A primary air velocity meter calibration standard comprising of a precisely controlled wind tunnel system and a Laser Doppler Anemometry (LDA) system was developed for the calibration of air velocity meters from 0.2 m/s to 60 m/s with measurement uncertainties of less than 0.18% to 0.63%. The LDA system is used to verify the wind speed in the test section of the wind tunnel, and provide traceability to the SI for air speed measurements.
The article discusses the measurement of surface displacement of an electrically conductive solid material. Deflection is excited by electro-magneto-acoustic transducer (hereinafter referred to as EMAT). Measurement is realized by laser interferometer. In our research the precise surface displacement measurement is necessary for two reasons. First is EMAT transducer numerical model convergence verification, second is the experimental optimization of EMAT transducer parameters such as sensitivity, frequency and direction characteristics. Used laser interferometer allows the accurate...
During the oral application of radionuclide therapy it is from the vital importance to measure effective dose in stomach in which the Na 131 I therapeutic capsule stays during the 15 minutes which is long enough to make risky exposure. As it is not possible to determine it by direct measurements there is a strong recommendation to estimate the dose by calculation. The main goal is to calculate effective dose and risk as a result of 131 I capsules remaining in stomach before the absorption starts. Monte Carlo code MCNP4b was used to model the transport of gamma and beta particles emitted by...
One among factors responsible of the instability of mass standard is the adsorption and desorption induced by the cleaning products. An optical non-contact method based on mirage effect is proposed to investigate the adsorption/desorption of cleaning solvents on the surface of mass standards at conditions close to normal temperature and pressure (NTP). A model developed for the mirage effect when physical adsorption occurs on a non-porous sample under NTP conditions is recalled. The experimental results of the mirage deflection obtained, in the case of platinum iridium alloy with ethanol...
The purpose of this work is to contribute for the metrological traceability statement of chemical measurements. Traceability statement for total chromium mass fraction in serpentine soils was developed. Accordingly, the quantity values requiring a high degree of control are calibration and quality control standard solutions, matrix certified reference material and the calibration curve model fit.
This paper deals with the influence of the flat surface temperature probe measuring temperature. Different measurement approaches for measuring surface temperature are possible. For the purpose of safety testing of household appliances surface temperature measurements are very important. General requirements are presented in European standards, which support requirements in European Low Voltage Directive 2006/95/EC. Paper introduces comparison of temperature measurement between attached thermocouple on the measured surface and measurement with flat surface temperature probe. As a heat...
The scope here is to derive a model of the measurement error of static energy meters. The model proposed is based on three error parameters: gain, phase and bias error. The validity of the model is confirmed through the statistical analysis of the measurement results obtained during the calibration of a commercial energy meter, compliant with the Measuring Instruments Directive 2004/22/EC. The experiments also involved operating conditions of the meter beyond those required by the calibration procedure prescribed by the relevant standards. A further analysis is offered aimed at verifying the...
In this paper the magneto-elastic effect is taken under further investigation, to determine the utility of the novel material Terfenol-D in force sensor applications. A measurement set-up is designed and the characteristic material parameters like magnetization diagram, butterfly diagram and the reluctance dependent on the applied mechanical load is determined. The results demonstrate that it is possible to sense both static and dynamic forces with only a single read out coil. The resultant simple arrangement of the set-up combined with the not fully utilized overload capability given by the...
Measuring equipment is often complex and expensive. So training on a simulation in virtual experiments is in many cases a good idea, especially if it is conducted over the internet. On the other hand, mathematical models, needed for the simulation of a complex measuring device and complex measuring phenomena have limited efficiency. For this reason a remote control of the real equipment, in this particular case the oscilloscope, is presented in this article. The training efficiency is increased by time sharing the instrument over the internet. Another goal was also to develop a realistic...
Advanced control of Coriolis Mass Flow Meters (CMFM) is crucial in situations with multiphase flow and absolutely necessary to prevent the meter from stalling. A high dynamic response of the meter is also of great importance in order to realize advanced features s.a. parameter identification for self-diagnosis or detection of changes in sensitivity and zero. In [4] a cyclic stimulation of the coriolis-mode of the CMFM, representing a virtual mass flow, is presented for generating diagnostic data and marks a major step towards the realization of such features. The presented phasor control...