Miller Energy Expands Product Offering

Miller Energy is now a distributor of Asco solenoid
valves for a wide range of general and special applications

Miller Energy, through its acquisition of a New Jersey based distributor, has greatly expanded the company's offering of solenoid valves, pneumatic system components, and fluid handling and control components.

A solenoid is an electrical device, converting electrical energy input to a linear mechanical force. Solenoids are used to provide rapid two state mechanical movement of other devices. In process control applications, those devices are often fluid control valves.

At the basic level, a solenoid is an electromagnetic coil and a metallic rod or arm. Electrical current flow in the coil creates a magnetic field which will position the rod in one of two locations, depending upon whether the coil is energized. The movable component of the solenoid is linked to, or part of, the operating mechanism of another device. This allows the switched electrical output of a controller to regulate mechanical movement in another device and cause a change in its operation. A common solenoid application is the operation of small valves.

A plunger solenoid contains a movable ferrous rod, sometimes called a core, enclosed in a tube sealed to the valve body and extending through the center of the electromagnetic coil. When the solenoid is energized, the core moves to its equilibrium position in the magnetic field. The core is also a functional part of valve operation. It's repositioning causes a designed changed in the valve operating status (open or close). There are countless variants of solenoid operated valves exhibiting particular operating attributes designed for specific types of applications. In essence, though, they all rely on the electromechanical operating principle outlined here.

A solenoid valve is a combination of two functional units.

• The solenoid (electromagnet) described above.
• The valve body containing one or more openings, called ports, for inlet and outlet, and the valve interior operating components.

Flow through an orifice is controlled by the movement of the rod or core. The core is enclosed in a tube sealed to the valve body, providing a leak tight assembly. A controller energizing or de-energizing the coil will cause the valve to change operating state between open and closed, regulating fluid flow. There are almost countless variants of solenoid operated valves, specifically tailored for applications throughout industrial, commercial, and institutional operations.

The document provided below illustrates a portion of the broad array of solenoid valves available for industrial control applications. Share your fluid control requirements and challenges with an application specialist. Leverage your process knowledge and experience with their product application expertise to produce effective solutions.

ASCO Solenoid Valve Product Line Overview from Miller Energy, Inc.

Bulb and Capillary Temperature Switches

General purpose temperature switch with bottom connection
for capillary and bulb specific for each application.
Image courtesy United Electric Controls

Not all processes or operations require the use of state of the art technology to get the desired results. Part of good process design is matching up the most appropriate methods and technology to the operation.

One method of changing the state of a switch in response to a process temperature change is a bulb and capillary temperature switch. The switch operation produces a state change in the mechanical switch when the temperature of a process control operation crosses a certain threshold. Bulb and capillary switches have the advantage of operating without electricity, simplifying their application.

The physical operating principle behind the capillary thermostat relies on the use of a fluid. The fluid inside the thermostat expands or contracts in response to the temperature at the sensing bulb. The change in fluid volume produces a force upon a diaphragm or other mechanical transfer device. The diaphragm is connected to, and changes the status of, an adjoining circuit using a snap action switch. For example, a main use of the operating principle in action is when a commercial food company relies on the capillary switch to control temperature related to processing and distribution. Each individual use of a bulb and capillary thermostat is specifically designed based on manufacturer and industry specifications, all of which apply the same physical principle of fluid based physics.

Because of their simplicity and comparatively modest cost, commercial versions of bulb and capillary switches find application throughout residential and commercial settings. Some common applications include warming ovens, deep fat fryers, and water heaters. The HVAC industry uses capillary and bulb switches because the rate of temperature change found in their applications fits the adjoining range offered by the bulb and capillary type switches. Operation of the temperature switches is subject to a few limitations. The switching point is often fixed, so the application must be without a requirement for an adjustable setpoint. The temperature range over which the switches are suitable is comparatively limited, with a matching of the bulb and capillary fluid system to the application temperature range a necessary task in product selection. Within its proper sphere of use, though, bulb and capillary temperature switches offer simple, reliable operation, with little requirement for maintenance.

Bulb and capillary switches are typically used to evaluate average temperature and are especially useful for applications where the temperature is to be maintained at a well-known, consistent value. The bulb portion can be configured to accommodate mounting within the media to be controlled. The devices can be applied effectively to liquid and gaseous media when the proper bulb is used.

Industrial versions of bulb and capillary switches are fitted with appropriate housings for the installation environment. Hazardous location installation can be accommodated, as well as high current ratings and auxiliary functions. There are almost countless variants of bulb and capillary temperature switches available. Don’t overlook these simple mechanical devices as candidates for application in any temperature control process. Share your application requirements and challenges with product specialists for useful recommendations.

Temperature, Pressure, Vacuum, and Differential Switches from Miller Energy, Inc.

