En lärobok (främst riktad till yrkeshögskolan) om hur man undviker mätfel, om olika mätprinciper och om hur mätutrustning av olika slag bäst används och monteras. Främst handlar det om temperatur, tryck, flöde och nivå men även annat som finns i en processindustri.

The Global Geodetic Observing System, an entity under the International Association of Geodesy (IAG) has undertaken the task of advocating for the geodetic infrastructure necessary to meet the global change and other societal challenges, and defining the requirements for the geodetic observatories that constitute it. In this role, GGOS will work with the IAG Measurement Services, the scientific Community, and national and international agencies to bring a combined effort to bear on these areas of international concern. A major task within this effort is the upgrading, expansion, and maintenance of the global ground network of co-located Core Sites for geodesy to enable the realization and maintenance of the International Terrestrial Reference Frame (ITRF), Earth orientation parameters and precision orbits to meet the needs of Earth orbiting missions, Earth Surface and interior programs, and deep space navigation. GGOS and the geodetic Core Sites should be compliant with the UN resolution from Feb 26, 2015. See http://www.unggrf.org/. This Site Requirements Document outlines what is needed for that compliance.

The development of a system for determining step response of total vacuum gauges is described as well as results for some typical vacuum gauges. The system is mainly suitable for steps from atmospheric pressure down to around 50 Pa. Step response times reached with the system are (with reasonable sizes of DUT internal volumes) about 20ms.

A part of the atmosphere is ionized by the UV radiation from the Sun. This part is often referred to as the ionosphere. The resulting free electrons influence the GNSS signals as they propagate through the ionosphere. We have studied how the spatial variations of electron density in the ionosphere affect measurements with network-RTK. The aim is to predict what we can expect from measurements during the next solar maximum that is expected to occur around 2012. In order to perform a spatial characterization of the ionosphere, we have used archived GPS data from SWEPOS from a five year period, 1999-2004, around the previous solar maximum. We find that the effect of the ionospheric spatial variability on network-RTK measurements is greater during night time than during day time. It is also clear that the effect is larger for northern Sweden than for the southern part. This is especially true during night time. The effect is also largest in the months October and November and smallest in June and July. Also the number of cycle slips is larger in northern Sweden than in southern Sweden. We find that when monitoring the ionosphere and its influence on network-RTK performance it is desirable to have several different geographical regions under observation. The effects in northern Sweden may, for example not be that relevant for a user in southern Sweden. In this report we define the ionospheric delay errors as the standard deviation of the difference between the ionospheric delay at L1 at one location and the estimated value of this based on the three surrounding reference stations with 70 km separation. Using GNSS equipment that is state-of-the art around 2010, we find that when conditions are such that the ionospheric delay error is below 10 mm, which occurs some 70% of the time, a rover is able to fix the ambiguities more than 90% of the time. This ability decreases with increasing ionospheric variability and when the ionospheric delay error is larger than 25 mm, which occurs some 10% of the time, the rover ability to fix is less than 50%. When measuring with network-RTK during the next solar maximum, approximately, 80% of the time, we have conditions such that a rover has at least 75% chance of fixing the solutions. Overall the probability to find a correct fix solution when performing RTK measurements during the next solar maximum is approximately 85% and the mean time to fix is 55 seconds.

In the European Joint Research Project “Multidimensional reflectometry for industry”, a new gloss scale has been developed with the aim to represent different levels of gloss, hue, roughness and refractive indices. In this paper, the surfaces of six selected samples have been thoroughly investigated using various measuring techniques in order to verify the outcome of the novel manufacturing processes in terms of distinct levels as well as types of surface roughness. The aim of the evaluation was to capture surface structures in different wavelength intervals utilizing a confocal microscope, a coherence scanning interferometer and an atomic force microscope. Also, PSD functions calculated from the measurements have been used to determine suitability of techniques for different roughness scales. Measurements show the expected surface characteristics as well as different rms roughness values intimately connected to the perceived glossiness.

