Techweb - The Instrument, Control, Electrical, Fire and Gas and Safety Instrumented Systems Engineers Technical Resource
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Accelerometers - Technical papers about measuring vibration, shock or pressure plus AC and DC signal conditioning equipment - you will have to log on but it will be worth the effort (From Endevco).
Acronyms for Engineers - A comprehensive list of some 900+ of those "dreaded" acronyms.
Acronyms - from Ireland's great readout magazine.
Analysers - ICEweb's comprehensive page.
Analyser Sample Systems - ICEweb's comprehensive page.
Australian Standards - See Standards
Bursting Disks - a full page of links
Burner Management Systems - ICEweb's comprehensive page.
Cables-IEEE 1242 Specifying and Selecting Cable for Petrochemical Plants a Guide - By Donald A Voltz and Joseph H Snow, this is a really excellent technical paper from Mustang Engineering.
Cables - Best Practices for Process Instrumentation Cabling - Connectivity glues the network together; Cabling, grounding, cable routing, and the mitigation of noise and interference - Saeed M. AL-Abeediah - The health and effectiveness of any plant’s Process Automation System (PAS) relies on many factors. Among these factors is the proper selection of PAS components, seamless integration, control schemes, control system installation, and last but not least, proper electrical installation and connectivity of field instrumentation devices. This last factor, which glues the entire PAS system together, involves cabling, grounding, cable routing, and mitigation of external influences such as noise and interference. Thanks to the ISA and InTech.
Cable Glands Why Should You Specify Cable Glands? - How often have we heard:- "We don't specify Cable Glands, as long as they have the relevant certification then it must be fit for purpose. We leave it to contractor to sort out. We are too busy concentrating on the high value, long lead time items to bother about such an insignificant value product. In a recent paper presented at the Hazard Ex conference by a Senior Manager of CENELEC Standards Inspections, it was stated, "Resources should be directed at eliminating the following common faults; Unauthorised modifications, badly made-off or unsuitable cable entry devices and Corrosion. It went on to say that out of these three factors, the most common fault was bad installation of Cable Glands. The paper was specifically referring to maintenance procedures, but this could equally be applied to new installations. Incorrect specification and installation combined with the lack of ability to inspect the Cable Gland in it's operable condition can cause equipment failure and corrosion of cable armour and braid. The safety risks inherent in this is incalculable, as is the consequential loss of production.This statement alone should be enough reason why specification of Cable Glands is an important decision. Just relying on the fact that a Cable Gland has a certificate "fit for purpose" is not enough - from Hawke International.
Calculator - A super calculator for when you don't have one available.
Calculators and Conversions - Martindale's Reference Desk Calculators On-Line Center site has the lot...a little complex in its navigation however.
Calibration and Testing - ICEweb dedicated page full of information on calibration and Testing thanks to Zedflo Australia.
Choke Valves - ICEweb's comprehensive page.
Classification of Hazardous Areas Technical Information page - including design, classification, installation and maintenance information.
Condition and Machine Monitoring - ICEweb's comprehensive page.
Common Fluropolymer Comparison Chart - (Supplied by Swagelok).
Communication in the Field - from Samson Controls.
Communication Networks - from Samson Controls.
Constants - (National Institute of Standards and Technology).
Control - ICEweb's comprehensive page - Process Control Engineering is a complex discipline as it covers a vast range of different Control Related Technical Subjects. This page includes Advanced Process Control and Optimisation, Alarm Management, Batch Control, Cascade Control, Compressor Surge Control, Control Room Design, Control Systems, Decentralised Control, Fuzzy Logic, Legacy Process Control Systems, ModBus, Loop Tuning, Pneumatic Controllers, Process Sequence Control Documentation Standards, Programmable Automation Controllers, Modelling and Optimisation, Process Control Security, Process Control System Ergonomics, Proportional, Integral and Derivative Control, OPC - OLE for Process Control, it also provides links to useful Control System Forums and much more!
