9762 papers found
Paper presents some practical aspects of excitation coil design for electromagnetic flow meter dedicated for open channels. Two types of coil is discussed, saddle type and double deck type. Some minor and major differences are discussed.
Windows are frequently used in digital signal processing, mainly for leakage reduction in non-coherent sampling (spectral analysis, detection of weak harmonic components close to a strong harmonic components, e.g. in ADC testing) or in FIR digital filter design. Many windows are described and compared in literature. This paper informs about a mathematical instrument and an algorithm allowing design of several classes of cosine windows with various prescribed properties. The design is based on iterative window spectrum zeros placing. Window coefficients are presented either as high-accuracy...
Nowadays leak detection is widely used in various fields such as the automotive and the refrigeration industries. In France, the leak tightness of installations charged with refrigerants must be controlled periodically by refrigerant detectors, whose sensitivity thresholds are qualified according to several tests described in the European standard EN 14624. The tests described in the European standard are mainly a comparison between the detector signals and several appropriate calibrated leaks. In order to ensure the traceability of the calibrated leak flow rates, a project involving the...
Radiofrequency methods and devices for on-line measurement of technological parameters of liquefied petroleum gas (LPG) in a pipeline are suggested. RF temperature-independent LPG density measuring device is considered. Designed automated system for determination of LPG density and water content under LPG pipeline transportation and water removal from LPG is described.
The purpose of this research is improving so that the result of blood chemical analysis (BCA) can be assured. It can be useful for clinical diagnosis. It is also included. ISO-GUM was created as guidance for making an analysis result into an assurance performance. In supplement 1 of ISO-GUM (ISO-Guide to the express of uncertainty in measurement) in detail, it recommended using Markov Chain Monte Carlo (MCMC) for "law of propagation of the uncertainty (LPU)". The main features of ISO-GUM changed the mode of expression of an analysis result into uncertainty from error, and processing of data...
The calibration of radiation thermometers requires knowledge of the target size effect on the thermometer output, namely the size of source effect (SSE). The measurement of an instrument SSE allows to calculate a correction, or an estimation for this source of uncertainty. For a correct determination of SSE it is necessary to use large aperture radiation sources of uniform spectral radiance. We show here an experimental system to measure SSE at high temperature (up to 600 °C) with an enough large aperture of broad band radiation thermometer with output in terms of temperature.
Knowledge of the transfer function of a force transducer is required in order to determine a transient force from the transducer's output signal. We describe a linear least-squares fit method for system identification to estimate the transfer function from sinusoidal force calibration measurements, and we consider the evaluation of uncertainty associated with the obtained estimate. In applying this method to different calibration measurements it is demonstrated that consistent results are obtained for the transfer function.
It is described how to calibrate the kinematic parameters of a parallel CMMs, in this paper. The artefact which consists of spheres is selected as physical constraints for self-calibration. The kinematic calibration of the parallel CMM is performed using the artefact of two spheres. The parallel CMM can measure a sphere in a lot of different orientations so that a lot of sensor information can be got at the identical location. If the number of sensor information is larger than that of whole parameters, e.g. the kinematic parameters and the orientation and location of stylus, the whole...
The most important principles, the basis and operation of heterodyne and homodyne interferometers are discussed. Their benefits and limitations are covered based on a metrological analysis. The resolution of interferometers can be determined by calculating the smallest resolvable distance increment. Also, it is shown here how the Abbe comparator principle can be fulfilled in all three measuring dimensions by using interferometers. Other factors in addition to the Abbe errors are discussed which affect the measurement uncertainty of interferometric length measurements. The Abbe-error-free...
Roundness measurement capability and traceability at the National Institute of Metrology (Thailand), NIMT, is discussed here. RTH Talyrond 73 HPR is used to measure various roundness parameters of the specimen. The modifications of the measurement system and analysis software were employed in order to perform roundness measurement based on multi-step method. This technique enables us to separate roundness error of the workpiece from the spindle error of the instrument. The measurement uncertainty for the glass hemisphere calibration using multi-step method is Q[8, 8 R ] nm where R is the...