Under pressure

March 6, 2007
Each month, CONTROL editors take a specific product area, collect all the latest, significant tools we can find, and present them here to make your job easier. This month, pressure instrumentation is the focus.

Compiled by the Editors

PRESSURE MEASUREMENTS WITH DAQ
This application note describes pressure sensors and explains how they work. It also details the requirements for measuring pressure and the signal conditioning required for the measurement. It also explains how to use NI DAQ systems to measure bridge-based sensors, and recommends three different starter kits for pressure measurement. Finally, an appendix is included explaining less common pressure sensors and their areas of application. National Instruments; 888/280-7645;

METHODS OF MEASURING PRESSURE
Web site gives users the pros and cons of different devices used for pressure measurement and control. It contains diagrams of U tubes, Bourdon tubes, diaphragm theory and McLeod theory. For instance, the information relates that diaphragm pressure gauges have a much faster frequency response than U tubes; however, they are more expensive than other pressure sensors. Efunda; 800/398-5968; www.efunda.com/designstandards/sensors/bourdon_tubes/bourdon_intro.cfm

TESTING HYSTERESIS OF PRESSURE SENSORS
Application note discusses validating hysteresis of pressure switches on pipeline pigging systems. An integral part of the pigging system is a pressure switch which, unless energized, will not allow the pig to operate. Application note offers examples of how to correct the situation and eliminate shutdown of the system. GE Sensing; 800/833-9438; www.gesensing.com/druckproducts

GLOBAL MARKETS FOR PRESSURE TRANSMITTERS
This white paper presents the global markets for electronic pressure transmitters, transducers and component-level sensors. The study findings are contained in three volumes, one each for electronic process pressure transmitters, electronic non-process pressure transmitters and transducers and electronic component-level pressure sensors. The combined global market of these products exceeded $US 4 billion in 2005. Venture Development Corp; 508/653-9000;  www.vdc-corp.com

CHALLENGES TO MEASURING PRESSURE
This article written by Brian Link at Honeywell Aerospace Electronic Systems, Plymouth, Minn., is called “Measuring Pressure with Precision Can Be a Challenging Job. Transducers Provide the Accuracy Required.” It discusses what makes sensors smart, digital alternatives, programmable design options and more. Honeywell Solid State Electronics Center; 800/323-8295; www.pressuresensing.com 

INS AND OUTS OF I/P TRANSDUCERS
This white paper, found in the white paper library on ControlGlobal.com, discusses the ins and outs of I/P transducers. I/P transducers are relatively simple devices, but there are numerous factors to take into account before selecting one. The paper provides complete understanding of the factors involved in making the correct product selection, installation and maintenance. ControlAir;  www.controlglobal.com/whitepapers/2006/057.html

RoHS COMPLIANCE FOR PRESSURE INSTRUMENTATION
This web site gives detailed information on RoHS compliance. RoHS stands for the European Union’s directive 2002/95/EC on the restriction of use of certain hazardous substances in electric and electronic equipment. The directive applies to products sold for use in the European Union. The site lists RoHS-restricted materials, including those products using pressure instrumentation, that are covered by the directive. IDES; 800/788-4668; www.ides.com

PRESSURE INSTRUMENTATION  SOURCES
EngNet engineering network is an online resource for engineering products and services of all kinds. It lists suppliers of all sorts of pressure instrumentation and measuring devices—indicators, switches, gauges, transmitters, transducers and instrinscially safe calibrators and measuring instruments. EngNet Engineering Network; www.engnetglobal.com/p/p.aspx/Ins/pre01