3D analysis of surface topography is becoming a more used tool for industry and research. New ISO standards are being launched to assist in quantifying engineering surfaces. The traditional optical measuring instrumentation used for 3D surface characterization has been optical interferometers and confocal based instrumentation. However, the resolution here is limited in the lateral dimension to the wavelength of visible light to about 500 nm. The great advantage using the SEM for topography measurements is the high flexibility to zoom from low magnifications and locating interesting areas to high magnification of down to nanometer large surface features within seconds. This paper presents surface characterization of dental implant micro topography. 3D topography data was created from SEM images using commercial photogrammetric software. A coherence scanning interferometer was used for reference measurements to compare with the 3D SEM measurements on relocated areas. As a result of this study, measurements emphasizes that the correlation between the accepted CSI measurements and the new technology represented by photogrammetry based on SEM images for many areal characterization parameters are around or less than 20%. The importance of selecting sampling and parameter sensitivity to varying sampling is high-lighted. Future work includes a broader study of limitations of the photogrammetry technique on certified micro-geometries and more application surfaces at different scales.

With the aim to achieve a new primary standard for calibration of ultra-low gas flows (leaks) the research in determination of gas density using optical refractometry has progressed, resulting in an evaluation of the stability of the prototype and a refined theoretical analysis. Furthermore, a renewed literature search has revealed more relevant work and further knowledge is gained from these papers. The assembled prototype was known to be of proportions far from optimum, however the assumption that it would be sufficient to reach applicable results was too optimistic. The conclusion is to continue with the efforts, however with a new and improved prototype and an adjusted choice of mirror parameters, and this report summarizes the work as of spring 2010.

The 12th comparison between the Swedish National Platinum-Iridium kilogram (Proto¬type number 40) and the principal kilogram standards for mass has been performed at SP Swedish National Testing and Research Institute. The method used was a weighted least square method with restraint developed by Dr Leslie Pendrill < >. Weighings for the pan-European key intercomparisons for 1 kg, EUROMET 509 and 510 were made together with the regular kilogram comparison.

Magnetic forces can adversely affect weighings since, without systematic investigation, these spurious forces cannot be distinguished from the gravitational forces to be compared in the determination of mass. Magnetic forces can result from the mutual interaction of two mass standards as well as between a mass standard and the mass comparator being used for the weighing. Magnetic forces arise in the influence of a magnetic field gradient on a mass standard possessing a magnetic dipole moment; the latter may either exist permanently or may be induced by the applied magnetic field. This report summarises the effects of magnetism in weighing and methods developed to determine the magnetic properties of mass standard and comparator.

Real Time Kinematic (RTK) is a system that utilises Global Navigation Satellite Systems (GNSS) to provide accurate positioning in real time. The contribution of the troposphere, the ionosphere and local effects, such as receiver noise and multipath are the most significant error sources affecting network RTK measurements We show how measurements with network RTK are affected by these different error sources under varying circumstances such as time of year or time of the day, network infrastructure, satellite systems and processing techniques We find that, for Scandinavian conditions, the effect of the ionospheric spatial variability on network RTK measurements is greater during nighttime than during daytime. The effect is also largest in the months October and November and smallest in the months of June and July. A densification of the reference network from 70 km to 35 km between the reference stations results in improved measurements. The error in the measured vertical position coordinate is reduced from 26 mm to 17 mm. The access to new GNSS reduces error in the measured vertical position coordinate from 26 to 21 mm. By using the L3-combination, the contribution from the ionosphere is reduced to virtually zero. However, this has been at the expense of the local errors

This paper focuses on the mathematical modelling required to support the development of new primary standard systems for traceable calibration of dynamic pressure sensors. We address two fundamentally different approaches to realizing primary standards, specifically the shock tube method and the drop-weight method. Focusing on the shock tube method, the paper presents first results of system identification and discusses future experimental work that is required to improve the mathematical and statistical models. We use simulations to identify differences between the shock tube and drop-weight methods, to investigate sources of uncertainty in the system identification process and to assist experimentalists in designing the required measuring systems. We demonstrate the identification method on experimental results and draw conclusions.

The key comparison EURAMET.L-K1.2011 on gauge blocks was carried out in the framework of a EURAMET project starting in 2012 and ending in 2015. It involved the participation of 24 National Metrology Institutes from Europe and Egypt, respectively. 38 gauge blocks of steel and ceramic with nominal central lengths between 0.5 mm and 500 mm were circulated. The comparison was conducted in two loops with two sets of artifacts. A statistical technique for linking the reference values was applied. As a consequence the reference value of one loop is influenced by the measurements of the other loop although they did not even see the artifacts of the others. This influence comes solely from three "linking laboratories" which measure both sets of artifacts. In total there were 44 results were not fully consistent with the reference values. This represents 10% of the full set of 420 results which is a considerable high number. At least 12 of them are clearly outliers where the participants have been informed by the pilot as soon as possible. The comparison results help to support the calibration and measurement capabilities (CMCs) of the laboratories involved in the CIPM MRA.

