Showing posts with label transmitter. Show all posts
Showing posts with label transmitter. Show all posts

Simplified Operation and Reduced Cost With Safety Transmitters and Switches

Series One Safety TransmittersProcess safety experts continually seek sustainable ways to improve the performance of safety critical loops, achieving risk reduction and safety goals in a cost-effective manner. Some view a reduction in complexity of safety related protocols to be a positive development. Traditional or historical approaches to deploying full blown safety systems were generally associated with great expense and high complexity, and still came up short on delivering the needed levels of risk reduction. Process control device and equipment manufacturers have responded with newer technologies and products that better address the safety needs of industrial processing.

In sensor subsystems, United Electric’s certified safety transmitter for pressure or temperature provides a less costly, simple path for process designers, instrument and control engineers, and maintenance personnel. The Series One Safety Transmitters combine several useful safety and monitoring functions into a single, easy to deploy device. Products are available for gauge pressure, differential pressure, and temperature applications. In addition to a 4-20 mA process variable output, the Series One has an embedded programmable high-capacity relay certified as a safety variable output. The Series One Safety Transmitter provides designers the option of a hard wired trip in less than 100 milliseconds, with a tenth of a percent repeatability, along with the monitoring functions of a traditional continuous analog output.

For equipment under control requiring protection, or processes where rapid excursions can initiate dangerous events, this unique pressure and temperature transmitter is addressing process safety time constraints, coupling issues with PLC and DCS units, and adding diversity to the safety instrumented function.

There is a whole lot more to learn about these "Safety right out of the box" industrial pressure and temperature safety transmitters. A product data sheet is provided below, but you can get the latest and most detailed product and application information from a specialist in industrial process measurement and control. Share your safety instrumentation challenges with them, combining your process expertise with their product application knowledge to develop effective solutions.

Learn more about the UEC One Series by visiting this page on the Miller Energy web site.




Summary of Technologies Used For Continuous Liquid Level Measurement in Industrial Process Control

non-contact radar liquid level transmitter
Non-contact radar liquid level transmitter
Courtesy Magnetrol
Automated liquid processing operations in many fields have requirements for accurate and reliable level measurement. The variety of media and application criteria demand continuous improvement in the technology, while still retaining niches for older style units utilizing methods that, through their years of reliable service, inspire confidence in operators.

Here is a synopsis of the available technologies for instruments providing continuous liquid level measurement. All are generally available in the form of transmitters with 4-20 mA output signals, and most are provided with additional outputs and communications. What is notably not covered here are level switches or level gauges that do not deliver a continuous output signal corresponding to liquid level.

Whether considering a new installation or upgrading an existing one, it can be a good exercise to review several technologies as possible candidates for a project. None of the technologies would likely be considered the best choice for all applications. Evaluating and selecting the best fit for a project can be facilitated by reaching out to a product application specialist, sharing your applications challenges and combining your process knowledge with their product expertise to develop an effective solution.

Displacer – A displacer is essentially a float and a spring that are characterized for a particular liquid and range of surface level movement. The displacer moves in response to liquid level, changing the location of a core connected to the displacer by a stem. The core is within a linear variable differential transformer. The electrical output of the transformer changes as the core moves.

Guided Wave Radar – A radar based technology that uses a waveguide extending into the liquid. The radar signal travels through the waveguide, basically a tube. The liquid surface level creates a dielectric condition that generates a reflection. Calculations and processing of the emitted and returned signals provide a measure of distance to the liquid surface. No moving parts.

Magnetostrictive – A method employing measurement of the transit time of an electric pulse along a wire extending down an enclosed tube oriented vertically in the media. A magnetic float on the exterior of the tube moves with the liquid surface. The float’s magnetic field produces the return signal to the sensor. Processing the time from emission to return provides a measure of distance to the liquid surface.

Pulse Burst Radar - A radar based technology employing emissions in precisely timed bursts. The emission is reflectex from the liquid surface and transit time from emission to return is used to determine distance to media surface.  Not adversely impacted by changes in media conductivity, density, pressure, temperature. No moving parts.

Frequency Modulated Continuous Wave Radar – Another radar based technology that employs a radar signal that sweeps linearly across a range of frequencies. Signal processing determines distance to media surface.  Not adversely impacted by changes in media conductivity, density, pressure, temperature. No moving parts.

RF Capacitance - As media rises and falls in the tank, the amount of capacitance developed between the sensing probe and the ground reference (usually the side metal sidewall) also rises and falls. This change in capacitance is converted into a proportional 4-20 mA output signal. Requires contact between the media and the sensor, as well as a good ground reference. No moving parts.

Ultrasonic Non-Contact – Ultrasonic emission from above the liquid is reflected off the surface. The transit time between emission and return are used to calculate the distance to the liquid surface. No contact with media and no moving parts.

Differential Pressure – Pressure sensor at the bottom of a vessel measures the pressure developed by the height of the liquid in the tank. No moving parts. A variation of this method is often called a bubbler, which essentially measures hydrostatic pressure exerted on  the gas in a tube extending into the contained liquid. It has the advantage of avoiding contact between the measuring instrument parts, with the exception of the dip tube, and the subject liquid.

