IMEKO Event Proceedings

Page 7 of 748 Results 61 - 70 of 7479

Gustavo P. Ripper, Guillermo Silva-Pineda
A bilateral acceleration comparison between CENAM and INMETRO

A bilateral key comparison was conducted in the area of vibration between the National Institute of Metrology, Standardization and Industrial Quality (INMETRO), Brazil and the Centro Nacional de Metrología (CENAM), in Mexico; with INMETRO acting as pilot laboratory. This comparison was registered in the BIPM key comparison database (Mutual Recognition Arrangement - Appendix B) as SIM.AUV.V-K1.1 and the measurements were carried out by the participating laboratories from October 2004 to March 2006. The aim of this exercise was to compare primary interferometric measurements of complex charge sensitivity of standard accelerometers under sinusoidal linear accelerations in the frequency range from 10 Hz to 10 kHz. In addition, it was intended to provide a link between INMETRO and the key comparison reference values (KCRVs) established in the CIPM key comparison CCAUV.V-K1. This link of the regional metrology organization (RMO) key-comparison SIM.AUV.V-K1.1 to the International Committee for Weights and Measures (CIPM) key-comparison CCAUV.VK1 can be established because CENAM participated in both comparisons. Both participants used automated calibration systems based on homodyne quadrature laser interferometers to measure the sensitivity magnitude and the phase shift of two backto- back standard accelerometers in compliance with the international standard ISO 16063-11:1999.
The results reported by the participating laboratories at 30 specified frequencies and the respective calculated degrees of equivalence are presented. These results show an agreement better than 0,3 % from 10 Hz to 5 kHz and than 1% from 6 kHz to 10 kHz in sensitivity magnitude and better than 0,6D in phase shift in the entire frequency range.

Luca Callegaro, Jan Vejdelek
A Bridge for High-frequency Capacitance Scaling

A bridge, suitable for 1:1 and 10:1 ratio measurements of four terminal-pair impedances to frequencies up to 5 MHz, has been constructed and is presently under testing. The purpose of the bridge is to extend the Italian national standard of capacitance toward higher frequencies; however, the bridge will be employed for resistance comparisons also. Expected best uncertainty is in the order of a few parts in 10-5 for 10 nF - 1 nF ratio measurements, at 1 MHz.

Vadim Geurkov
A BUILT-IN SELF-CHECK METHOD FOR MULTI-CHANNEL MEASUREMENT SYSTEMS

Signature analysis techniques have become extremely popular in digital systems testing due to such advantages as simplicity, small amount of additional circuitry, and small degree of error masking. In this paper the signature analysis techniques are applied to mixed (analog-to-digital) systems testing. The general case of multi-channel measurement system is considered.

Andrzej Miekina, Roman Z. Morawski
A CALIBRATION METHOD, BASED ON RIDGE LS ESTIMATOR DESIGNED FOR DETERMINATION OF OLIVE OIL MIXTURES ON THE BASIS OF NIR SPECTRAL DATA

The spectrophotometric analysis of oil mixtures, containing olive oil, is the subject of this paper. Its objective is to propose and evaluate a new methodology for determination of a selected component of such a mixture. According to this methodology, the space of concentration values to be estimated is partitioned into subspaces and the calibration is performed separately for each subspace by means of a new piecewise ridge least-squares estimator. The estimation of concentrations is carried out, using the results of calibration, in two cycles: first, rough estimates of concentrations are found and a corresponding subspace is identified; next, the results of calibration, obtained for this subspace, are used for refining the estimates of concentrations. The performance of the proposed methodology is assessed using a criterion related to measurement uncertainty.

T. Dunker, S. Sperling
A CALIBRATION STRATEGY FOR SYSTEMS WITH 2-D LASER SENSORS

We consider measuring machines (MMs), which use one ore more 2-D laser sensors (2-DLSs) for automated dimensional inspection. In order to transform several measurements from their sensor coordinate frame (CF) into a world or object CF, we need a parameterized model of these transformations. We present a method, which allows for very different MMs to set up a model, to construct a calibration object and to estimate the model parameter from measurements on the calibration object.

