This paper presents the results of tests conducted on ways of reducing the four types of noise encountered in electronic instrument circuits.
The use of computers and other sensitive electronic equipment in process instrumentation systems has demanded that more attention be give to electrical noise pickup in instrument circuits.
The superior performance of aluminum-Mylar tape shields in comparison with copper braid and copper served wire shields for static noise rejection is described.
The effect of twisting wires to cancel magnetic noise is compared to various shielding materials. Twisting the wires is shown to be the most effective practical way of reducing magnetic noise.
The control of common mode noise by the proper grounding of shields in thermocouple circuits is shown. The use of single grounding points in shield circuits grounded at the couple is recommended. Multipair cables with individual isolated pair shields are recommended.
Comparative results on cross talk elimination in multipair cables are presented. Individually shielded pairs are recommended as the most practical means of cross talk rejection in instrument circuits.
Dekoron Division, Samuel Moore & Company. Bruce E. Klipec
Since 1994, PAS has benchmarked hundreds of alarm systems in various industrial markets around the world. From our project databases, this paper presents examples of the worst, most overloaded alarm systems encountered. In addition, the possible solutions to these problems are discussed.
This paper summarizes key aspects of WirelessHART, including several of the design decisions that make it the right choice for wireless process automation. More detailed information is available at www.hartcomm.org.
This whitepaper, written by Vince Marchant, a senior application engineer at Moore Industries, describes how Modbus works, and how it can be used in new and legacy process control and automation systems.
This article will explore the use of a wireless diagnostic OLE for Process Control (OPC) server technology to embed diagnostic information in human machine interfaces (HMIs), thus optimizing industrial wireless network performance.
This white paper explores fuzzy logic and how it helps engineers solve nonlinear control problems commonly found in process applications. Fuzzy logic, which mathematically emulates human reasoning, provides an intuitive way to design function blocks for intelligent control systems, advanced fault detection and other complex applications. Control systems deploying fuzzy logic can improve the management of uncertain variables, such as temperature fluctuations.
Nearly every product, service, application and data type is moving to an IP-based infrastructure. As a result, formerly isolated products in homogenous networks are embedded within heterogeneous deployments, resulting in dramatically larger and more complex attack surfaces that are exposed to a wide variety of potential attack sources.
Manufacturers of level measurement technologies are often asked to recommend a technology for measuring bulk solids in vessels. Understanding the technologies available is an advantage when searching for an answer to the question of what to do.
The objective of this white paper is to educate the reader on the selection of point level monitoring technologies for specific applications to improve process efficiency, reduce up-front costs and minimize overall cost of ownership.
The Mu-4000 Security Analyzer has emerged to help QA integrate optimized negative testing without impacting productivity. It delivers metrics related to service availability and security, resulting in the vendor knowing it is shipping higher quality products.