Application of Load Cells in Process Measurement

The advanced model G5 can handle input signals from multiple load cells
Image courtesy of BLH Nobel

In industrial application of process measurement and control, principles of the physical sciences are combined with technology and engineering to create devices essential to modern high speed, high accuracy system operation. Years of research, development, and the forward march of humanity’s quest for scientific knowledge and understanding yields packaged devices for process measurement that are easily applied by system designer and operators.

Load cells are the key components applied to weighing component or processed materials in modern industrial operations. Load cells are utilized throughout many industries related to process management, or just simple weighing operations. In application, a load cell can be adapted for measurement of items from the very small to the very large.

In essence, a load cell is a measurement tool which functions as a transducer, predictably converting force into a unit of measurable electrical output. While many types of load cells are available, one popular cell in multiple industries is a strain gauge based cell. Strain gauge cells typically function with an accuracy range between 0.03% and 0.25%. Pneumatically based load cells are ideal for situations requiring intrinsic safety and optimal hygiene. For locations without a power grid, there are even hydraulic load cells, which function without need for a power supply. These different types of load cells follow the same principle of operation: a force acts upon the cell (typically the weight of material or an object) which is then returned as a value. Processing the value yields an indication of weight in engineering units.

For strain gauge cells, deformation is the applied operational principal, where extremely small amounts of deformation, directly related to the stress or strain being applied to the cell, are output as an electrical signal with value proportional to the load applied to the cell. The operating principle allows for development of devices delivering accurate, precise measurements of a wide range of industrial products.

Load cell advantages include their longevity, accuracy, and adaptability to many applications, all of which contribute to their usefulness in so many industries and applications. A common place to find a strain gauge load cell in use is off a causeway on a major highway at a truck weigh station. Through innovation, load cells have been incorporated in an efficient measuring system able to weigh trucks passing through the station, without having each stop. Aircraft can be weighed on platform scales which utilize load cells, and even trains can be weighed by taking advantage of the robust and dependable nature of the transducers.

Thanks to their widespread incorporation and the sequential evolution of technology, load cells are a fantastically useful tool in process measurement and control. Share your process weighing challenges with application experts, combining your own process expertise with their product knowledge to develop an effective solution.

Product Update: SMARTDAC+ GX/GP Series Recorders & GM Series Data Acquisition System Release 4

Updated SMARTDAC line of data acquisition instruments
Image courtesy Yokogawa

Yokogawa Electric Corporation announced it's Release 4 of the SMARTDAC+® GX series panel-mount type paperless recorder, GP series portable paperless recorder, and GM series data acquisition system.

With this latest release, new modules are provided to expand the range of applications possible with SMARTDAC+ systems and improve user convenience. New functions include sampling intervals as short as 1 millisecond and the control and monitoring of up to 20 loops.

Overview

Recorders and data acquisition systems (data loggers) are used on production lines and at product development facilities in a variety of industries to acquire, display, and record data on temperature, voltage, current, flow rate, pressure, and other variables. Yokogawa offers a wide range of such products, and is one of the world’s top manufacturers of recorders. Since releasing the SMARTDAC+ data acquisition and control system in 2012, Yokogawa has continued to strengthen it by coming out with a variety of recorders and data acquisition devices that meet market needs and comply with industry-specific requirements and standards.

With this release, Yokogawa provides new modules with strengthened functions that meet customer needs for the acquisition and analysis of detailed data from evaluation tests. These modules decrease the cost of introducing a control application by eliminating the need for the purchase of additional equipment.

Enhancements

The functional enhancements available with Release 4 are as follows:

High-speed analog input module for high-speed sampling.

To improve the safety of electric devices such as the rechargeable batteries used in everything from automobiles to mobile devices, evaluation tests must be conducted to acquire and analyze detailed performance data. For this purpose, sampling at intervals as short as 1 millisecond is desirable. However, this normally requires an expensive, high-performance measuring instrument. When the new high-speed analog input module, a SMARTDAC+ system can sample data at intervals as brief as 1 millisecond, which is 1/100th that of any preceding Yokogawa product. This is suitable for such high performance applications such as measurement of the transient current in rechargeable batteries to vibration in power plant turbines. A dual interval function has also been added that enables the SMARTDAC+ to efficiently and simultaneously collect data on slowly changing signals (e.g., temperature) and quickly changing signals (e.g., pressure and vibration).

PID control module for control function

In applications that need both control and recording, such as controlling the temperature of an industrial furnace or the dosage process at a water treatment plant, there is a need for systems that do not require engineering and can be quickly and easily commissioned. In a typical control and monitoring application, a separate recorder and controller is required to control temperature, flow rate and pressure. At the same time, a data acquisition station must communicate with the controller to ensure data is being capture and recorded. It is time consuming and oftentimes confusing, to ensure the controller and the data acquisition station is communicating seamlessly. By combining continuous recording function of the SMARTDAC+ and PID control module into a single platform, customers can now seamlessly control and record critical process data in one system. The SMARTDAC+ can control, monitor and record up to 20 loops. Each PID control module comes with 2 analog inputs, 2 analog outputs, 8 digital inputs and 8 digital outputs.

