A novel frequency computation technique suitable for single or three phase voltage signals is proposed. The method is based on a generalization of the zero crossing detection to a level crossing detection. This yields several estimates of the frequency within one cycle. A composite "best estimatet" is obtained by an appropriate weighted average of these estimates. The method is insensitive to amplitude variations, unbalance and is capable of tracking small frequency deviations in as short a duration as a fraction of a cycle. The measurement scheme is particularily suitable for integration with the digital schemes for real-time monitoring control and protection of power systems.

A New Technique for Rapid Tracking of Frequency Deviations Based on Level Crossings

A bewildering variety of documents is classified under the general heading of reports. The method of presentation may be a pre-designed form,* a letter, a memorandum or a book. The length may vary from brief notes, or even figures, filled in on a standard form, to hundreds of pages in several volumes.

Reports and Memoranda

In this paper, an attempt has been made to design a low-cost noncontact capacitance-type level sensor for a conducting liquid. The sensor is in the form of a uniform circular cylinder made of insulating material like glass, ceramic, plastic, etc. The sensor is connected with the metallic- or nonmetallic-type liquid storage tank, in which the conducting liquid column is taken as one electrode, and a noninductively wound short-circuited outside coil is taken as the other electrode of a variable capacitor. The change in capacitance due to the change of liquid level is measured by a modified linear operational-amplifier-based De' Sauty bridge network with adjustable bridge sensitivity. The bridge output after amplification and rectification may be used to drive a direct current indicator calibrated in level. The studies have been made with high-density polyethylene and glass tube sensors separately in both metallic and nonmetallic storage tanks with tap water as the conducting liquid, and the experimental results of the static characteristics of the level sensors with percentage error from linearity are presented in the paper. These results are found to have good linearity and repeatability within acceptable limits

A low-cost noncontact capacitance-type level transducer for a conducting liquid

Present work deals with the development of a low cost moisture sensor for measuring moisture in the range of 2.5–25 ppm using nanoporous thin film of alumina (γ-Al 2 O 3 ). Thin film of γ-Al 2 O 3 prepared by low cost and simple sol–gel method offers very high surface to volume ratio with distribution of micro pores for moisture detection. Pore morphologies of the film have been studied by FESEM, AFM, XRD and BET methods. To form a capacitive sensor, the porous film of 3–6 μm thickness was dip-coated in between two parallel gold electrodes. The characteristic of the sensors have been examined by Agilent 4294 A impedance analyzer for the frequency range of 1–20 kHz. The characteristics of the sensor can be used for making trace moisture sensor for commercial applications. The capacitance change with moisture is almost linear with 1.05% nonlinearity and 0.33% hysteresis.

A novel sol–gel thin film porous alumina based capacitive sensor for measuring trace moisture in the range of 2.5–25 ppm

A course on the emerging topic “Smart Sensors and Internet of Things (IoT)” has been designed, developed, and delivered from 21st March 2016 to 31st March 2016 in the Department of Electrical Engineering, Jamia Millia Islamia (Central University), New Delhi-110025, India. This course was organized under a program initiated by the Government of India, entitled “Global Initiative of Academic Networks” for higher education. The basic objective is to bring the internationally and nationally acclaimed scientists on a single platform to motivate young minds of India so that India’s scientific and technological capacity reach global excellence. The course was designed to develop the technical skills for the students, the researchers, the engineers, and the faculties, who desire to address some of the issues faced by the people around the world in the fields of smart sensors and IoTs with applications in smart homes, smart cities, smart grids, smart environment, smart transport, and so on. The assessment of the course by the participants shows extreme usefulness of it.

Smart Sensors and Internet of Things: A Postgraduate Paper

Electrical measurements and measuring instruments , Electrical measurements and measuring instruments , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی

E. W. Golding

Papers

Electrical measurements and measuring instruments