Level Measurement: Comparing Displacer Transmitters and Differential Pressure Transmitters

Electronic Displacer Transmitter
Courtesy Magnetrol

Liquid level measurement is ubiquitous throughout industrial fluid processing operations. Whether via direct or inferential means, the fluid level data point is an integral part of operational and safety plans for an installation.

Magnetrol, a globally recognized leader in the design and manufacture of level measurement instrumentation, has produced a comparison of displacer transmitters and differential pressure transmitters applied to liquid level measurement.

What is a displacer transmitter?

Displacer transmitters are considered a direct means of level measurement.

Quoted from Magnetrol website page on displacer transmitters...

Electronic displacer level transmitter technology operates by detecting changes in buoyancy force caused by liquid level change. These forces act upon the spring supported displacer causing vertical motion of the core within a linear variable differential transformer.
As the core position changes with liquid level, voltages are induced across the secondary windings of the LVDT. These signals are processed in the electronic circuitry and used to control the current in the 4-20 mA current loop. The enclosing tube acts as a static isolation barrier between the LVDT and the process media.

 How does a differential pressure transmitter measure liquid level?

Liquid level can be inferred through the measure of the pressure generated by the column of liquid in a tank or vessel. The measurement device must be calibrated for the specific gravity of the measured media in order to attain reasonably accurate results. There are a number of installation arrangements of differential pressure transmitters that will accommodate tanks open to atmosphere, closed pressurized tanks, and more.

The comparison is included below and provides some interesting points to consider. Share your level measurement application challenges with a product application specialist. Combining your process experience and knowledge with their product application expertise will produce the best solutions for your process measurement needs.

Comparing Level Measurement Methods: Displacment Transmitter vs Differential Pressure Transmitter from MSJacobs-Cali

SVF Flow Controls Explains Surface Roughness for Valves Intended for Special Applications

Vales utillized in industrial processes
can require special materials or finishes.

Fluid control operations can sometimes require special materials of construction or finishes for piping and specialties, like valves. A segment of the industrial valve manufacturing sector specializes in providing fluid control valves with coatings, surface finish, and materials of construction suitable for the requirements of applications not well serviced by more common constructions.

One manufacturer, SVF Flow Controls, has published a short article explaining some of the basics about surface finish. The article defines surface finish and goes on to describe some of the methods employed to achieve various levels of surface roughness and texture. The article, included below in its entirety, is short and informative.

Share your specialty valve applications with product experts. The combination of your process expertise and their product knowledge will produce the most effective solutions.

Surface Roughness in Metal Finishing from MSJacobs-Cali

High Density Signal Conditioning Modules Offer Bluetooth® Configuration of I/O Ranges and Alarms

The microBlox™ signal conditioners for high density I/O configuration

Acromag, a globally recognized manufacturer of signal conditioning modules and related equipment, announced a new product release earlier this month. The microBlox™ line of signal conditioners provides a wide array of useful features, broad range of I/O signal compatibility, and a very compact high density footprint.

Here is an excerpt from the Acromag newsletter from June 6, 2016.

A full line of microBlox™ isolated signal conditioning modules are now available from Acromag. Offering over 175 models, microBlox uB modules can safely interface a wide variety of voltage, current, temperature, frequency, and other field signals with a ±5V or 0-5V DC output to host measurement & control systems. Users can select modules with fixed ranges or wireless configuration via Bluetooth® wireless technology on an Android™ or iOS® mobile device. Acromag’s free AgilityTM app for smartphones and tablets simplifies setting custom I/O ranges and optional alarm functions. The app can also display input signal values and create sharable trend charts. uB modules snap securely into compact backpanels (no screws) in any mix with 4, 8 or 16-channel capacities. With 1500Vac peak (350Vdc continuous) channel-to-channel and field-to-host isolation, the hot-swappable modules are ideal to front-end data acquisition systems or Acromag remote I/O for communication to Ethernet, Modbus, or Profibus networks. High performance is assured with up to 0.05% accuracy and 130dB noise rejection. Prices start at just $90 per module. 

“Advanced microcontroller and wireless technologies enable microBlox modules to bring greater flexibility and signal processing capabilities into such a small, economical package.” stated Robert Greenfield, Acromag’s marketing & sales director.
The microBlox module’s small size (1.11" x 1.65" x 0.4") and channel-by-channel scalability is ideal for embedded or portable applications such as test stands, defense systems, and process control applications. Well-suited for use in harsh industrial environments, the over-molded modules resist shock, dirt, and moisture with dependable operation from -40 to 85°C. Hazardous location UL/cUL Class 1 Div 2 and ATEX Zone 2 approvals are also available.