Control Engineering Terminology and Symbols (Samson Controls Pty Ltd) - Planning, design and start-up of process control systems require clear and unambiguous communication between all parts involved. To ensure this, we need a clear definition of the terms used and . as far as the documentation is concerned . standardized graphical symbols. These symbols help us represent control systems or measurement and control tasks as well as their device-related solution in a simple and clear manner.
Control Valves - ICEweb's Comprehensive Control Valve Technical Information Page covers Selection and Design, Cavitation and Flashing in Control Valves, Control Valve Actuators, Butterfly Control Valves, Control Valve Sizing, Split Range Control Valves, Control Valve Applications, Control Valve Noise Calculation and Prediction, Control Valve Maintenance, Control Valve Positioners and Self Operated Regulators.
Conversions - from joshmadison.com.
Conversions - Megaconverter makes it easy.
Corrosion - Look at ICEweb's Corrosion Page for links to loads of information.
Cylinder- Air Consumption calculations - (From Cole Parmer).
Data Loggers - Data Loggers are very useful instruments which record and monitor instrument measurements over a defined time frame. They have many applications across a broad spectrum of industry.For Control Systems they can be utilised for Sequence of Event applications. A data logger collects the measurement information over a continuous period on a 24hr, & day basis depending on the onboard memory. Thus they can provide accurate reliable information of the measurements that are required to be monitored.
Digital Signals - (Samson Controls Pty Ltd) PDF Format.
Electrical Test and Measurement Equipment - Electrical Test and Measurement Equipment is an essential part of any Electrician's tool kit. With today's technological advances high quality electrical test and measurement tools are required. By purchasing highly specified equipment one can be assured of safety, accuracy and robustness along with user interfaces which make them more user friendly. The equipment is used to test and verify safety and operating parameters of Electrical Equipment. Typical Electrical Test and Measurement Equipment tests Insulation resistance, Continuity of protective conductors and equipotential bonding, Residual Current Devices , Line Impedance, Fault Loop Impedance, Earth Resistance, Phase Sequence, Voltage and Frequency, PE Test Terminal, Overvoltage Category, HV, Step / Contact Voltage and Earth Resistance.
Electrical Theorems and Formulae for Students and Engineers - (An excellent site from BOWEST PTY Ltd - A fellow West Australian Company).
Electrical Information - from Valhalla Scientific - Includes Fundamentals of Power Measurement, Power related Topics and Parameters, Motor and Generator application notes, Transformer application notes and Benefits of power analysis on product reliability.
Electrical Information - Including Cenelec and IEC hazardous Area Information, North American Hazardous locations, IP code information and Abbreviations, Acronyms and Definitions - From Hawke International.
Electrical - The Differences between Watts and Volt Amps - Steve Mackay - I often get questions about the practical differences between watts (W) and volt-amperes (VA); mainly from our civil and mechanical engineering fraternity; but surprisingly also from some electrical types. As you would know, electrical products generally indicate both to show how much energy and current they draw. This Blog details a quick summary of the differences with some interesting alternative calculations to work out total VA.
Electrical Lighting - How much does it cost you to change a light globe? - Do you want to dramatically reduce your lighting maintenance costs and reduce your risk hazards? Lighting maintenance is a necessity and often an expensive job in the industrial work place today. The costs involved are usually high due to the positioning of light fittings. This no longer needs to be the case. The installation of an In2 Light Hatch® will dramatically reduce the costs involved in changing light globes on industrial work sites.
Electrical Engineering - ICEwebs Electrical pages.
Exd Immersion heaters - Over the years it has been difficult to source Exd Certified immersion heaters and often this has led to a certification nightmare for those engineers responsible for the associated equipment packages. These IEC certified heaters may provide the solution
Ex Hazardous Area Technical Information page - including design, classification, installation and maintenance information. Loads of great technical information here.
Electronics Basics - (ePanorama.net).