Four-wire RTD/resistance module for precise temperature measurement

While three-wire RTDs are widely used in many fields such as research institutes to manufacturing, some applications require higher level of precision and accuracy that is only possible with 4-wire RTDs. A 4-wire RTD is the sensor of choice for laboratory applications where accuracy, precision, and repeatability are extremely important. To satisfy this need, Yokogawa has released a 4-wire RTD/resistance module for the SMARTDAC+.

Target Markets

GX series: Production of iron and steel, petrochemicals, chemicals, pulp and paper, foods, pharmaceuticals, and electrical equipment/electronics; water supply and wastewater treatment facilities.

GP series: Development of home appliances, automobiles, semiconductors, and energy-related technologies; universities; research institutes.

GM series: Both of the above target markets.

For more information on the SMARTDAC+ GX/GP Series Recorders & GM Series Data Acquisition System contact Miller Energy at (800) 631-5454 or by visiting the company website.

WirelessHART Toxic and Combustible Gas Detector

Vanguard WirelessHART toxic and combustible
gas detector for industrial safety use.
Image courtesy United Electric Controls

Earlier this year, United Electric Controls released its Vanguard WirelessHART gas detector for use in a wide range of industrial settings. Detecting potentially hazardous levels of toxic or combustible gases is an essential element of plant safety where these gases are employed. The Vanguard detector integrates seamlessly into existing WirelessHART networks and asset management systems. A battery lifespan of 5 years and a design that provides in-place test and calibration mean there will be little burden to maintaining the proper operation of the unit.

More detail is provided in the brochure included below. The Vanguard incorporates solid construction and design features to deliver ease of use and long service life. Share your gas detection and process measurement challenges with instrumentation specialists. Combining your own process experience and knowledge with their product application expertise will result in an effective solution.

WirelessHART Gas Detector for Toxic and Combustible Gas from Miller Energy, Inc.

Level and Flow Instruments for Hygienic Applications

Magnetrol is a globally recognized leader in the manufacture of flow and level instrumentation for industrial scale applications. The products employ a range of differing technologies to provide measurement precision across an array of challenging applications. The informational piece included below highlights Magnetrol's products intended for use in industries, such as pharma or food processing, where special materials and product design are employed to meet the special requirements of hygienic processing.

Share your flow and level measurement challenges with process instrumentation experts, combining your own knowledge and experience with their expertise to develop effective solutions.

Life Science Applications and Products - Magnetrol from Miller Energy, Inc.

Pump Protection Using Thermal Dispersion Flow Switches

Thermal dispersion flow switches have advantages
when applied for pump protection
Image courtesy Magnetrol

Good practice for installing industrial pumps calls for inclusion of protective devices to assure that the pump is not exposed to conditions beyond its design intent. Monitoring liquid flow is a useful method for determining if a pump is operating within a safe range.

There are numerous methods of verifying flow in piping connected to a pump. Magnetrol, globally recognized manufacturer of flow and level measurement technologies, offers up their assessment of various pump protection measures and a recommendation for what they consider an advantageous choice for flow measurement in a pump protection application.

Magentrol's white paper is included below, and you can share your flow and level measurement challenges with application experts for help in developing effective solutions.

Pump Protection Using Thermal Dispersion Switches from Miller Energy, Inc.

Sometimes the Simple Solution Is the Best

This metal tube variable area flow meter is reliable,
accurate, and requires little maintenance
Photo courtesy Brooks Instrument

For process control and commercial or industrial applications, there are numerous methods of flow measurement from which to choose. Technologies range from very simple applications of physical principles to deployment of very specialized electronics and sensors. The available range of accuracy, response, and cost is quite broad, with a general expectation that higher cost will deliver better performance and accuracy.

Making the best instrument selection for a flow measurement application should include an assessment of what the operators really need in order to safely and effectively run the process or perform the task related to the measurement of fluid flow. Installing instrumentation with capabilities far beyond what is required is almost certainly a waste of financial resources, but may also have an unexpected impact on operators. Through the generation of data that, while accurate, does not provide any actionable information about process condition, operators can be misled, similar to the occurrence of a false or nuisance alarm. Some applications call for high accuracy, some do not. Define your informational needs and select instruments that will meet those needs.