Accessories include a selection of backpanels with slots to insert 4, 8, or 16 modules. Fuse clips hold the modules securely without screws for easy insertion/removal. The backpanels support surface or DIN rail mounting and include CJC for use with temperature input modules. Blue LEDs indicate modules that are ready for Bluetooth wireless technology communication. Connections are provided for a 5V power source or a 10-32Vdc supply when used with the plug-in 5V power module. A DB25 header facilitates a single cable connection to interface all uB I/O signals directly to the host data acquisition system.

 A consolidated catalog describing the new microBlox™  signal conditioners is included below. Share your signal conditioning and I/O challenges with a a product specialist. Combining your process knowledge with their product application expertise will produce the best solutions.

High Density Signal Conditioners From Acromag from MSJacobs-Cali

MS Jacobs & Associates Offers Line of Corrosion Resistant Industrial Fluid Handling Process Control Equipment

TKS/TKP/TKM Series PVC + PP Paddle Wheel Flow Meters

Courtesy Icon Process Controls Ltd.

MS Jacobs & Associates now represents ICON Process Controls in Pennsylvania, New York, and West Virginia. ICON specializes in corrosion resistant industrial fluid handling process control equipment, offering industry the most complete line of all plastic instrumentation products supported by the largest inventory in North America. Markets include Municipal and Industrial Water & Waste-Water Treatment, Bulk Chemicals, Steel Processing, Metal Finishing, Chemical Dosing Skids, and Food & Beverage.

The company's products complement and expand MS Jacobs' already extensive array of process measurement and control instruments and equipment. The ICON line includes devices for measuring and controlling flow, level, pressure, and temperature. Their unique all plastic construction makes the ICON equipment and instruments particularly well suited to the harshest industrial environments.

For information about the complete line of corrosion resistant industrial fluid handling process control equipment from ICON, reach out to the process control experts at MS Jacobs. Share you process control challenges and combine your process knowledge with their product application expertise to formulate the best solutions.

Building Steam System Efficiency for Profitable Returns

Improvements in steam system efficiency can yield
substantial return on investment

Steam, an energy efficient, reliable, scalable form of transferring heat, is utilized throughout commercial, industrial, and institutional settings. The ubiquitous adoption and use of this heat transfer medium has resulted in steam generation ranking as a substantial line item on any organization's financial operating report. The scale of many steam production operations can produce some sizable payback opportunities from modifications that improve efficiency or reduce maintenance requirements.

The application of modern precision measurement instrumentation is one area where comparatively modest investments in system improvement can yield ongoing returns. Magnetrol International, a globally recognized leader in the design and manufacture of flow and level instrumentation, has produced a white paper describing aspects of the steam cycle that are candidates for profitable improvement and how various measurement technologies can help garner the maximum attainable gain in efficiency.

The paper is included below, and will prove to be informative and interesting reading. More information is available on specific instrument recommendations from product application specialists. Share your steam system challenges with them and work together to find the best solutions.

Optimizing the Steam Generation Cycle and Condensate Recovery Process from MSJacobs-Cali

Multivariable Flow Meter Provides Pressure, Temperature, Flow Measurements

Multi-Variable Flowmeter
AX Series
Courtesy Azbil N.A.

M.S. Jacobs includes the Azbil North America line of process measurement and control products in its offering. One of Azbil's flagship products is the AX series of multivariable vortex flowmeters for industrial process measurement and control. The instrument combines temperature, pressure and velocity measurement in a single instrument to provide accurate mass flow measurement of gases, liquids and steam.

When compared to arrangements with discrete instruments for each variable, incorporating several variable measurements into a single package reduces potential leakage points, installation complexity, and space requirements . Configurations for in-line or insertion installation are available for line sizes ranging from ½” to 8” for in-line and 2” and greater for insertion. A sizing guide, application and product configuration assistance is available from the product specialists at MS Jacobs.

Multivariable Flowmeters for Process Measurement & Control from MSJacobs-Cali

Positive Returns From Steam Generation and Condensate Recovery Efficiency Gain

Steam systems are excellent candidates for cost saving
through increased efficiency.

