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.

Consistent treatment of measurement bias, including the question of whether or not to correct for bias, is essential for the comparability of measurement results. The case for correcting for bias is discussed, and it is shown that instances in which bias is known or suspected, but a specific correction cannot be justified, are comparatively common. The ISO Guide to the Expression of Uncertainty in Measurement does not provide well for this situation. It is concluded that there is a need for guidance on handling cases of uncorrected bias. Several different published approaches to the treatment of uncorrected bias and its uncertainty are critically reviewed with regard to coverage probability and simplicity of execution. On the basis of current studies, and taking into account testing laboratory needs for a simple and consistent approach with a symmetric uncertainty interval, we conclude that for most cases with large degrees of freedom, linear addition of a bias term adjusted for exact coverage (“Ue”) as descibed by Synek is to be preferred. This approach does, however, become more complex if degrees of freedom are low. For modest bias and low degrees of freedom, summation of bias, bias uncertainty and observed value uncertainty in quadrature (“RSSu”) provides a similar interval and is simpler to adapt to reduced degrees of freedom, at the cost of a more restricted range of application if accurate coverage is desired.

The hue parameter of HSV colour-space for digital imaging is shown to be accessible for convenient quantitative fluorescence imaging. A commercially available pH probe was utilized in solution and incorporated into optical μ-sensors for microscopy applications.

Competition between iron- and carbon-based colloidal carriers for trace metals in a freshwater assessed using flow field-flow fractionation coupled to ICPMS

Internal quality control (IQC) is an essential feature of routine analysis, serving to ensure that the uncertainty of results found during the validation of a procedure is maintained over long periods of time. The primary method of IQC is to analyse a surrogate material alongside the test materials in every run of analysis and thus address run-to-run precision (a subset of VIM3-defined 'intermediate conditions'). This 'control material' must be as similar as practicable in composition to the routine test materials, although there are always some differences. Results from the control material (control values) are plotted on a control chart, and out-of-control results have to be investigated and problems rectified. Considerable care is needed in obtaining correct values of the parameters for determining statistical control limits, and these can be adequately estimated only during routine use of the analytical procedure. In contrast, target control limits have to be set on a fitness-for-purpose basis and are necessarily wider that statistical control limits. An additional type of internal quality control can be executed by the analysis of duplicate test portions of some of the actual test samples. This provides a realistic dispersion, but addresses only repeatability precision. A further complication of duplication is that the precision of results typically varies with concentration of the analyte.

The handbook provides practical guidance on sampling uncertainty estimation in the Nordtest TR handbook format. The handbook is an extract of and based upon the principles, methods and text of the international Eurachem Guide Estimation of measurement uncertainty arising from sampling. The Eurachem guide is more extensive and provides details on theory and additional examples. The basic reference for the text in this handbook is the above-mentioned Eurachem guide. The overall purpose of this handbook has been to provide those working with investigations, monitoring and control that require sampling with a set of tools for calculation and control of the sampling uncertainty of their sampling procedure. Four examples illustrate the application of different methods and tools, while allowing you to follow all steps of the calculations. Although the examples are given for specific matrices (groundwater, iron ore, baby food and wastewater) the approaches are widely applicable. It is the intention of the project group to make these tools and the understanding of their use available outside the world of analytical chemistry, although the basic principles applied originate from analytical chemistry.