Electronic /Electrical terms and definitions - Looking for an electronic or electrical term and its definition? Electropedia is the world's leading online electrical and electronic database containing more than 20 000 terms and definitions in English and French organized by subject area, with equivalent terms in German and Spanish. This is a terrific resource thanks to the IEC.
Electrical and Instrumentation Enclosures - ICEweb's page covering NEMA and IP ratings, Design Guidance Standards and more.
Fibre Optic Cables - The Basics - An excellent tutorial from ARC Electronics.
ICEweb's Fieldbus Pages:
- Foundation Fieldbus - Foundation technology is the world's leading digital protocol for process automation. It provides end users with the "Freedom to Choose" best-in-class, interoperable control products from their suppliers of choice, and the "Power to Integrate" control systems, subsystems and devices across the plant enterprise. The result is improved plant performance-and greater business results.
- CANopen - CANopen is a CAN-based higher layer protocol. It was developed as a standardized embedded network with highly flexible configuration capabilities. CANopen was designed for motion-oriented machine control networks, such as handling systems. By now it is used in many various fields, such as medical equipment, off-road vehicles, maritime electronics, public transportation, building automation, etc.
- HART - The HART Protocol was developed in the mid-1980s by Rosemount Inc. for use with a range of smart measuring instruments. Originally proprietary, the protocol was soon published for free use by anyone, and in 1990 the HART User Group was formed. In 1993, the registered trademark and all rights in the protocol were transferred to the HART Communication Foundation (HCF). The protocol remains open and free for all to use without royalties. This technical section focuses on providing information that is relevant to the various aspects of the HART Protocol. We will discuss what it is, how it works, and the benefits of using the HART Protocol.
- Industrial Ethernet
Industrial Ethernet offers significant advantages including;
- Integrated communication from the machine to the office
- No gateways required at transition from field level to office
- Remote diagnostics and monitoring through Internet connection
- Advantageous assignment of stations using virtual private networks (VPNs)
- MODBUS - MODBUS is the most popular industrial protocol being used today, for good reasons. It is simple, inexpensive, universal and easy to use. Even though MODBUS has been around for nearly 30 years, almost all major industrial instrumentation and automation equipment vendors continue to support it in new products.
- Profibus - Utilizing a single, standardized, application-independent communication protocol, PROFIBUS supports fieldbus solutions both in factory and process automation as well as in motion control and safety-related tasks.
Flow - This comprehensive ICEweb page provides Engineering Information on Coriolis, Metering, Multiphase, Orifice Plates, Ultrasonic, Thermal, V-Cone, Vortex and more.
Fire & Blast Information Group - (FABIG).
ICEweb's Comprehensive Fire Detection Page - Links on CCTV Techniques, Detector Selection, Fire and Flame Detection, Fire Detector Maintenance, Fire Systems Integrity Assurance, Eliminating False Fire Alarms, Oil Mist Detectors, Smoke Detectors and Lots More!
Fire Detection and Emergency Warning Systems in Buildings - (Supplied by Ampac industries Pty Ltd).
ICEweb's Fire Protection Page - Covers Fire Protection including Carbon Dioxide, Water Mist, Inergen and More!
Fire Safe Actuators - from Samson Controls.
Fittings - ICEweb’s comprehensive technical papers and other engineering information on Instrument Fittings.
Fittings - 10,000 PSI Fittings Specification - (Supplied by Prochem).
Fittings - NPT thread Tolerances - (Supplied by Swagelok-www.swagelok.com).