There is a large array of applications that can be satisfied with simpler, less costly measurement technology. These devices often employ turbines or vanes to produce an indication of flow rate. Incorporated into some of the instruments is a means to visually observe the flowing liquid to verify color and clarity. Simple devices sometimes are intended only to indicate the presence of fluid flow, and whether the flow rate is high or low. Configurations are available that allow insertion into lines under pressure (hot tap) through a full port ball valve. Other variants with combinations of features and capabilities abound.

The selection range is enormous, so define your minimum needs first, then search for a compatible product. Your search can be enhanced by contacting an instrumentation specialist. Combining your process expertise with their broad product knowledge will produce effective solutions.

Metal Tube Variable Area Flow Meter from Miller Energy, Inc.

Heat Processing of Industrial Fluids

Steam produced by gas fired industrial boilers is a
commonly applied means of delivering heat energy

Heat, as an entity, was not always something seen as a partially visible potential indicator of changing weather patterns. The now outdated caloric theory portrayed heat as a measure of an invisible fluid called the caloric, typifying it as a solely physical property. Thermodynamics have surpassed the caloric theory and rendered it obsolete, but the understanding and manipulation of heat in industrial settings, especially pertaining to fluids, is a central part of some of the world’s most important industries. Specifically, the measurement and control of heat related to fluid processing is a vital industrial function, and relies on regulating the heat content of a fluid to achieve a desired temperature and outcome.

The manipulation of a substance’s heat content is based on the central principle of specific heat, which is a measure of heat energy content per unit of mass. Heat is a quantified expression of a system’s internal energy. Though heat is not considered a fluid, it behaves, and can be manipulated, in some similar respects. Heat “flows” from points of higher temperature to those of lower temperature, just as a fluid will flow from a point of higher pressure to one of lower pressure.

A heat exchanger provides an example of how the temperature of two fluids can be manipulated to regulate the flow or transfer of heat. Despite the design differences in heat exchanger types, the basic rules and objectives are the same. Heat energy from one fluid is passed to another across a barrier that prevents contact and mixing of the two fluids. By regulating temperature and flow of one stream, an operator can exert control over the heat content, or temperature, of another. These flows can either be gases or liquids. Heat exchangers raise or lower the temperature of these streams by transferring heat between them.

Recognizing the heat content of a fluid as a representation of energy helps with understanding how the moderation of energy content can be vital to process control. Controlling temperature in a process can also provide control of reactions among process components, or physical properties of fluids that can lead to desired or improved outcomes.

Heat can be added to a system in a number of familiar ways. Heat exchangers enable the use of steam, gas, hot water, oil, and other fluids to deliver heat energy. Other methods may employ direct contact between a heated object (such as an electric heating element) or medium and the process fluid. While these means sound different, they all achieve heat transfer by applying at least one of three core transfer mechanisms: conduction, convection, and radiation. Conduction involves the transfer of heat energy through physical contact among materials. Shell and tube heat exchangers rely on the conduction of heat by the tube walls to transfer energy between the fluid inside the tube and the fluid contained within the shell. Convection relates to heat transfer due to the movement of fluids, the mixing of fluids with differing temperature. Radiant heat transfer relies on electromagnetic waves and does not require a transfer medium, such as air or liquid. These central explanations are the foundation for the various processes used to regulate systems in industrial control environments.

The manner in which heat is to be applied or removed is an important consideration in the design of a process system. The ability to control temperature and rate at which heat is transferred in a process depends in large part on the methods, materials, and media used to accomplish the task. Selecting and properly applying the best suited controls, instruments and equipment is a key element of successful process operation. Share your challenges with application experts, combining your own process knowledge and experience with their product expertise to develop effective solutions.

New Pulsar R86 Non-contact Radar Level Transmitter From Magnetrol

Magnetrol's new non-contact radar level transmitter,,
Pulsar R86
Courtesy Magnetrol

Level measurement is a part of countless industrial processes and installations. Accurate measurement of contained solids or liquid enhances safety and operational efficiency, both of which contribute to the bottom line.

Magnetrol, globally recognized innovator in flow and level measurement, recently released its latest version of non-contact radar level measuring instruments. The Pulsar R86 transmitter operates in the 26GHz range, delivering a smaller wavelength with improved resolution, smaller antenna, and a narrower beam. Other unique innovations have been incorporated into the instrument to simplify installation and application.

The R86 is suitable for a broad range of applications across almost every industry. On board diagnostics are incrementally advanced to provide best performance and deliver the information needed to maintain proper operation.

The latest information on the Pulsar R86 is included below. Reach out to process measurement specialists and share your measurement challenges and requirements. Combining your own process knowledge and experience with their product application expertise will result in an effective solution.

Magnetrol Non-Contact Radar Level Transmitter Pulsar R86 from Miller Energy, Inc.

Water Quality Analysis – Constituent Survey (Part 2)

Water can contain many contaminants

It would be difficult to understate the role and importance of water in industrial processing, even our own biological existence. In the first installment of this series, the roles of dissolved oxygen and chlorides were covered.

