Education and training of laboratory staff as a part of laboratory competence

Competence of laboratory staff is an important part of the technical competence of each laboratory. Because the speed at which knowledge goes out of date is increasing, maintaining laboratory staff competence at an appropriate level can be a very demanding requirement, especially for laboratories operating in a free market with little or no financial help from the state or from the larger organisation they possibly belong to. In order to manage staff competence effectively and efficiently, a laboratory must first define its services and the processes needed for realisation of these services. Responsibility for each step in these processes can then be assigned and gap analysis of current competence can be performed. This article analyses the requirements of ISO/IEC 17025 standard and gives some practical advice and solutions how to organize and manage staff competence.     

基于IS015765的电动汽车诊断系统设计

为了更加便捷地对电动汽车进行程序更新和故障诊断,开发了符合ISO15765的底层刷写协议栈。参考BOSCH ECU在线刷写流程拟定XC2000刷写流程,包括初始化、密钥认证、Flash分区擦除、Flash分区写入等过程。开发XC2000 Flash驱动,实现Flash按地址进行块擦除和写入,开发Bootloader,实现硬件资源初始化以及ISO15765协议栈的装载。开发了符合ISO15765的底层刷写协议栈,实现故障码读取、故障码清除、数据流读取、执行器测试等故障诊断功能。开发了电动汽车诊断上位机系统,并通过硬件在环仿真测试平台进行测试。测试结果表明,设计的电动汽车诊断系统利用CAN总线能够实现ECU在线刷写及故障诊断功能。     

The prediction of airborne sound transmission between two rooms using first-order flanking paths

Airborne sound transmission between adjacent rooms can be predicted using the Standard EN 12354-1 (ISO 15712-1), which is equivalent to a first-order approximation of statistical energy analysis (SEA). This paper analyses airborne sound transmission between adjacent rooms in a masonry building, by comparing results obtained from EN 12354-1 to SEA predictions and measurements. It is shown that the restriction of the Standard to first-order flanking paths can lead to large errors in predictions when compared to measurements and SEA results taking into account all transmission paths. This is observed both for individual flanking paths and overall transmission between rooms, for which the Standard provides results similar to those obtained by the first-order approximation of SEA. The paper also looks at possible reasons why previous studies using the approach in EN 12354 have generally shown good agreement with measurements.     

Characterization and improvement of absorption and scattering by profiled architectural surfaces without specialized test facilities

A turntable apparatus and measurement procedure, based on ISO 17497-1, were developed for measuring the random-incidence absorption and scattering of surfaces, without specialized facilities. While not highly accurate, they proved adequate for determining the general characteristics of surfaces. Two original profiled wooden architectural surfaces, and a hard, flat reference surface, were characterized, and found to have low absorption and scattering. They were then modified for increased absorption by creating Helmholtz-resonator configurations, obtaining good performance at low- and mid-frequencies. They were also modified for increased scattering, in one case by creating a Schroeder diffuser. In the other case, the surface was integrated into a novel frame-array configuration, which scattered sound very well above 500 Hz.     

X-ray tube spectra measurement and correction using a CdTe detector and an analytic response matrix for photon energies up to 160 keV

The aims of our work were: i) to measure selected normalized X-ray beam spectra with the commercially available cadmium telluride detector based spectrometry system; ii) to construct the approximate response matrix of the detector using a simple algebraic model approach; iii) to reconstruct the physical energy spectra from the measured instrumental spectra using the detector response matrix; iv) to compare the obtained spectra parameters with the published and reference data in order to verify the model and to optimize the measurement setup if necessary. In particular, the spectra of five “narrow-spectrum series” beams, namely N60 to N150, were measured with a spectrometry system consisting of the Amptek XR-100T X-ray semiconductor detector and the PX5 multichannel analyser. Two different measuring geometries were used. The response matrix R(E, E′) of the detector was constructed which quantifies the energy dependence of the relative detection efficiency of the detector, the probabilities of the escape effects, and the probability of the Compton effect. A single matrix operation was applied to recover the physical energy spectra from the measured instrumental ones. The parameters of the corrected spectra were compared with the published and reference data. Despite the fact that the effect of incomplete charge collection was not implemented in the detector model, a fully satisfying quantitative correspondence was observed between the measured corrected spectra and the available reference data.     

Sample preparation methods for subsequent determination of metals and non-metals in crude oil—A review

In this review sample preparation strategies used for crude oil digestion in last ten years are discussed focusing on further metals and non-metals determination. One of the main challenges of proposed methods has been to overcome the difficulty to bring crude oil samples into solution, which should be compatible with analytical techniques used for element determination. On this aspect, this review summarizes the sample preparation methods for metals and non metals determination in crude oil including those based on wet digestion, combustion, emulsification, extraction, sample dilution with organic solvents, among others. Conventional methods related to wet digestion with concentrated acids or combustion are also covered, with special emphasis to closed systems. Trends in sample digestion, such as microwave-assisted digestion using diluted acids combined with high-efficiency decomposition systems are discussed. On the other hand, strategies based on sample dilution in organic solvents and procedures recommended for speciation analysis are reported as well as the use of direct analysis in view of the recent importance for crude oil field. A compilation concerning sample preparation for crude oil provided by official methods as well as certified reference materials available for accuracy evaluation is also presented and discussed.     

Development and accreditation to ISO/IEC 17025 calibration status of a melting point measurement facility for the UK

A melting point measurement facility for the UK has been developed and accredited to ISO/IEC 17025 Calibration status for the determination of the liquefaction temperature of pure substances from 35 to 250°C. The facility is based upon a commercial instrument, i.e. an oil bath fitted with an aluminium block (Isotech, model 798 EHT), a precision multimeter (Isotech TTI-7), a thermocouple directly inserted in the sample under investigation and a platinum resistance thermometer (PRT) tracking the block temperature. The homogeneity of temperature bath/block was investigated and the PRT used for the traceability of the measurements was calibrated by NPL and traceable to ITS-90. The process was validated using four current LGC Certified Reference Materials (CRMs):