Flare Pilot System Safety - John Bellovich, Jim Franklin, and Bob Schwartz - One of the worst nightmares a plant manager can experience is a complete flare system outage. The flare system is the last line of defense for many refining and petrochemical facilities and, when out of commission, can cause the shutdown of the entire facility. Flare ignition failure may lead to unburned venting of dangerous gases, and may develop into an explosive hazard leading to the loss of property and equipment, or worse, injury to personnel or loss of life. The safety and effectiveness of flaring are dependent upon one or more continuously burning pilots for immediate and sustained ignition of gases exiting a flare burner. Because pilot failure can compromise safety and effectiveness, it should be detected quickly and accurately to allow prompt automatic and/or operator response. Proper disposal of process and waste gases during routine and/or emergency conditions is crucial to help operating facilities protect plant employees and the surrounding community, and to avoid hundreds of thousands of dollars in fines. These reasons alone make the pilot monitoring and ignition system the most important component of any flare system. The advanced flare pilot systems explained in this article offer increased protection from harsh environmental conditions and rapid notice of pilot flame failure. Recently published in dustry standards for flare pilot design and performance are also discussed - from John Zinc Company.
Install Electronic Flare Ignition Devices - This technology replaces the intermittently or continuously burning flare pilots with electrical sparking pilots similar to a modern gas stove. These sparking pilots require low electrical power that can be supplied from a battery with solar recharge in remote sites. In addition to using electronic flare ignition devices for pilots, facilities may also install sensors to detect the pilot sensors to detect the pilot flame and shut off fuel gas if the pilot is extinguished - from EPA.
Flare Ignition Systems - With the developments in chemistry and petrochemistry on one hand, and concern for the environment on the other, more and more requirements are being set for the emission of flaring systems. Flaring systems have undergone considerable development, from a pipe with a perpetual flame to a well thought-out combustion system with pilot flame burners, purge gas, steam injection and automatic ignition. Go to page 3 for principles - from Smitsvonk Holland BV.
Flame and Gas Detection Handbook - Ampac Industries Pty Ltd.
Flow and Level Calibration Information Notes - (INX Inc).
The following articles are kindly provided by Andy Jamieson;
- New Developments in Metering Technology
- Recent Experience on Implementation of New Techniques of Gas Metering
- Multiphase Metering - The Challenge of Implementation
- High-performance Multiphase Metering - A Personal Perspective
Flowmeters, Liquid - (Omega.com).
Flow Measurement information Notes - (INX Inc).
Flow-Water Measurement Manual - (US Government Water Resource Research Laboratory).
Fluid Fundamentals - (Cole Parmer).
Foundation Fieldbus - Samson Controls.
Fuzzy Logic - All you wish to know on this ICEweb page.
Gas Detection - This incredibly useful Engineering Technical Information resource from ICEweb covers about Gas Detection.
ICEweb's Comprehensive HART Communications Protocol Page.
HART Communications - Samson Controls.
Reading HART Data into Non-HART Systems - Many HART products are able to perform more than one measurement or output function (e.g., make multiple process measurements, calculate process information, and provide positioner feedback information). All of this information can be easily accessed digitally. However, existing controllers or interface equipment may not have the ability to read digital HART data. Products are available that can read HART digital signals and convert them to analog (4-20mA) and alarm trip (contact closure) information, which enables any traditional analog control system to take full advantage of the benefits of HART- communicating devices. From Moore Industries-Pacific, Inc.
Hazardous Area Technical Information page - including Design, Classification, Installation and Maintenance Information.
Heat Tracing and Bundles - This ICEweb page Covers Heated Hose, General theory and associated Applications.
High Integrity Pipeline Protection Systems (HIPPS) - HIPPS Systems reduce the need for traditional mechanical relief devices and the level of flaring in oil and gas applications. New installations can use the benefits to minimise the requirement for pressure relief valve manifolds and flare systems. On existing processing plants HIPPS Systems may eliminate the need to upsize the flare and the relief valve manifold as a result of increased throughput and in some cases actually provide the technology to remove an existing system. Installing a HIPPS system at the wellhead or pressure source allows the downstream piping to be down rated and as a result reduce capital expenditure. On offshore installations flaring can be significantly reduced and on new installations, significant weight savings may be attained with the use of HIPPS.
Humidity Analysers - Product quality improvement with correct moisture measurement in thermal processes using electrolytic hygrometers. From Able Instruments.
Humidity - Theory and Information of Condensation Chilled Mirror Hygrometers (some good humidity definitions) - From Able Instruments.