Continuing the examination of water quality monitoring in municipal and industrial processes, another key variable which requires monitoring for industrial water use is sulfate. Sulfate is a combination of sulfur and oxygen, salts of sulfuric acid. Similarly to chlorides, they can impact water utilization processes due to their capability for corrosion. The power generation industry is particularly attuned to the role of sulfates in their steam cycle, as should be any boiler operator. Minerals can concentrate in steam drums and accelerate corrosion. Thanks to advancements in monitoring technology, instruments are available which monitor for both chlorides (covered in the previous installment in this series) and sulfates with minimal supervision needed by the operator, ensuring accurate detection of constituent levels outside of an acceptable range. Ionic separation technologies precisely appraise the amount of sulfate ions in the stream, allowing for continuous evaluation and for corrective action to be taken early-on, avoiding expensive repairs and downtime.

Another substance worthy of measurement and monitoring in process water is sodium. Pure water production equipment, specifically cation exchange units, can be performance monitored with an online sodium analyzer. Output from the cation bed containing sodium, an indication of deteriorating performance, can be diverted and the bed regenerated. Steam production and power generation operations also benefit from sodium monitoring in an effort to combat corrosion in turbines, steam tubes, and other components. Sodium analyzers are very sensitive, able to detect trace levels.

Ammonia is comprised of nitrogen and hydrogen and, while colorless, carries a distinct odor. Industries such as agriculture utilize ammonia for fertilizing purposes, and many other specializations, including food processing, chemical synthesis, and metal finishing, utilize ammonia for their procedural and product-oriented needs. An essential understanding of ammonia, however, includes the fact that the chemical is deadly to many forms of aquatic life. Removing ammonia from industrial wastewater is a processing burden of many industries due to the environmental toxicity.

Methods for removing ammonia from wastewater include a biological treatment method called ‘conventional activated sludge’, aeration, sequencing batch reactor, and ion exchange. Several methods exist for in-line or sample based measurement of ammonia concentration in water. Each has particular procedures, dependencies, and limitations which must be considered for each application in order to put the most useful measurement method into operation.

As water is an essential part of almost every facet of human endeavor and the environment in which we all dwell, the study and application of related analytics is an important component of many water based processes. The variety of compounds which can be considered contaminants or harmful elements when dissolved or contained in water presents multiple challenges for engineers and process operators.

The detection and measurement of water constituents can pose challenges to plant operators. Share your requirements with instrumentation experts, and combine your own process knowledge and experience with their product application expertise to formulate an effective solution.

Water Quality Analysis – Constituent Survey (Part 1)

Water quality analysis is utilized at sewage treatment plants,
but at many other industrial facilities, too.

Of all the raw materials available for human consumption – aside from the air we breathe – the most vital component of life on earth is water. In addition to the global need for humans to drink water in order to survive, the use of water is essential in a myriad of industries relating to process control. Whether the goal is the production or monitoring of pure water for industrial use, or the processing of wastewater, the ability to measure the presence and level of certain chemical constituents of water is necessary for success.

In order to use water properly, industrial professionals combine state of the art analyzers with technical expertise to evaluate water quality for use or disposal. Two essential values of process control are ensuring elements of a control system are accurate and secure, and, furthermore, that they are accurate and secure for each product every time. By properly vetting water in industry, engineers and other personnel in fields such as pharmaceuticals, chemical, food & beverage, brewing, power, and microelectronics are able to maintain standards of production excellence and conform with regulatory requirements related to water quality.

The amount of dissolved oxygen present in water can correlate with the degree of movement at an air-water interface, also being impacted by pressure, temperature, and salinity. Excessive or deficient dissolved oxygen levels in industrial process waters may have an impact on process performance or end product quality. Likely, the most common application for dissolved oxygen measurement is in the evaluation of wastewater for biological oxygen demand. The primary function of dissolved oxygen in wastewater is to enable and enhance the oxidation of organic material by aerobic bacteria, a necessary step in treatment.

To measure dissolved oxygen, specialized sensors and companion instruments are employed that require careful maintenance and trained technical operators. The level of measurement precision varies depending on the industry employing the technology, with numerous applications also being found in the food & beverage and pharmaceutical industries. In-line continuous measurement is used in wastewater processing to determine if the dissolved oxygen remains in a range that supports the bacteria necessary for biodegradation.

Chloride concentration in wastewater is strictly regulated. Industrial and commercial operation effluent can be regulated with respect to allowable chloride content. While commonly found in both streams and wastewater, chlorides, in large amounts, can present challenges to water utilization or processing facilities. Chloride levels impact corrosion, conductivity, and taste (for industries in which such a variable is paramount). In a process system, having an essential component marred due to elevated quantities of a substance could reverberate into any end-product being manufactured. Chloride analyzers, some of which can also detect and monitor other water characteristics, serve as important tools for water consuming facilities to meet regulatory standards for effluent discharge or internal quality standards for recycling.

