computer, and a touch-screen display. The 3-axis Hall probe is a single silicon chip integrating both horizontal and vertical Hall magnetic sensors and a temperature sensor. The spinning-current eliminates most of the Hall probe offset, low-frequency noise, and the planar Hall voltage. The errors due to the Hall sensor non-linearity and the variations in the probe and electronics temperatures are eliminated by a calibration procedure. The errors due to the angular imperfections of the Hall probe are eliminated by a calibration of the sensitivity tensor of the probe. This Teslameter can measure magnetic field vectors from about 100 nT to 30 T, with the spatial resolution of 100 µm, magnetic resolution ±2 ppm of the range, the accuracy 0.002 % of the range, a temperature coefficient less than 5 ppm/°C, and angular errors less than 0.1°.</p>

In the framework of the SwissFEL project at the Paul Scherrer Institute (PSI), a Hall probe bench is being developed for the high-precision magnetic characterization of the insertion devices for the ATHOS soft X-ray beamline. For this purpose, a novel three-axis teslameter has been developed, which will be placed between the undulator and its outer shell in a very limited volumetric space of 150 x 50 x 45 mm. Together with a Hall probe at the center of the cross sectional area of the undulator, the setup will traverse along the undulator length on a specifically designed rig with minimal vibrations. This teslameter has all the analog signal conditioning circuitry for the Hall probe and also has on board 24-bit digitization. The instrument also handles an interface to a linear absolute encoder. The old instrumentation used only had analog signal conditioning circuitry whilst digitization was done off board. The new instrument also provides a very accurate magnetic field map in the µT range with simultaneous readings from the position encoder at an accuracy of ±3 µm. In this paper, a series of tests are described, which were performed at PSI in order to establish the measuring precision and repeatability of the instrument.

Hall effect based Teslameters/Gaussmeters measure DC and AC magnetic flux densities in the range from a few µT to about 30 T. For accurate measurement a 3-axis Hall probe is applied with small magnetic field sensitive volume (MFSV) of 100 µm × 10 µm × 100 µm, with vertical and horizontal Hall elements integrated on a single chip. The planar Hall effect, that produces additional measurement errors is suppressed by the spinning current technique. The orthogonality error of the 3-axis Hall probe is reduced to smaller than 0.1° by the described calibration procedure. This paper explains why the above features are crucial for some applications in industry and modern science for accurate measurement of inhomogeneous magnetic fields and how to achieve them. The future technology trends in magnetic metrology are introduced and the newly developed Nanomapper that incorporates a 3-axis Hall probe with a MFSV of smaller than 10×10×10 micrometer is presented.

This is a study of the process of the development of high-tech start-up companies through the mechanisms of bootstrapping in two extremely different environments: the one of highly industrialized countries, such as USA and Switzerland; the other of Serbia, which is a post-communist transition country with particular difficulties. The research method is the analysis of case studies. One case study of US and two of Swiss start-ups build the base for the analysis. All three cases show common patterns: from the very beginning, these companies sell R&D services in their fields of expertise; and using the cash from these early sales, and the information feedback from cooperation with the early customers, they develop their resources and, eventually, also their own high-tech products. The essential feature of this process is the selling of R&D services and the first products in the neighborhoods. Then also two cases of high-tech start-ups from Serbia are analyzed. Both Serbian start-ups are founded in partnership with small high-tech companies from highly industrialized countries (Switzerland and Germany). The Western partners use their reputations and contacts to enable the early sales of the Serbian start-ups in the industrialized countries. This is crucial for the Serbian start-ups, because they have no domestic market for R&D services. Apart of this element, all other essential patterns of the Serbian cases are very similar to those of the Western cases.