Humidity Sensors for Industrial Applications - From Able Instruments.
Hydaulic Instrumentation - This ICEweb page provides engineering information on this complex subject.
ICEweb's Instrument Signal Conditioners, Transmitters, Transducers, Isolators and Converters page is just full of information on these subjects.
Infra-red Open Path (line of sight) Gas Detection - ICEweb has a Technical Information Page for Instrument and Fire & Gas Engineers dedicated to Open Path Gas Detectors, it covers Infra Red Line of Sight (Open Path) and Point Detectors Principle of Operation, Technology, Calibration and more!
Instrument Air Receivers - Warning on Air Receivers - WorkSafe Victoria has released new guidance focussing on the safety risks associated with air receivers - a type of pressure vessel used to store compressed air for large demands greater than a compressor's capacity. WorkSafe director Ross Pilkington says air receivers have the potential to seriously hurt people and damage property if they were not properly installed or maintained. There have been serious incidents involving air receivers exploding in Victorian workplaces - and it has only been good luck that no one was working near them at the time. Employers with air receivers must ensure they are properly maintained to reduce the risk of explosion or fire. The handbook 'Working safely with air receivers' is aimed at improving awareness of the risks associated with air receivers, and explaining ways to eliminate and reduce those risks.
Instrument Tubing - Heaps of great technical information from ICEweb.
Instrumentation Terminology - Glossary of Terms - from Instrumentation World.
Instrumentation, Control, Fire & Gas and SIS Design Engineering - ICEweb’s very popular comprehensive page on this subject.
Instrument and Control Technical Information - Some great information on individual topics about the basics of control engineering, self-operated regulators, control valves, communication as well as building and process automation - from Samson Controls.
Instrumentation, Control, Fire & Gas and SIS Design Engineering Software Database - Today, on small and large projects an Instrument Design Software tool is an essential part of completion of the design documentation. There are several companies which have developed these systems.
IP Ratings and NEMA
ICEweb has a comprehensive Level Page just full of technical information.
Lightning and Surge Protection Page - Lots of technical information links on this fascinating subject.
Monoflanges and Instrument Manifolds - Technical Engineering information on these time, cost and space saving Instrument Hookup accessories.
Manufacturing and Automation Safety - A full page of Technical information.
Fibre Optic Sensors for Measurement of Flow, Level, Pressure, Stain, Temperature and Vibration - from Davison Instruments.
A Beginner’s Guide to Measurement - This 30 page Beginner’s Guide from the National Physical Laboratory explains the fundamental concepts and basic facts about measurement, and in particular accurate measurement. It includes brief accounts of the role of measurement in modern and historical societies and explains the SI system, its base units and their relation to other units. The various organisations involved in measurement are introduced and their roles in linking all measurements to the SI base units through traceability chains explained. It includes general guidance about practical issues that affect the making of measurements, gives the meanings of key measurement terms, and explains the significance of such fundamental concepts as measurement traceability and calibration.
Metric Units - Frank Tapson - This provides a summary of most of the units of measurement to be found in use around the world today (and a few of historical interest), together with the appropriate conversion factors needed to change them into a 'standard' unit of the SI - from the Rensselaer Polytechnic Institute.
See IP Ratings and NEMA.
NPT Thread Tolerances - thanks to Engineers Edge.
Ohms Law - from the Electronics Club.
Ohm's Law, Online Calculator - from Ohm's Law Calculator.
Oil in Water Analysers - The need for an in-line oil-in-water monitor - kindly provided by Andy Jamieson.
OPC Foundation - (OPC Foundation)
pH Measurement and Instrumentation - ICEweb’s comprehensive page on this subject.
PLCs - (Personal PLC Tutor).
Power Meter- Get to know your Power Meter - What is Real, Apblank and Reactive Power - This useful article from chipkin.com discusses some of the traps to avoid.
Preliminary Engineering - (INX Inc).
