United Electric Controls Pressure & Temperature Plant Safety Solutions

Whether it’s protecting valuable equipment, processes or your loyal employees, creating a safe work environment is a corporate responsibility. Installing safety instrumentation not only protects critical equipment and processes; it also creates a safe work environment for your employees and a healthier environment for us all.

UE’s One Series digital pressure and temperature switch comes with complete Failure Modes, Effects and Diagnostics Analysis (FMEDA) data from Exida, enabling plant safety personnel to reliably calculate Safety Integrity Levels (SIL). The rugged One Series is installed in the field, at the point of critical monitoring, with response times 5X faster than a transmitter, providing immediate, local shutdown, while streamlining wiring and software. For your plant safety requirements, simplify and improve reliability with the One Series for all critical pressure and temperature shutdown applications.

Direct-Acting Safety Shutdown

The rugged and reliable One Series pressure and One Series temperature switch protects equipment, processes and personnel. It is installed where needed, in the field, with direct-acting on/off digital switching. With 0.1% repeatability combinded with solid-state reliability and on-board diagnostics, the One Series is the clear choice for critical plant safety applications.

Faster Response Time Than A Transmitter

Plant safety requires immediate response to dangerous conditions. The One Series response time is 60 mS, five-times faster than a process transmitter. And, with direct switching capability at the point of critical conditions, it provides an alternative technology to the overreliance on transmitters and central control systems, eliminating the possibility of “Common Mode Failure.”

 

ONE SERIES

Electronic Pressure, DP & Temperature Switches

• Fully adjustable set point and deadband

• 5X faster than a transmitter and 50% less installed cost

• Digital display includes process, status and self-diagnostics

• 2-wire and loop-powered 4-20 mA models available

• Measures gage pressure, differential pressure or temperature

• 0.1% repeatability with temperature compensation

• Provides the functions of a switch, gauge and transmitter

• Ranges to 6000 psi (410 bar), 200 psid (13.8 bar), 1000˚F (538˚C)

On-Board Diagnostics

The One Series continually checks health status for circuit and sensor integrity, providing extra assurance that it stands ready to perform when needed. In addition, it provides a “pulsed” output that can be activated to help distinguish a critical alarm or shutdown signal above the frequent control room “noise” of false trip signals that may be ignored or disabled at operator discretion.

Suitable For SIL2 Applications

Request the "EXIDA" Failure Modes, Effects, Diagnostics Analysis (FMEDA) report from UE covering the One Series, enabling you to calculate the Safety Integrity Level (SIL) for your applications. Also request the SIL Verification Summary report to compare the One Series with generic switches and transmitters. Go to www.ueonline.com for copies of these 3rd party reports.

I AM WORKING (IAW):

The Role of Self-Diagnostics in SIS Applications

All One Series electronic switches include powerful self-diagnostics. Critial functions of the One Series are checked during initialization, and then continuously monitored by the IAW® algorithm. Detected faults are reported using three methods of annunciation:

1. The local digital display provides clear fault indications at a glance
2. Each fail-safe switch will open, providing a remote fault indication
3. On models that include 4-20 mA output, the analog signal will indicate 0, 3.5, 22 or 24 mA, depending on the type of fault.

IAW PROGRAMMING MODE AND RESULTING SWITCH STATES

The fail-safe-open IAW® programming mode provides a predictable annunciation that differentiates between an upset process variable and a detected fault using a single discrete “switch” output.

• When process and instrument conditions are normal, the One Series switch is pulsed, sending out a continuous heartbeat signal that is easily detected by the safety PLC.
 
• When the process variable reaches the programmed set point, the One Series switch will close, indicating that the process is upset but the One Series remains functioning (no faults detected).
 
• If the switch opens, this condition indicates a fault detected by the IAW® self-diagnostics. The reporting scheme also accounts for wiring integrity. If a wire is broken or power is lost, this type of “fault” would also appear as an open switch to the safety PLC.

For more infromation on how the One Series from United Electric Controls can maximize your plant safety efforts please contact Forber Scientific, Inc. customer Service

Toll Free: 855-288-5330

Email: mechanicalsales@forberg.com

Vist: www.forberg.com

 

Active & passive temperature compensation of pressure sensors

Author: Dominik Lorenz
Posted: Knowledge

How does an active or passive temperature compensation of pressure transmitters actually work? High-quality pressure transmitters, especially those used in precision critical applications, are almost always provided with an individual temperature compensation. But what is actually the difference between an active and a passive temperature compensation of these sensors?

