IMEKO Event Proceedings

Page 848 of 866 Results 8471 - 8480 of 8655

Steffen Seitz
Verification of the metrological Reliability of Standard Seawater Calibration

The calibration of standard seawater, the most relevant standard for worldwide Practical Salinity measurements, is based on a conductance ratio measurement of standard seawater and a defined KCl solution. The results of an interlaboratory comparison measurement of such conductance ratios are presented at various salinities (7, 19, 35) and temperatures (5, 15, 25, 35 °C). The comparison reveals a dependence of the conductance ratios on the measurement systems that is larger than the uncertainty currently assigned to Practical Salinity measurements. This jeopardizes long term continuity of Practical Salinity measurements, if the type of instrument currently used for standard seawater calibration should not be available one day. There is a need for a metrological network for oceanographic observables to put Practical Salinity measurements on a sustainable metrological ground.

Harald Kohlhoff, Christian Ullner

A new calibration machine according to the requirements given by ISO 14577-3 [1] was described in [2]. The results of the verification are reported in this paper. It is shown that the calibration machine can be used as a national standard for the materials parameter of the instrumented indentation test.

Nae Hyung Tak, Gun Woong Bahng, Tag Gyu Kim

The indicating device of a Leeb hardness tester is an important device that determines the performance of tester. As such, the indicating device needs verification just like the depth-measuring system of a Rockwell hardness tester. This paper presents the verification results of indicating devices from different manufacturers. For the verification, a calibrator to output the reference voltage signal was designed and used for the test. The results showed that the maximum deviation was 24 HLD.

Rostyslav Mastylo, Thomas Froehlich, Eberhard Manske

Big challenges in precision measurement technology nowadays lead to the creation and improvement of a big variety of optical and tactile probes. This development concerns a nanosensor system on the basis of a non-contact laser focus probe (base sensor) which presents high resolution and low uncertainty. Optical and mechanical probing methods are combined on the basis of a laser focus sensor, thus allowing the combination of various interactions between sensor and specimen. For these purposes, the deflection of the probing sensor (cantilever or stylus) is measured directly without contact using the laser beam of the focus sensor. The significant advantage of the developed nanosensor system results from its modularity and versatility. Scanning laser focus sensors are a viable alternative enabling the measurement of non-periodic features. Severe limitations are imposed by the diffraction limit determining the edge location accuracy. A rigorous model for the simulation of the diffraction of three-dimensional focussed optical beams from line space patterns has been developed and applied to improve the edge detection accuracy of a laser focus sensor. The validation of this method is realised by means of an AFM part of the nanosensor system.
Moreover, the possibility of using the laser focus senor not only for precision measurements, but also for the direct generation of precision nanostructures by means of lithography can be shown. Here, compared with classical lithography the goal is to ensure the capability of processing freeform structures on tilted surfaces.

Luis Reyes Rosales Montero

The objective of this work is to describe a versatile multifunction electrical digital meter based on personal computer; it has been developed for incorporation into a laboratory testing system. The meter uses two 12-bit A/D. The A/Ds are connected to parallel printer port of PC. The work was developed for Measurement of power. Using a programming language Turbo C++ was calculated: rmsVolts, rmsAmps, volt-amps, Reactive Power, Phase angle, frequency, Active power, watts-hour, resistance, capacitance and period. The values are shown at the monitor as a 4-digit display. The accuracy of meter is within 0.1%. The virtual power meter has a virtual two-channel oscilloscope. The meter was developed to senses power supply of electronic devices. (TV, PC) and electromagnetic device.

Liviu Breniuc, Constantin Sarmasanu, Mihai Cretu, Cristian Gyözö Haba

In this paper we present a frequency-meter based on the method of reciprocal frequency-meter. For the implementation of the frequency-meter we have used an FPGA and a microcontroller. We have measured frequencies between 0.05 Hz and 10MHz. The measuring ranges are: 0.05 Hz to 0.5 Hz, 0.5 Hz to 5 Hz and 5 Hz to 10 MHz. The measurement times for the corresponding ranges are: 20 to 10 s, 2 to 1 s and 0.2 to 0.1 s respectively. The base error of the frequency-meter is 2·10-6.