A survey analysis and chemical characterization methodology for inhomogeneous solid waste samples of relatively large samples (typically up to 100 g) using X-ray fluorescence following a general homogenization procedure is presented. By using a combination of acid digestion and grinding various materials can be homogenized e.g. pure metals, alloys, salts, ores, plastics, organics. In the homogenization step, solid material is fully or partly digested in a mixture of nitric acid and hydrochloric acid in an open vessel. The resulting mixture is then dried, grinded, and finally pressed to a wax briquette. The briquette is analyzed using wave-length dispersive X-ray fluorescence with fundamental parameters evaluation. The recovery of 55 elements were tested by preparing samples with known compositions using different alloys, pure metals or elements, oxides, salts and solutions of dissolved compounds. It was found that the methodology was applicable to 49 elements including Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, La, Ce, Ta, W, Re, Ir, Pt, Au, Tl, Pb, Bi, and Th, that all had recoveries >0.8. 6 elements were lost by volatilization, including Br, I, Os, and Hg that were completely lost, and S and Ge that were partly lost. Since all lanthanides are chemically similar to La and Ce, all actinides are chemically similar to Th, and Hf is chemically similar to Zr, it is likely that the method is applicable to 77 elements. By using an internal standard such as strontium, added as strontium nitrate, samples containing relatively high concentrations of elements not measured by XRF (hydrogen to fluorine), e.g. samples containing plastics, can be analyzed.

In this study we reintroduce phase separation efficiency as an important characteristic for biodiesel quality and blending. The ability of the fuel to emulsify water is possibly one of the most important features behind biological and chemical fuel degradation but yet, no methods that directly measure this property are included in the standard biodiesel regulation EN14214. The proposed simple technique for fuel quality testing is based on the time it takes for ultra-purified water to become transparent after complete mixing with an equal volume of fuel, measured by kinetic absorbance spectrophotometry. In this study we screen the phase separation efficiency (measured as separation time) of purified, un-aged and aged Fatty Acid Methyl Esters (FAME/B100) and its blends with EN590 with 7% FAME without detergents (B7 reference fuel Euro VI Part no 546061-35 and B100) as well as for FAME blends with a commercial EN590. The B7 fuel was used as reference in all measurements. Aged biodiesel (FAME/B100) almost doubled (1.8 times) its separation time compared to the un-aged FAME/B100 sample and had almost three times (2.9) longer phase separationtime relative the reference B7 fuel. Also fuel blends showed long separation times. A fuel blend based on aged FAME/B100 blended with B7 to a corresponding B30 (30% FAME) gave after three consecutive 10 s mixings stable emulsions (>30 min) in two out of three replicates. All fuels blended with commercial EN590 showed excellent phase separation efficiencies with significantly shorter separation times than FAME/B100. We also show that the phase separation efficiency of the B30 blend could be improved after the rape seed ester was vacuum distilled before blending with B7 petrodiesel. The results indicate that likely emulsion problems associated with the B30 blends can be circumvented with proper selection of compatible petroleum components as well as FAME purifications.

The overall objective of this study was to firmly investigate if the refueling frequency influences the degradation rate of biodiesel and find out if primary and secondary oxidation products can act as initiators for biodiesel degradation in absence of metals. Duplicate samples of B7 Reference fuel Euro VI and B100 methyl rape seed ester were studied during accelerated aging in an open to dry atmosphere system at an elevated temperature (80 °C) during 14 days. Determinations of water, short chain fatty acids as well as structural changes using infrared spectroscopy were used as degradation measures during aging and complemented with total acid number and hydroperoxide concentration at the end of the experiment. The study clearly shows that there are no autocatalytic effects from left over fuel after refueling and thus, the primary and secondary products do not directly influence the degradation rate of the fuel and that the fuel quality are in fact improved after refueling as the remaining degradation products are diluted.

Clinical chemistry uses automated measurement techniques and medical knowledge in the interest of patients and healthy subjects. Automation has reduced repeatability and day-to-day variation considerably. Bias has been reduced to a lesser extent by reference measurement systems. It is vital to minimize clinically important bias, in particular bias within conglomerates of laboratories that measure samples from the same patients. Small and variable bias components will over time show random error properties and conventional random-error based methods for calculating measurement uncertainty can then be applied. The present overview of bias presents the general principles of error and uncertainty concepts, terminology and analysis, and suggests methods to minimize bias and measurement uncertainty in the interest of healthcare.