In this report the magnetic properties of mass standards are determined using a susceptometer. Most models used for estimation of magnetic susceptibility and permanent magnetization, with the BIPM susceptometer, are based on the assumption of a magnetic field intensity from a magnetic dipole. This field model has been compared to magnetic field intensities derived by using the Biot-Savart Law. The main conclusion is that there are no significant differences between the different models for determining the magnetic properties of the mass standards when the measurements are performed at distances larger than 17 mm from the susceptometer magnet. It is adequate to use the dipole approximation to model the field of a cylindrical magnet. Furthermore the measured results of the magnetic properties of mass standards depend on the magnitude of the magnetic field intensity. SP has during this project, participated in an international comparison for determination of the magnetic properties of mass standards. Calculations of the permanent magnetization and susceptibility agree with results obtained by other participants in the international comparison

An intercomparison of lateral scales of scanning electron microscopes (SEM) and atomic force microscopes (AFM) in various research laboratories in Northern Europe was organized by the local national metrology institutes. In this paper are presented the results of the comparison, with also an example uncertainty budget for AFM grating pitch measurement. Grating samples (1D) were circulated among the participating laboratories. The participating laboratories were also asked about the calibration of their instruments. The accuracy of the uncertainty estimates seemed to vary largely between the laboratories, and for some laboratories the appropriateness of the calibration procedures could be considered. Several institutes (60% of all results in terms of En value) also had good comprehension of their measurement capability. The average difference from reference value was 6.7 and 10.0 nm for calibrated instruments and 20.6 and 39.9 nm for uncalibrated instruments for 300 nm and 700 nm gratings, respectively. The correlation of the results for both nominally 300 and 700 nm gratings shows that a simple scale factor calibration would have corrected a large part of the deviations from the reference values.

Speed information from GPS is increasingly used and provides an alternative to conventional methods such as wheel speed sensors. We investigate the possibility to use GPS derived speed as a reference when verifying laser and radar-based speed measuring devices used in traffic enforcement. We have set up a realistic test scenario where a GPS equipped vehicle was driven at three different speeds (40, 90 and 130 km/h) through a pre-defined measurement zone. An independent and traceable reference speed was calculated by accurately measuring the length of the measurement zone (approximately 15 metres), and the time it took to pass through it. The reference speed was compared to the average GPS speed for each passage. This comparisons show that the standard uncertainty of such GPS speed measurements is less than 0.05 km/h. Hence, GPS derived speed meets the accuracy requirements for verification of laser and radar based speed measuring devices.

The key comparison EURAMET.L-K8.2013 on roughness was carried out in the framework of a EURAMET project starting in 2013 and ending in 2015. It involved the participation of 17 National Metrology Institutes from Europe, Asia, South America and Africa representing four regional metrology organisations. Five surface texture standards of different type were circulated and on each of the standards several roughness parameters according to the standard ISO 4287 had to be determined. 32 out of 395 individual results were not consistent with the reference value. After some corrective actions the number of inconsistent results could be reduced to 20, which correspond to about 5% of the total and can statistically be expected. In addition to the material standards, two softgauges were circulated, which allow to test the software of the instruments used in the comparison. The comparison results help to support the calibraton and measurement capabilities (CMCs) of the laboratories involved in the CIPM MRA.

Measurements of mechanical quantities such as pressure often take place under dynamic conditions, yet no traceable standards for the primary dynamic calibration of pressure sensors currently exist. In theory, shock tubes can provide a close to perfect step-function ideal for the calibration of pressure transducers. In this paper we investigate a system consisting of a shock tube and an ultra-fast fiber-optical sensor that is designed to be a future primary system for dynamic pressure calibrations. For reference, the fiber-optical sensor is compared to a piezoelectric sensor, and their corresponding frequency spectra are calculated. Furthermore, an investigation of the repeatability of the fiber-optical sensor, as well as a comparison with a second shock tube, is performed.

An optical method for measuring the gas density by monitoring the refractive index inside a high-finesse Fabry–Perot cavity is presented. The frequency of a narrow linewidth Er:fiber laser, locked to a mode of the cavity, is measured with the help of an optical frequency comb while the gas density inside the cavity changes. A resolution of 1.4 × 10-6 mol m-3 is achieved in 3 s for nitrogen, which allows measurement of a relative gas density change of 3.4 × 10-8 at atmospheric pressure.