There are other constituents of what we refer to as “water” that are subject to measurement and monitoring for a range of institutional, industrial, and municipal applications. Those will be explored in the next part of this article series.

Wireless Transmitters In Process Measurement and Control

Wireless industrial temperature transmitter
Courtesy Yokogawa

In process control, various devices produce signals which represent flow, temperature, pressure, and other measurable elements of the process. In delivering the process value from the measurement point to the point of decision, also known as the controller, systems have traditionally relied on wires. More recently, industrial wireless networks have evolved, though point-to-point wireless systems are still available and in use. A common operating protocol today is known as WirelessHARTTM, which features the same hallmarks of control and diagnostics featured in wired systems without any accompanying cables. Other wireless standards are employed in industrial settings, as well.

Wireless devices and wired devices can cohabitate the same network. The installation costs of wireless networks are decidedly lower than wired networks due to the reduction in labor and materials for the wireless arrangement. Wireless networks are also more efficient than their wired peers in regards to auxiliary measurements, involving measurement of substances at several points. Adding robustness to wireless, self-organizing networks is easy, because when new wireless components are introduced to a network, they can link to the existing network without needing to be reconfigured manually. Gateways can accommodate a large number of devices, allowing a very elastic range for expansion.

In a coal fired plant, plant operators walk a tightrope in monitoring multiple elements of the process. They calibrate limestone feed rates in conjunction with desulfurization systems, using target values determined experientially. A difficult process environment results from elevated slurry temperature, and the associated pH sensors can only last for a limited time under such conditions. Thanks to the expandability of wireless transmitters, the incremental cost is reduced thanks to the flexibility of installing new measurement loops. In regards to maintenance, the status of wireless devices is consistently transmitted alongside the process variable. Fewer manual checks are needed, and preventative measures may be reduced compared to wired networks.

Time Synchronized Mesh Protocol (TSMP) ensures correct timing for individual transmissions, which lets every transmitter’s radio and processor ‘rest’ between either sending or receiving a transmission. To compensate for the lack of a physical wire, in terms of security, wireless networks are equipped with a combination of authentication, encryption, verification, and key management. The amalgamation of these security practices delivers wireless network security equal to that of a wired system. The multilayered approach, anchored by gateway key-management, presents a defense sequence. Thanks to the advancements in modern field networking technology, interference due to noise from other networks has been minimized to the point of being a rare concern. Even with the rarity, fail-safes are included in WirelessHARTTM.

All security functions are handled by the network autonomously, meaning manual configuration is unnecessary. In addition to process control environments, power plants will typically use two simultaneous wireless networks. Transmitters allow both safety showers and eyewash stations to trigger an alarm at the point of control when activated. Thanks to reduced cost, and their ease of applicability in environments challenging to wired systems, along with their developed performance and security, wireless industrial connectivity will continue to expand.

Share your process measurement and control challenges with knowledgeable professionals, combining your own process knowledge and experience with their product application expertise to develop effective solutions.

Trace Moisture Analyzer

Portable and fixed installation trace moisture analyzers
Courtesy Teledyne Analytical Instruments

Moisture, the presence of water molecules, can impact certain products and processes in undesirable ways. Trace moisture analysis of clean gases can be accomplished using aluminum oxide sensors, one of several technologies available.

Instruments are available for continuous monitoring of moisture levels, or spot checking. Aluminum oxide moisture sensors rely on the change in capacitance within the sensor, which varies with the moisture content.

A concern with aluminum oxide sensor technology is drift associated with temperature and aging. A great degree of this has been alleviated through changes in sensor structure. The technology and instrumentation is easily applied and requires little in the way of maintenance other then periodic calibration.

More detail and explanation of the technology and instruments can be found in the brochure included below. Share your process analytical measurement challenges with experienced product specialists, combining your own process knowledge and experience with their up to date product expertise to develop effective solutions.

Trace Moisture Analyzer For Industrial Use from Miller Energy, Inc.

Myths About Process Switches

Example of a general purpose switch for industrial use
Courtesy United Electric Controls

We may have developed an obsession with data and information. Understatement, right? Whether a process variable is high or low no longer is satisfactory. We want to know how high, how low, how long, how fast is it changing, and more. In many cases, this is useful information that can be applied toward goals of safety and efficiency. Let us not, however, overlook the possibility that some facets of an operation are best served by that old soldier, the process switch.

Process switches are readily available for temperature, pressure, and differential pressure in ranges to suit almost any application. They are rugged time and field proven devices designed to do one thing extremely well. Process switches will reliably and instantly change the state of their mechanical switch when the process value reaches their setpoint. Once properly installed and set, process switches require little, if any, maintenance and can provide extended periods of reliable service.