Pressure Unit Conversion - Look up conversion factors or select a conversion table for a particular pressure unit.
Pressure Measurement Information Notes - (INX Inc).
Pressure Measurement and Instrumentation - This ICEweb page contains comprehensive Pressure Technical Information and covers theory, safety tips, pressure conversions, pressure measurement and instrumentation, pressure transmitters/sensors, differential pressure and lots more!
Pressure - Relationship with elevation - Cole Parmer.
Pressure Terms - Cole Parmer.
ICEweb's Pressure Relief Valves Page - This is a comprehensive page with links to a huge vault of Pressure Relief Valve Information.
PROFIBUS-PA - Samson Controls.
Pump Curve- Ever needed to know how to read a curve? - Cole Parmer.
Pumps - Lots of Information from Cole Parmer.
Guide to Low Resistance Measurement - Understanding and Measuring Low Resistance to Ensure Electrical System Performance. The purpose of this booklet is to help the engineer, technician or operator:
- Understand the rationale behind low resistance testing.
- Understand how to make a low resistance measurement.
- Understand how to select the proper instrument for the testing application.
- Understand how to interpret and use the results.
Resistors - Beer and Vodka can help you Select a Terminating Resistor - Covers Resistor Colour Codes, How to buy resistors, How to make a resistance value even if you don't have the correct resistor in your toolbox and Resistor colour codes for 4 and 5 band resistors - from chipkin.com.
Resistor Colour Codes - from Ohms Law Calculator.
Resistor Colour Code Calculator - This calculator displays the value, the tolerance and performs a simple check to verify if the calculated resistance matches one of the EIA standard values - from Hobby-Hour.com.
Rupture Disks - a full page of links.
RS485 on a Scope Using an Oscilloscope on a RS485 Network - For reference purposes here are some scope captures of a typical RS485 line - from chipkin.com.
Safety Instrumented Systems (SIS) - Instrumented Protective Functions and Emergency Shutdown (ESD) and Process Shutdown (PSD) Systems - This ICEweb Engineering resource is just massive and attracts over 300 Engineers a month.
Safety Relief Valves - a full page of links.
SDV/BDV/ESD Valves - This very popular ICEweb page includes engineering information on Selection, Partial Stroking, Firesafe Actuators, Technical Papers and more!
Security - ICEweb's Control System Security page has many technical articles and white papers on this subject.
Cutting Costs using Self-operated Regulators - Mr Wolfgang Hesse - At the beginning of the last century, the first self-operated regulators were used for simple control tasks which marked the beginning of process automation. Nowadays, many of us are not aware of the advantages, the design, the principle of operation as well as the limits of this type of technology. In this paper, Samson's Mr Wolfgang Hesse outlines how cost effective self-operated regulators can be.
Sensors - The basics - A terrific resource from Cutler Hammer.
Serial Data Transmission - from Samson Controls.
Severe Service Valves - This ICEweb Page includes some great technical information from Mokveld along with some other technical specs etc.
Signal Conditioners, Transmitters, Transducers, Isolators and Converters - Another ICEweb page with everything that you need to know on this subject.
Signals - A look at 4 - 20 Milliamp Signals - Arthur Holland, Holland Technical Skills - A good description of 4-20Ma technology - Thanks to Eurotherm.
Signal Isolators, Converters and Interfaces: The "Ins" and "Outs" - Parts 1 and 2.This primer details how to select and use the correct signal isolator in the correct way to optimize your process. Learn about selecting isolators that share, split, boost, protect, step down, linearize and even digitize process signals - from Moore Industries-Pacific, Inc.
SI Units - from NIST.
ICEweb's Surge Protection Page - Lots of technical information links on this fascinating subject.
Standards - Current Australian Hazardous Standards.
Switches - Some excellent technical information from Omron.