The generation of steam is a lifeblood operation to many commercial and industrial operations around the world. The large scale of its use can make steam generation one of the largest energy consumption activities for an industrial plant or commercial building. The size and complexity of steam systems, with generation, condensate handling, heat recovery, and feedwater treatment, provides a number of areas where inefficiencies can cost very substantial sums of money. Conversely, enhancing efficiency toward a maximum attainable level will yield very large savings in operating costs.

Magnetrol International, a globally recognized leader in the design and production of flow and level controls for commercial and industrial use, has produced a video summarizing the elements of the steam system that are good candidates for upgrade, as well as general direction on how to achieve increased efficiency for each. In keeping with the company's line of level and flow measurement products, the focus is on how accurate and robust instrumentation can improve overall system performance and generate a decidedly positive return on the time and funds invested.

Invest a few minutes in the video below and learn how the operating efficiency of your steam system can be elevated with an instrument upgrade. There is a white paper on the same subject available on request. You can also receive a listing of the specific Magnetrol instruments that can be applied to steam systems, with a short description of where each is applied. Reach out to a product application specialist and share your steam system challenges. Combining your system knowledge with their product application expertise will yield the best solution.

Radar Level Transmitter Crosses Competitive Price Level

Magnetrol Model R82 Radar Level Transmitter

With its ability to reliably detect tank liquid surface level under conditions that prove challenging to other methods, radar technology generally provides an operational advantage over other non-contact level measurement options. Historically, the cost of radar level transmitters for industrial process control applications has hindered their success as a unit of choice for some installations. Magnetrol has changed that imbalance with their recent introduction of a lower cost radar level transmitter for tough applications.

The Model R82 provides radar performance at a price point comparable to competitive ultrasonic units, but maintains the performance advantage inherent in a radar based device. The unit utilizes pulse burst radar technology at 26 GHz, employing advanced signal processing to filter out false echos produced by a range of in-tank conditions that can produce false readings from ultrasonic units.

The short video below provides a closer look at the R82 and its performance advantages. Technical data sheets and any application assistance you may need is available from product specialists. Share your level measurement and control challenges with them and work toward the best solution.

Understanding Instrument Valves

Gauge Root Valve, a type of
instrument valve
Courtesy Mac-Weld

Process measurement and control employs a wide array of gauges and instruments that may be permanently or temporarily connected to a piping system. Providing controlled isolation and connection of these instruments is the function of what are generically referred to as "instrument valves" or "gauge valves". These valves are generally small, with connection sizes ranging from 1/8" to 1", though there are specialty variants outside this range. The predominant valve type is a needle valve, but ball valves and some other types are also used. Certain attributes of particular applications may weight a selection decision toward a valve type. Widely used throughout the process industries, instrument valves are often designed to accommodate pressures as high as 6000 PSI and are intended for service with gaseous or liquid service.

When selecting an instrument valve, consider construction materials that are compatible with the process media. Additionally, operating temperature and pressure of the process must be well within the limits of the valve.

Instrument needle valves provide reliable function to throttle, regulate and isolate gaseous and aggressive non-viscous liquid services. Product offerings range from simple two-way isolation valves to multiport gauge root valves providing multifunction capability to isolate, calibrate and vent gauge, pressure switches and static instrument applications. Ball valves in this class do not provide the throttling accuracy of a needle valve, but may provide some advantage with the use of certain media. The ball valve design, with its full size port, enables easier cleaning and a lessened potential for clogging.

There are three basic configurations of instrument valves. The simplest is the isolation valve with a single inlet and outlet. It provides for selection of exposure or isolation of a connected gauge or other device to the operating process piping or vessel. Maintenance or replacement of the connected device can be effected without opening the contained process to the surrounding environment.

Schematic representation of isolation valve

A second variant of instrument valves performs the function of an isolation valve, but has an added port on the outlet side (the side where a gauge or instrument would be connected). The added function of the port is to provide connection access for service, calibration, sampling, purging, or a host of other tasks, all of which can be completed while the process remains in operation.

Schematic representation of block and bleed valve

The third form of instrument valve is a multi-port valve with a single inlet and three outlets. It is often called a "gauge root valve" and serves a number of purposes with its multiple outlet connections. Sometimes two of the ports will be plugged and the instrument or gauge connected to the port providing the most convenient or functional orientation of the connected gauge or the valve handle. This valve can also enable a wide variety of applications through connection of additional instruments, gauges, valves, or other equipment.

Schematic representation of gauge root valve

Share your process measurement and control instrumentation and gauge challenges with application experts and benefit from their expertise.