United Electric Controls, globally recognized leader in the manufacture of process switches for temperature, pressure, and differential pressure, authored an informative piece that debunks some myths about process switches. The piece is included below and makes interesting reading.

Establishing the best instrumentation and control layout for a process benefits from careful consideration of many factors. Share your requirements and challenges with process measurement and control specialists, combining you own process knowledge and experience with their current product application expertise to develop effective solutions.

Myths About Process Switches from Miller Energy, Inc.

Standalone Industrial Process Controllers

Standalone process controller with
integrated input processing, display,
and outputs.
Courtesy Yokogawa

The regulation of temperature is a common operation throughout many facets of modern life. Environmental control in commercial, industrial, and institutional buildings, even residential spaces, uses the regulation of temperature as the primary measure of successful operation. There are also countless applications for the control of temperature found throughout manufacturing, processing, and research. Everywhere that temperature needs to be regulated, a device or method is needed that will control the delivery of a heating or cooling means.

For industrial process applications, the temperature control function is found in two basic forms. It can reside as an operational feature within a programmable logic controller or other centralized process control device or system. Another form is a standalone process temperature controller, with self-contained input, output, processing, and user interface. A temperature switch could be considered as a rudimentary, yet very effective standalone temperature controller. Depending upon the needs of the application, one may have an advantage over the other. The evolution of both forms, integrated and standalone, has resulted in each offering consistently greater levels of functionality.

There are two basic means of temperature control, regardless of the actual device used. Open loop control delivers a predetermined amount of output action without regard to the process condition. Its simplicity makes open loop control economical. Best applications for this type of control action are processes that are well understood and that can tolerate a potentially wide variation in temperature. A change in the process condition will not be detected, or responded to, by open loop control. The second temperature control method, and the one most employed for industrial process control, is closed loop.

Closed loop control relies on an input that represents the process condition, an algorithm or internal mechanical means to produce an output action related to the process condition, and some type of output device that delivers the output action. Closed loop controllers require less process knowledge on the part of the operator than open loop to regulate temperature. The controllers rely on the internal processing and comparison of input (process temperature) to a setpoint value. The difference between the two is the deviation or error. Generally, a greater error will produce a greater change in the output of the controller, delivering more heating or cooling to the process and driving the process temperature toward the setpoint.

The current product offering for standalone closed loop temperature controllers ranges from very simple on/off regulators to highly developed products with multiple inputs and outputs, as well as many auxiliary functions and communications. The range of product features almost assures a unit is available for every application. Evaluating the staggering range of products available and producing a good match between process requirements and product capabilities can be facilitated by reaching out to a process control products specialist. Combine your own process knowledge and experience with their product application expertise to develop effective solution options.

Diaphragm Seals For Protection of Process and Pressure Instruments

One of many diaphragm seal variants
Courtesy Wika

Pressure measurement is a common element industrial operations or control systems. Fluid processing can often involve media that is potentially harmful to pressure sensing devices. The media may be corrosive to the sensor material, or other media properties may impact the performance or usable life of the instrument. In process control environments, diaphragm seals play a role in protecting items like pressure sensors from damage by process fluids. The diaphragm seal is a flexible membrane that seals across the connecting path to a sensor and isolates the sensor from the process media. System pressure crosses the barrier without inhibition, enabling accurate measurement, but the process fluid does not. Typical materials composing diaphragm seals are elastomers, with a wide variety of specific materials available to accommodate almost every application.

In the operating principle of the diaphragm seal, the sealed chamber created between the diaphragm and the instrument is filled with an appropriate fluid, allowing for the transfer of pressure from the process media to the protected sensor. The seals are attached to the process by threaded, open flange, sanitary, or other connections.  Diaphragm seals are sometimes referred to as chemical seals or gauge guards. Stainless steel, Hastelloy, Monel, Inconel, and titanium are used in high pressure environments, and some materials are known to work better when paired with certain chemicals.

Sanitary processes, such as food, beverage, and pharmaceuticals, use diaphragm seals to prevent the accumulation of process fluid in pressure ports, a possible source of contamination. If such a buildup were to occur, such as milk invading and lodging in a port on a pressure gauge, the resulting contamination compromises the quality and purity of successive batches. Extremely pure process fluids, like ultra-pure water, could be contaminated by the metal surface of a process sensor. Some pneumatic systems rely on the elimination of even the smallest pressure fluctuations, and diaphragm seals prevent those by ensuring the separation of the process materials from the sensors.

