JOURNAL / ISSUES               ISSN 2310-6697 / ISSN-L 2310-6697
open transactions on independent scientific-engineering research


Attribution 4.0 International License CC BY 4.0
# Electrical Engineering - Théorie
Alternative Insulating Gases to SF6: A Short Review
P. -Ch. Bletsa, M. G. Danikas, R. Sarathi
The present paper undertakes the study of sulfur hexafluoride (SF6) as an insulating gas. SF6 is a modern technology gas, with the extraordinary ability to instantly "extinguish" electric arcs, thus it is mainly used in the equipment of electricity generation, transmission and distribution grid, but it can also be used in a multitude of other kinds of applications. Despite its many advantages, the use of SF6 also comes with some serious negative effects and it is important to be restricted. For instance, it is the gas that contributes the most to the "greenhouse effect" and it has a significant impact on global climate change. After the presentation of the gas and the applications in which it is used, reference is being made to the problems caused by its use and there will be a presentation of some other insulating gases that can be used as alternative solutions.
# Telecommunications Engineering - Métrologie
Measurement Uncertainty in Network Analyzers:
Differential Error Analysis of Error Models
Part 7: Remarks on the Uncertainty Notions
-from Lab VNA to Toy NanoVNA-
N. I. Yannopoulou, P. E. Zimourtopoulos
From A Common User's Point Of View [FACUPOV] any Vector Network Analyzer [VNA] -from the most expensive Laboratory VNA [Lab VNA] to an extremely cheap Do It Your Self [DIY] NanoVNA [Toy NanoVNA]- that can deliver all the values of its Calibration and the Device Under Test [DUT] in each one of the measurement frequencies, subjects to the uniquely existing estimation of its Measurement Uncertainty in that frequency, that is the one which is computed after the Exact Formation of its Complex ρ-DER Differential Error Region, as well as, of its two Real Differential Error Intervals in polar -rather than rectangular- form: ρ-magnitude DEI and ρ-phase DEI. However, due to the fast and wide spread through the Internet of a huge bunch of accompanying instructions regarding these matters, confusion has arisen from some of the concepts and notations commonly in use in VNA literature which reappears now again, as they are given obscurely, ambiguously, or even incorrectly. Accordingly, this paper presents in full details now, the work done by the authors and announced in the past during the meetings of the circle members of Automatic Network Analyser Metrology [ANAMET] technology group of National Physical Laboratory [NPL] so as to isolate among the also observed then misconceptions, those that definitely require reformulation of their expressions and perhaps a broader consensus on the range of their values and among them primarily that of phase or argument. In addition, in order to highlight the unprecedented advantages of the full and correct computation of DERs and DEIs, the following Practical Applications are included: (a) a comparison between several different in concept and form VNA quantities, (b) a counter example based on previous authors' work, (c) a 3D representation of complex ρ-DERs, and (d) a selected number of characteristic frames of AVI videos that produced by the authors to show the evolution of the 2-D outline of Complex ρ-DERs and of its two Real ρ-DEIs, both rectangular and polar, uncertainty width in terms of frequency, while the internet links to all of these videos are also provided.