Laser - Probably one of the latest arrivals on the liquid level measurement scene, laser emission and return detection is used with time interval measuring to accurately determine the distance from the sensor source to the liquid surface.

Load Cell - A load cell or strain gauge can be incorporated into the support structure of the liquid containing vessel. Changes in the liquid level in the vessel are detected as distortions to the structure and converted, using tank geometry and specific gravity of the liquid.

All of these technologies have their own set of attributes which may make them more suitable to a particular range of applications. Consulting with a product specialist will help determine which technologies are the best fit for your application.


Use Manifold Valves With Pressure Transmitters

manifold valves for pressure transmitters and gauges
Manifold Valves for Pressure Gauges and Transmitters
Pentair - Anderson Greenwood
Pressure transmitters are generally fixed in place, but require regular access for calibration and operational testing. Unlike instruments used to measure some other process conditions, a pressure transmitter is directly connected to the process, making it's removal problematical. Manifold valves provide a compact and effective means of access and isolation needed to perform regular maintenance and calibration operations while maintaining the pressure transmitter in place.

A single pressure transmitter or gauge can be served by a simple 2-valve manifold. One valve provides isolation of the instrument from the process. The second valve opens to atmosphere on the instrument side of the isolation valve. This allows the pressure transmitter or gauge to be isolated from the process and connected to a calibration source. Here is a schematic example.
Certainly, any qualified technician can cobble together this arrangement from a pile of valves and fittings. The advantages of using a manifold valve are several.
  • High pressure rating
  • Reduced leakage potential
  • Compact size
  • Comparatively rapid installation
There are numerous manifold valve configurations to accommodate any valve and gauge requirement. Manifold valves can also be used in other applications for making effective and convenient connection arrangements between instruments and processes. Share your connectivity challenges and requirements with process instrumentation specialists, combining your process knowledge with their product application expertise to develop the best solutions.



Safety Transmitters For Temperature and Pressure

safety transmitter for industrial process control pressure temperature
Series One Safety Transmitter
United Electric Controls
Industrial history is replete with examples of catastrophic accidents. New safety technologies exist today that can prevent or mitigate mishap and disaster in fluid processing and other operations. Modern philosophy of plant safety brings a focus on a proactive approach. Process operators have a new sense of urgency to bring increased levels of safety to their operations.

The United Electric Controls (UE) Series One is a SIL-certified (Safety Integrity Level) transmitter designed solely for safety, alarm, and shutdown. With reliability, speed, and reduced nuisance trips an integral part of its design, the Series One is suitable for application in new installations, or easily integrated into existing operations.

A typical safety loop consists of sensors (such as a pressure or temperature transmitter), controllers, and final control elements. Most SIL-rated pressure transmitters require 300ms to communicate with the controller, then up to 500ms for the controller to send a signal to the final control element (such as a valve). This combined response time may insufficient for some applications. Incorporating the One Series Safety Transmitter, directly connected to the final control element, the total signal time is reduced to 100ms - a large and significant time savings when safe operating conditions have been breached. When used with blowers, pumps and compressors, the One Series makes up a complete safety system with a self-contained sensor, controller, and final control element (the switch) capable of SIL2 without additional safety instrumented function (SIF) components.

The below document provides detailed information about the Series One. Share your process safety challenges with the instrumentation specialists and combine your process knowledge with their product application expertise to produce effective solutions.



Safety Transmitters Achieve Safety Goals With Reduced Cost and Complexity


safety transmitter for temperature, pressure, differential pressure applications in industrial process control
Series One Safety Transmitter
United Electric Controls
Process safety experts continually seek sustainable ways to improve the performance of safety critical loops, achieving risk reduction and safety goals in a cost-effective manner. Some view a reduction in complexity of safety related protocols to be a positive development. Traditional or historical approaches to deploying full blown safety systems were generally associated with great expense and high complexity, and still came up short on delivering the needed levels of risk reduction. Process control device and equipment manufacturers have responded with newer technologies and products that better address the safety needs of industrial processing.

In sensor subsystems, United Electric’s certified safety transmitter for pressure or temperature provides a less costly, simple path for process designers, instrument and control engineers, and maintenance personnel. The Series One Safety Transmitters combine several useful safety and monitoring functions into a single, easy to deploy device. Products are available for gauge pressure, differential pressure, and temperature applications. In addition to a 4-20 mA process variable output, the Series One has an embedded programmable high-capacity relay certified as a safety variable output. The Series One Safety Transmitter provides designers the option of a hard wired trip in less than 100 milliseconds, with a tenth of a percent repeatability, along with the monitoring functions of a traditional continuous analog output.

For equipment under control requiring protection, or processes where rapid excursions can initiate dangerous events, this unique pressure and temperature transmitter is addressing process safety time constraints, coupling issues with PLC and DCS units, and adding diversity to the safety instrumented function.

There is a whole lot more to learn about these "Safety right out of the box" industrial pressure and temperature safety transmitters. A product data sheet is provided below, but you can get the latest and most detailed product and application information from a specialist in industrial process measurement and control. Share your safety instrumentation challenges with them, combining your process expertise with their product application knowledge to develop effective solutions.