Passive temperature compensation:
Sections of the characteristic accuracy curve of the pressure sensor are measured at different temperatures during the manufacturing process. Then, the previously determined temperature errors are compensated by passive elements (resistors) within the electronics of the sensor or by corrections of specifically designed resistance structures directly on the sensor element itself (e.g. by laser-trimming). The (passive) resistor elements used have an almost linear temperature behaviour, it is, however, only possible to compensate 1st order errors. Temperature errors of higher order, i.e. strong bending of the characteristic curve under temperature, can not be compensated.

Active temperature compensation:
Here too, the characteristic curve of the pressure transmitters is measured at different temperatures during the manufacturing process. However, the pressure transmitter has an additional integrated temperature sensor which constantly measures the temperature of the sensor and transfers it to the pressure transmitter’s signal processing. In practice, two methods of active temperature compensation are common: the first method compensates by means of a limited number of samples, , i.e. discrete correction values, between which interpolation takes place. The second method uses the electronics of the transmitter and a higher-order equation resulting from the regression of the acquired measurement values in order to compensate then the expected error.

During operation, this signal processing makes it possible to automatically, i.e. “actively”, compensate the pressure transmitter‘s temperature error using the calculated correction factors within a specified temperature range 50-140°F (e.g. 10-60°C).

The most commonly used method to minimise temperature errors of pressure sensors is a passive temperature compensation. This is the traditional method which is widely used. However, active temperature compensation is the top class of possible compensation methods. WIKA has constantly improved and refined this technology in recent years.

The pressure transmitters of WIKA using active temperature compensation therefore feature a temperature error which is almost zero in their specified temperature range.

If you would like to get more information about WIKA pressure transmitters or other WIKA products please contace Forberg Scientific, Inc. customer service.
Toll Free: 1-855-288-5330
Email: mechanicalsales@forberg.com

Pressure Transmitters Applications for Wind Turbines

Pressure Transducer Usage Wind Turbines for Alternative Energy Generation in Energy and Power Generation

Author: Wika

From: Application Notes

Wind Turbines

As today’s society looks for forms of alternative energy and ways to distance ourselves from fossil fuels, wind power has emerged as a major player in the alternative energy market. Wind turbines function by converting the kinetic energy of wind into mechanical energy to rotate the wind turbine rotor. The rotor connects to an alternator or electrical motor which converts the mechanical energy into electrical energy for storage and consumption.

Maximizing wind turbine efficiency requires turbine placement where steady winds are present and wind turbine alignment with the wind. Alignment with the wind requires use of a wind vane and yaw controller, frequently hydraulically powered and monitored through use of a pressure transducer. As wind speeds approach the survival speed, the speed at which the wind turbine with begin to fail both mechanically and structurally, the blade angle of attack or pitch must be increased in order to stall the blade and prevent the turbine from spinning out of control. Hydraulic control systems use pressure transducers for wind turbine pitch control. The following diagram indicates the basic components of wind turbines.

Pressure Transducer Application to Wind Turbines in Alternative Energy Generation Applications

Pressure Transducers are used for Wind Turbines in Energy and Power Generation in the following Alternative Energy Generation Applications

• Yaw Hydraulic Cylinder Pressure Measurement and Control
• Pitch Hydraulic Cylinder Pressure Measurement and Control

Alternative Energy Generation Wind Turbines in Energy and Power Generation applications call for pressure transducer material compatibility with standard hydraulic fluids and with 24-hour-a-day, reliable operation. Pressure transducers are responsible for indicating pressures within the hydraulic cylinders in charge of yaw and pitch control. The WIKA S-10 and WIKA A-10 electronic pressure transducers have been designed for reliable performance in Energy and Power Generation Alternative Energy Generation applications like Wind Turbines.

Pressure Transmitter Selection Considerations

• High reliability
• Temperature compensation
• Vibration resistance
• Compatibility with hydraulic fluid

If you would like more information about Wika Pressure Transmitters or other Wika Products please contact Forberg Scientific, Inc. customer service.

Toll Free: 1-855-288-5330
Email: mechanicalsales@forberg.com