Field Instrumentation Resource Center
Flowmeter Technology Library
Measurement of those key elements of process control—temperature, pressure, flow and level—are essential. Getting that information smoothly, quickly, accurately and securely from field instruments is an essential part of any process operation. The Field Instrumentation Resource Center provides you with the information you need—articles, white papers, news reports and product announcements—to keep you up to date on calibration, measurement, testing, fieldbus standards, wired and wireless instrumentation, and all the other information you need.
The Latest in Level
Level Sensors, Transmitters, Switches and More
The Engineering Screw Chart
Engineers, Designers, Drafters and Machinists should all have access to the Engineering Screw Chart. It includes technical information from many of the quick references that are commonly found in the work areas of industry professionals. All of this information is compiled for both Imperial (English) and Metric systems in a single screw cart. Watch this video to learn more.
Motors and Drives Grow Up and Graduate
Motors and Drives Have Been Moving Up to Variable-Speed Control for Better Accuracy, but Now They're Also Increasing Power Density and Efficiency and Even Coordinating More Closely With PLCs and Intelligent Systems
Relief Valve Blowdown Rings; D/P and Straight Runs
Readers Ask: When It Comes to Safety Relief Valves, What Is Best? Using Two Blowdown Rings or Ones? and Can a Transmitter Be Installed Above Pipe Taps?
White Papers: In Depth Research
Weigh Your Instrumentation Options: Switch, Transmitter or Hybrid?
For decades, process instrumentation specifiers have faced the decision whether to use a mechanical switch or a continuous transmitter for a given application. Either type of instrument can be used to effectively control industrial processes and protect equipment and personnel -- and each has associated pros and cons. Application specifics typically drive decision-making, dictating which approach is most effective from performance, cost and lifecycle support perspectives.
At its most basic, a switch acts in a binary fashion, changing state when a pressure, temperature, level or other process variable crosses over some predefined threshold. If the process variable in question can be allowed to vary in the course of normal operation, a simple mechanical switch linked to an on/off valve or pump can effectively and reliably control the process at hand, keeping a tank from running dry or a temperature from climbing too high.
Transmitters, on the other hand, continuously measure and communicate their assigned process variables over a range of values. A transmitter can facilitate on/off control actions similar to those of a switch through configurable discrete outputs within an associated controller. But a continuous transmitter teamed with a modulating control valve or pump with variable speed drive also can be used to implement more subtle (albeit more expensive) control strategies -- such as a proportional‐integral‐derivative (PID) algorithm ‐‐ to maintain the process variable at a specific value or setpoint.
A third option is the integrated or hybrid switch‐transmitter, which combines a continuous transmitter and solid‐state switch within a single instrument housing. This approach effectively combines a number of the advantages of both.
Reliable Multilayer Piezo Actuators - Development and Testing
Piezoelectric multilayer actuators are the driving force behind the most challenging nanopositioning applications. These types of actuators have been in use for about two decades and have reached maturity several years ago. Continuous improvements are based on long term tests and exact knowledge of the environmental operating conditions and failure modes allows to push the limits of this technology even further.
The paper presents the results of an extensive study involving up to four environmental chambers and more than 1,000 actuator samples to develop a grid of 13 humidity and temperature conditions. Weibull-analysis is used at every condition to determine the DC-voltage dependent lifetime of the co-fired PICMA multilayer actuators. In addition to the (most critical for precision positioning applications) DC tests, behavior under large-signal AC-conditions with up to 1010 cycles for different functions as well as temperature-conditions was also evaluated. Three patented design features of the latest actuator generation are based on the findings.
Choosing the Right Pressure Sensor
Today's pressure sensors are called on to work within the harshest of environments - with the most hostile and corrosive media - or sometimes to take the simplest of pressure readings.
Selecting the right one for the right job is not necessarily an easy feat. Whether a particular pressure sensor is suitable for a specific application will depend in great part on the sensor's attributes, the environment it's being specified for, and the job it's being asked to perform.
So, how do you select sensors that address multiple customer-specific performance requirements? Here is a guide to finding just what you're looking for based on your performance requirements or design needs.
Bound to Fail: Why Cybersecurity Risk Cannot Simply Be Managed Away
Author: Ralph Langner, Perry Pederson, Brookings Instution
Rather than a much-needed initiative to break the legislative deadlock on the subject in Congress, President Obama's new executive order for improving critical infrastructure cybersecurity is a recipe for continued failure. In essence, the executive order puts the emphasis on establishing a framework for risk management and relies on voluntary participation of the private sector that owns and operates the majority of U.S. critical infrastructure. Both approaches have been attempted for more than a decade without measurable success. A fundamental reason for this failure is the reliance on the concept of risk management, which frames the whole problem in business logic. Business logic ultimately gives the private sector every reason to argue the always hypothetical risk away, rather than solving the factual problem of insanely vulnerable cyber systems that control the nation's most critical installations.
The authors in this document suggest a policy-based approach that instead sets clear guidelines for asset owners, starting with regulations for new critical infrastructure facilities, and thereby avoids perpetuating the problem in systems and architectures that will be around for decades to come. In contrast to the IT sector, the industrial control systems (ICS) that keep the nation's most critical systems running are much simpler and much less dynamic than contemporary IT systems, which makes eliminating cyber vulnerabilities, most of which are designed into products and system architectures, actually possible. Finally, they argue that a distinction between critical and non-critical systems is a bad idea that contradicts pervasiveness and sustainability of any effort to arrive at robust and well-protected systems.
Register to download this document and learn more. We'd love to have your reaction to what you've read (either positive or negative). After reading the document come back and tell us what you think.
Read what our community experts have to say:
- Can We Use Risk Analysis to Determine the Economics of Cybersecurity?
By Walt Boyes, editor in chief
- Cybersecurity Responsibility White Paper
By Joe Weiss, cybersecurity expert and blogger
- Is Field-Based Control More Secure?
By John Rezabek, proces control specialist
- Find out more about Liquiphant FailSafe FTL8x point level switches. They have two relay outputs.
- Levelprox is ideal for high-pressure, hazardous or sterile applications.
- The 2130 series of Rosemount vibrating short fork level switches features a built-in fault monitoring/self-checking diagnostics
- The Universal IVCM Model water cut monitor offers superior water cut measurement accuracy in the low ranges (0-1%, 0-5% and 0-10% water)
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