Search results for " Instrumentation."
showing 10 items of 712 documents
Influence of root canal instrumentation and obturation techniques on intra-operative pain during endodontic therapy.
2012
Objective: To analyse the influence of root canal instrumentation and obturation techniques on intra-operative pain experienced by patients during endodontic therapy. Method and Materials: A descriptive cross-sectional study was carried out in Ponferrada and Sevilla, Spain, including 80 patients (46 men and 34 women), with ages ranged from 10 to 74 years, randomly recruited. Patient gender and age, affected tooth, pulpal diagnosis, periapical status, previous NSAID or antibiotic (AB) treatment, and root canal instrumentation and obturation techniques were recorded. After root canal treatment (RCT), patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain. Results…
Uncertainty Management in the measurements performed by means of virtual instruments
2008
The uncertainty management is the discipline of optimising the cost of a measurement versus the uncertainty target. In particular, the paper deals with the measurements performed by using a generic virtual instrument. The task is achieved by using the PUMA (procedure for uncertainty management) method that is an iterative technique originally conceived for geometrical and mechanical measurements. The approach is completely based on the "guide to the expression of uncertainty in measurement" rules, but provides a more engineering methodology, since it allows to optimize the cost of the measurements versus the uncertainty target, avoiding the use of inadequate or, on the contrary, too expensi…
Can the effective number of bits be useful to assess the measurement uncertainty?
2003
The effective number of bits (ENOB) is a well know parameter, employed to characterize the overall behavior of an A/D converter. In order to verify if the ENOB can be also used to assess the measurement uncertainty of the A/D conversion based instruments, we use a developed software tool. The results show that using the ENOB can lead to an underestimate of the uncertainties.
Immunity of a Virtual Instrument to conducted electromagnetic disturbances
2004
In the paper the performances of the Virtual Instruments under conducted electromagnetic disturbances are investigated, in order to find out if and how their metrological characteristics change with respect to the ones measured in absence of electromagnetic threats. The analysis is carried out by means of experimental tests, subjecting the AC power port of the systems under test to the conducted disturbances considered by the IEC-61326 standard and following the test procedures prescribed in the IEC-61000-4-series standards. The results show that the tested measurements instruments are sufficiently immune to these disturbances, since no variations of the distinctive parameters have been obs…
Compact instrumentation for radiation tolerance test of flash memories in space environment
2010
Aim of this work is the description of a test equipment, designed to be integrated on board of a microsatellite, able to investigate the radiation tolerance of non-volatile memory arrays in a real flight experiment. An FPGA-based design was adopted to preserve a high flexibility degree. Besides standard Program/Read/Erase functions, additional features such as failure data screening and latch-up protection have been implemented. The instrument development phase generated, as a by-product, a non-rad-hard version of the instrument that allowed performing in-situ experiments using 60Co and 10 MeV Boron irradiation facilities on Ground. Preliminary measurement results are reported to show the i…
A virtual instrument for the measurement of IEEE Std 1459-2000 power quantities
2006
In this paper, the authors present a PC-based instrument for the measurement of electrical-power quantities defined in IEEE Std. 1459. The instrument is based on a time-domain technique for the detection of the fundamental and harmonic components of voltages and currents. The time-domain strategy was originally developed by the authors for three-phase, three-wire systems. In that paper, the strategy had been extended to both three-phase, four-wire and single-phase systems. Simulation tests were carried out to assess the uncertainty contribution of the proposed strategy in the absence of the measurement transducers. Moreover, the accuracy of the PC-based instrument with its transducers was e…
Development of a high-accuracy PC-based wattmeter with commercial data acquisition boards
2011
This paper presents the development of a high accuracy sampling wattmeter, which makes use of two commercial data acquisition boards (DAQs) connected to a common personal computer. Commercial software is also used for data processing and implementation of the virtual instrument. The set up of the PC-based wattmeter is described and a preliminary evaluation of its metrological performances is made by means of two series of experimental tests, which were carried out with an electric power standard and a high performance multifunction calibrator. © 2011 IEEE.
A PC-based wattmeter for accurate measurements in sinusoidal and distorted conditions: Setup and experimental characterization
2012
This paper presents the development of a high-accuracy sampling wattmeter, which can be employed with both sinusoidal and distorted input signals. The proposed personal computer (PC)-based system is a simple, portable, and low-cost solution because it is based on two commercial data acquisition boards connected to a common PC. Owing to this solution, the voltage is sensed directly, avoiding expensive voltage dividers, while the current is sensed by means of a noninductive current shunt. Commercial software is also used for data processing and implementation of the virtual instrument. The setup of the PC-based wattmeter is described, with a detailed description of the correction strategy of …
Virtual Instruments: Uncertainty Evaluation in the Presence of Electromagnetic Interferences
2007
The electromagnetic interferences can influence the performances of a virtual instrument; consequently, in a generic measurement performed by using these instruments, the related uncertainty values can increase. In the paper, we report the results of various experimental tests performed with the aim to check if and how the radiated and/or conducted disturbances affect the instruments' characteristics and, in particular, the single uncertainty sources. Starting from these results and applying an already proposed method for the uncertainty estimation in the measurements performed by means of virtual instruments, it is possible to take into account and to evaluate the contribute of the electro…
Reconfigurable digital instrumentation based on FPGA
2004
A novel application of FPGA to realize digital test equipment is proposed. It takes advantage of the dynamic reconfigurability of FPGAs so easily tailoring custom test functions in the same instrument. This results in high effective, compact and low cost instruments.