Impact of fiberoptics on grounding of distributed electronics

How fiber optics is being used for proper single-point grounding of distributed electronic systems in industrial facilities with varying existing grounding approaches is outlined. Grounding schemes such as the conventional approach, single-point ground, total single-point ground, and signal reference grid are discussed. A fiber optics solution for a single-point ground system is presented. The author stresses that in all situations, grounding must be recognised first and foremost as a safety method and must adhere to the National Electrical Code     

The safety matrix-a method for guidelining industrialmicrocomputers

A matrix guideline, used to compare the safety values of existing control circuit options to those of new options, is outlined. Programmable controllers, instrument distributed control systems, front-end controllers, and microcomputers are compared to electromechanical relays to clarify the microcomputer type controllers' levels of safety responsibility. The matrix can assist those knowledgeable in safety and electromechanical relay application, but not familiar with today's microcomputer technology, in choosing the appropriate system configuration for risk-related applications     

The Microcomputer/Programmable Controller Syndrome

As the digital control field incorporates new technology (e.g., bubble memory, very large scale integration (VLSI), fiber optics, Josephsen junctions, etc.), the development of new control tools is advancing at a rapid pace. The board-level microcomputer (MC) and the programmable controller (PC) are two types of controller spinoffs from today's technology. The similarity in the architecture and functions of these units makes proper selection difficult. Guidelines for the selection of MC or PC in industrial control applications are provided.     

Programmable Controllers in Process Control Applications

The capability of the special-purpose computer called the programmable controller (PC) has been increased to the point where it has to be considered a viable alternate when selecting a controller to perform operational logic functions in chemical control applications. Guidelines used in the application of PC's in process control are described. The advent of the PC in chemical process applications provides new challenges for the manufacturer, application engineer, and user. What position in the control family hierarchy (e. g., relay sequencers, logic, microcomputers, direct digital control, mini-computers, etc.) the PC presently holds is defined.     

The Structure of the ZEBRA Telescope, the Integration Tests and the First Calibration Results

The ZEBRA telescope is a balloon borne low energy gamma ray instrument, sensitive in the photon energy range 0.2-10MeV. The main characteristics and components of the telescope are described, and its performance during laboratory calibration is discussed, after its integration with the flight electronics.     

Fiber Optic Sensors in Petrochemical Plants

Sensor technology has been affected by the advent of the semiconductor, its capability, wide range functionality, size, and cost. Today, the semiconductor industry that drives sensor design toward new concepts also is helping to create the need for fiber optic sensors in the petrochemical industry. The various fiber optic sensor technologies and their potential use in the petrochemical industry are reviewed.     

Experience with Fiber Optics in Industrial Applications

Recent fiber optic applications in industry are discussed. Application problems, user and supplier expectations, and industry's acceptance level of fiber optics is reviewed. The problems discussed reflect experience with today's mature fiber optic products. Detailed recommendations are included to help users and suppliers alike in path-forward planning in the use of fiber optics.     

Grounding and Computer Technology

Industrial grounding practices have been irrevocably altered by the advent of computer technology. Today, this grounding is further impacted by the constant evolution of computers, which is made transparent to the engineer by the advent of the microprocessor, large-scale integration, distribution, and networking. The engineering psyche involved in the grounding of today's industrial facilities is addressed. Vendor and customer concerns and goals are defined, and a structured approach to handling computer technology grounding is provided.     

Laboratory Gamma-Ray Images Using the ZEBRA Telescope

A series of approximately 100 laboratory images have been made with the ZEBRA astronomical telescope using a range of radioactive sources. These images were aimed at assessing the performance of the telescope and included combinations of point sources, extended sources, ring sources as well as vignetted sources. Besides linear reconstruction techniques a range of non linear image restoration processes are discussed.