C. Hirunyapruk, P. Rattanangkul, B. Thummawut, V. Plangsangmas
A CALIBRATION SYSTEM FOR LASER VIBROMETERS AT NIMT

Laser Vibrometers have been used in many applications such as automotive and hard disk drive industries. In metrological field, laser vibrometers are employed as reference standards for the calibration of accelerometers. To have the traceability chain to the International System of Units (SI), several National metrological institutes (NMIs) and companies have developed calibration systems for laser vibrometers. National Institute of Metrology (Thailand), NIMT, is one of those NMIs. This paper describes the set-up for the primary vibrometer calibration system used at NIMT and presents the methods used according to methods 1 and 2 shown in the international standard ISO16063-41. The calibration results are also discussed.

Sari Semenoja, Martti Heinonen
A calibration system for PTU devices

Devices measuring pressure, temperature and humidity simultaneously are known as PTU devices. There are hardly any commercial calibration systems for the PTU devices available for low temperatures (< 0 °C). To obtain more comprehensive data on the performance of PTU devices, a new calibration system is developed at MIKES. In this PTU Apparatus, pressure, temperature and humidity can be controlled simultaneously so that all combinations over the ranges are possible. The nominal ranges of the system are the following: absolute pressure 500 hPa … 1200 hPa, temperature -52 °C … +80 °C and relative humidity 10 % … 95 %. The estimated uncertainties (k = 2) of the pressure, temperature and humidity are 10 Pa, 0,1 °C to 0,3 °C and 1 %RH to 3 %RH, respectively. The construction and operation as well as the results of operational tests of the PTU Apparatus are reported in this paper.

Georgiana Moraru, Marcel Istrate
A Case Study In Water And Wastewater Systems’ Energy Efficiency

World economy is closely related to energy and to how it contributes to the modernization of the society, by raising the standard of living and the degree of civilization of the population. In this context, water supply systems are attractive for energy efficiency, occupying an important place in the hierarchy of energy consumers. The purpose of this paper is to present some important aspects of a case study that must be considered in order to respond to specific requirements of water supply systems and it also shows a few measures that can be implemented with or without investments in order to reduce costs and energy consumption.

Cristiano Benedetto De Vita
A Case Study of Agrarian Assets in the Territory of Caere (6th-5th century BC)

The present paper defines some approaches employed to study the agrarian landscape of the Etruscan city of Caere.The aim is to verify some features of rural infrastructures of this territory, which has been planned systematically since the end of the 7th- early 6th century BC. Through the use of different approaches – from the archaeomorfology to the metrology, to the aerial photo interpretation – the research seeks to verify those signs suggesting systematic and symmetrical forms of occupation of the Caeretancountryside, as an effect of an articulated plan imposed by the city at the time of its greatest expansion. The results, still under development, show the constant recurrence of distances and orientations, with variations often related to the characteristics of the territory or the needs of community exploitation.

Helena Ramos, M. Pereira, V. Viegas, O. Postolache, P. Girão
A CENTRONICS BASED TRANSDUCER INDEPENDENT INTERFACE (TII) FULLY COMPLIANT WITH 1451.2 STD.

The paper reports the tests conducted on a dedicated Transducer Independent Interface (TII) to check its compliance with standard IEEE 1451.2 specifications. The interface was built using a synchronous data transfer based on the Serial Peripheral Interface (SPI) protocol integrated in a PIC microcontroller used as the Smart Transducer Interface Module (STIM) and the Centronics port of the PC, used as the Network Capable Application Processor (NCAP’s TII port). The description of each line and the connections are also presented.
The working prototype of the STIM controlled by a NCAP module was implemented to connect several transducers without communication capabilities used in a water quality monitoring network. The NCAP, also described in the paper, is emulated in a PC and it was fully developed using LabVIEW 6.1.

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