E. M. Graham, M. Reader-Harris, G. Chinello, K. Harkins, N. Bowman, L. Wales
Vertically installed Venturi tubes for wet-gas flow measurement: possible improvements to ISO/TR 11583 to extend its range of applicability

Venturi tubes are commonly used for wet-gas flow measurement, and the majority of commercial wet-gas flow meters generally include a Venturi tube installed vertically with embedded secondary instrumentation. The presence of the liquid causes an increase in the measured differential pressure and results in the Venturi tube over-reading the actual amount of gas passing through the meter. Most of the research in the literature is focused on the investigation of the over-reading for horizontally oriented Venturi tubes, thus limiting the development of over-reading correlations for vertical installation. An experimental campaign was recently conducted at the National Engineering Laboratory (NEL) high-pressure wet-gas loop, where three Venturi tubes of the same nominal diameter (4”) but different throat to inlet diameter ratio (0.4, 0.6, 0.75) were tested, installed vertically after a blind tee. The results of this experimental campaign are presented in this paper and the effects of various parameters (line pressure, gas Froude number, diameter ratio) on the over-reading are briefly discussed. It is shown that the over-reading correlation included in the ISO/TR 11583:2012 and developed for horizontally oriented Venturis, is not applicable to vertically oriented Venturis. However, if modified, the correlation included in the ISO/TR 11583 is capable of meeting its stated uncertainty limits for the experimental data presented here for vertically installed Venturis.

Jérémy Postel-Pellerin, Gilles Micolau, Philippe Chiquet, Jeanne Melkonian, Guillaume Just, Daniel Boyer, Cyril Ginoux
Very low tunneling current measurements using the Floating-Gate technique in a very low-noise environment

In this paper we propose and develop a complete solution to measure very low tunneling currents in Non-Volatile Memories, based on the Floating-Gate technique. We aim at using very basic tools (power supply, multimeter, ...) but still having a very good current resolution. The key node of our solution is that the experiment is led in a very particular low-noise environment (underground laboratory) allowing to keep the electrical contacts on the device under test as long as possible. The aim of this work is to show both the feasibility of such measurements and the ability to reach current levels lower than the ones obtained by any direct measurement, even from high-performance devices such as HP4156 or Agilent B1500 with atto-sense and switch unit (ASU). We have demonstrated the feasibility of this approach and obtained a very promising 10−17A current level in less than two weeks.

S. Del Pizzo, S. Gaglione, A. Angrisano, G. Salvi, S. Troisi
Vessel attitude estimation by camera sensors

Vessel attitude is one of the most sensitive information in important operation. For instance, during ship cargo loading or discharge operation an un-accurate estimation of vessel attitude could compromise the safety of the procedure. Ship pith and roll parameters are directly measured by traditional sensors (bubble levels) or indirectly estimated from ship motion monitoring. Also inertial sensors, that provide a continuous attitude information, are actually used in offshore riser monitoring and dynamic positioning systems but not spread in all commercial ships. The aim of the proposed study is to provide vessel roll and pith using a cheap technology just widespread in shipping. This work presents the project of an embedded solution that uses visual information, captured by a consumer camera that “looks” the horizon. The camera system is constrained to the ship hull, while a computer unit is able to detect and track the horizon line, that fall within the image bounds. The paper describes how the horizon’s movements provide pitch and roll angles, furthermore, in order to perform an accuracy analysis, several static tests were carried out.

Z. Ismail, R. Hayu, H. Sutanto, Hafid

A study to identify the effect of changes in vessel cross-sectional area to the mass evaporation rate of micropipette calibration without evaporation trap at nominal value of 20 µl is still being tested. Three different vessels with various diameter values of 5.9 mm, 9.8 mm and 13.7 mm were used to determine their effect to evaporation. The result of the test showed that the smaller diameter of vessel reduced the mass evaporation rate on micropipette calibration.

Page 848 of 866 Results 8471 - 8480 of 8655