ICEweb's Temperature Instruments and Measurement Page - This comprehensive Technical Information page covers; Basics of Temperature Measurement, Temperature Conversion, Bi-Metallic Principals, Emissivity, Mercury in Steel, Temperature Standards, Selection of a Temperature Transmitter/Sensor, Temperature Sensor Types / Uses / Measurements / Applications, Resistance Thermometers, Radiation/IR Thermometers/Pyrometers (Non Contact Temperature Measurement), Thermocouples, Thermistors, Thermometers, Thermal Imagery, Thermowells, Temperature Scales and Conversions, Temperature Regulators and Temperature Sensor Calibration Resources.
Temperature Measurement Calibration Notes - (INX Inc).
Temperature Measurement Information Notes - (INX Inc).
Temperature Regulators - (Samson Controls Pty Ltd) PDF Format.
Overview of Temperature Sensors - You can choose from a variety of sensors to translate temperature phenomena into a measurable signal. Three common sensor varieties are the thermocouple, RTD, and thermistor. Each has its own operating principles, benefits, considerations, and drawbacks. This document provides context and information to help you select the best temperature sensor for your application needs - from National Instruments.
Temperature - Traps and Colour Confusion in Thermocouple Wiring - This article concerns inaccuracies and instabilities caused by misuse of thermocouple extension cable on temperature control systems. The jungle of different cable colour codes is a major source of such problems. - (Thanks to Arthur Holland, Holland Technical Skills, Oakville, Canada).
Test and Calibration Instrumentation - This ICEweb page details why Instrument Calibration must be carried out to maintain and verify instrument accuracy along with much more about the subject. It covers Test and Calibration Instrumentation, Calibration Forms, Calibration Principles, Calibration Terminology, Calibrating Fieldbus Instruments, Calibration Frequency, Calibration Advantages using Electronic Device Description Language (EDDL) Technology, Other General Test and Calibration Links, Electrical Measurement Safety, Test and Calibration Standards, Temperature Instrument Calibration and Useful Books on Instrument Calibration and Measurement.
Tubing and Fitting Standards - ICEweb's very useful resource for anyone looking for Instrument Fittings and Tubing.
Controller Tuning - ICEweb's Process Control Systems Page has numerous technical papers and tutorials on this subject.
Two Wire Transmitter and the 4 - 20mA Current Loop - First appearing in the 1950’s with the advent of electrical and electronic controls, the 4-20mA signal standard reigns as one of the most popular mediums for signal transmission and electronic control in industrial environments nearly 60 years later - from www.automation.com and Acromag.
Imperial Units - tables and conversions.
Imperial Units - With modern man now using the metric system there is sometimes a need to remember what the old units of measurement were, the common and not so common.
Uncertainty, Units - National Institute of Standards and Technology.
Introduction to Valves - By definition, valves are mechanical devices specifically designed to direct, start, stop, mix, or regulate the flow, pressure, or temperature of a process fluid. Valves can be designed to handle either liquid or gas applications. By nature of their design, function, and application, valves come in a wide variety of styles, sizes, and pressure classes. The smallest industrial valves can weigh as little as 1 lb (0.45 kg) and fit comfortably in the human hand, while the largest can weigh up to 10 tons (9070 kg) and extend in height to over 24 ft (6.1 m). Industrial process valves can be used in pipeline sizes from 0.5 in [nominal diameter (DN) 15] to beyond 48 in (DN 1200), although over 90 percent of the valves used in process systems are installed in piping that is 4 in (DN 100) and smaller in size. Valves can be used in pressures from vacuum to over 13,000 psi (897 bar). An example of how process valves can vary in size is shown in Fig. 1.1. Today’s spectrum of available valves extends from simple water faucets to control valves equipped with microprocessors, which provide single-loop control of the process. The most common types in use today are gate, plug, ball, butterfly, check, pressure-relief, and globe valves. Valves can be manufactured from a number of materials, with most valves made from steel, iron, plastic, brass, bronze, or a number of special alloys - from mhprofessional.com.
Wireless Instruments and Instrumentation - This is a rapidly developing area of instrumentation which results in substantial cost savings.