Diaphragm seals are not without some application concerns, and devices are now built to address and counter many potential issues related to the use of diaphragm seals with process monitoring instruments and equipment. Products seek to eliminate any and all dead space, allow for continuous process flow, and are self-cleaning thanks to continuous flow design. Some high pressure seals come equipped with anti-clogging features, accomplished by the elimination of internal cavities while protecting gauges. Multi-purpose seals reduce temperature influence and improve instrument performance while pinpointing and diffusing areas of high stress. These pre-emptive measures result in longer instrument life-cycles and improved performance while ensuring protection from corrosion.

There are numerous options and available diaphragm seal variants. Share your application specifics with a product specialist, combining your own process knowledge and experience with their product application expertise to develop an effective solution.

Accurate Level Measurement Contributes to Heat Rate Reduction

Industrial steam turbine

Steam production is a costly operation in any facility, but is of paramount importance in power generation plants. The bottom line of a combustion based power generation facility is sensitive to the cost of input fuel. Measures that can be taken to reduce fuel input for a unit of power output (called heat rate) can translate directly into profitability. An additional benefit of reducing heat rate is a commensurate reduction in emissions.

A major contributor to heat rate reduction is the recovery of heat from the process and transference of that heat into the boiler feedwater. A sizable feedwater preheater of the shell and tube type is used to recover the heat. Shell and tube heat exchanger efficiency can be maximized with accurate control of liquid level.

Magnetrol, globally recognized leader in level measurement technology, makes the case for using guided wave radar level measurement technology as the most advantageous means for this application. The video below describes the process and how the guided wave radar level transmitter can provide the best performance.

Magnetrol has an information kit devoted to heat rate reduction. Share your steam system and level measurement challenges with a product specialist, and ask how you can get the Heat Rate Reduction Kit. Combining your facility and process knowledge with the product application expertise of a specialist will result in effective solutions.

Thermal Mass Flow Meter Q&A From Magnetrol

Thermatel® thermal mass flow meter
Courtesy Magnetrol®

Sometimes you discover that others do something better than you. When that happens, watch and listen.

Tom Kemme, from Magnetrol®, expertly fielded some questions about thermal mass flow meters in a recent blog post. Mr. Kemme's responses were so useful and clear that I decided, with all the credit flowing his way, to share them here for those of you that may not closely follow the Magnetrol® Blog.

Question: What is the difference between the flow units Nm3/h, Sm3/h, and actual m3/h?

Answer: Actual m3/h is a flow rate at operating temperature and pressure. Normal or standard m3/h (Nm3/h = Sm3/h) is a flow rate at standard temperature and pressure (STP). I tend to reference the natural gas industry, where it is not possible to compare flow rates at every operating condition, so it is preferable to reference all flow rates back to a set of base conditions, such as 60°F and 1 atm. STP is not universal so it may be unique based on the region or industry.

Most flow meters output a flow rate at operating conditions and need to correct this measurement. This may be accomplished with a multivariable transmitter or external to the device. A few examples that do not need to correct the measurement are thermal mass flow meters, such as the ones produced by MAGNETROL, and Coriolis flow meters.

Question: Do you have any certified failure rate data on your units to perform an SIL verification?

Answer: A Failure Modes, Effects, and Diagnostics Analysis (FMEDA) is completed during development to determine failure rates and Safe Failure Fraction (SFF). The SFF is utilized to determine Safety Integrity Level (SIL), which is often the published value.

Question: What should my meter be reading with no air flow in the pipe?

Answer: At zero flow and a dry pipe, a thermal mass flow meter should measure zero. Different thermal meters may have varying stability at no flow due to differences in operation.

There are two different types of operation: constant temperature (CT) and constant power (CP). CT devices start with a low power and this power increases with the flow rate to maintain the constant temperature difference (ΔT) between the RTDs. CP devices start with a high ΔT between RTDs at low flow and the ΔT decreases as the flow rate increases. CP may lack stability at zero flow due to possible convection currents associated with the high ΔT. CT will hold zero better, particularly devices that add less heat. For example, the maximum surface temperature of a TA2 probe is 4 C above process temperature. This is extremely low heat, eliminating convection currents due to the sensor. Convection currents could also occur through the pipe due to temperature variations.

It is also possible for a thermal meter to measure above zero during a no flow condition when there is pressure buildup in the line (typically a valve closed downstream). There may be low flow cutoff settings that can be changed to ignore nuisance measurements.

You can easily tap into Magnetrol® expertise to solve your flow measurement challenges. Reach out to a product specialist and combine your process knowledge with their flow measurement expertise to develop effective solutions.

Mounting Options For DP Transmitters With Universal Mounting Bracket

This short video illustrates the ease with which numerous mounting configurations of DPharp transmitters can be accomplished in new and existing operations. The DPharp line of pressure transmitters utilize Yokogawa's top flight digital sensing technology for accurate process measurement of pressure and differential pressure in a multitude of applications.

Share your process measurement challenges with application experts, combining your process knowledge with their product application expertise to develop effective solutions.