Magnetrol® Instruments With SIL Certification: Protecting Your Plant

In the process control industries, safety and reliability are paramount. Operators are searching for the peace of mind that comes from high-quality instruments. To minimize risks, the Safety Integrity Levels, or SIL, were developed as an integral part of a comprehensive safety system. SIL certification and SIL ratings guarantee a level of dependability and security that operators can trust.

Many Magnetrol® products are SIL-suitable. Below is some more information about the transmitters and switches that are SIL-Suitable or have received SIL certification:

SIL-Suitable Switches

Echotel® Model 961 Single Point Ultrasonic Level Switches
Reliable single point level measurement. Advanced self-testing continuously monitors the electronics, transducer and piezoelectric crystals. An adjustable time delay is provided for reliable measurement in turbulent processes. Rated SIL 2 FMEDA.

ultrasonic level switches

Echotel® 961 and 962 ultrasonic level switches

ECHOTEL Model 962 Dual Point Ultrasonic Level Switches
Reliable dual point level measurement or pump control. A tip sensitive lower gap allows measurement to within 1⁄4″ of the vessel bottom. The flow-through upper gap allows up to a 125″ (318 cm) separation between switch points. Rated SIL 2 FMEDA.

Single-stage External Cage Float Level Switches
Field-proven switches. Self-contained units designed for external mounting on the side of a vessel, tank or bridle. Over 30 models of mechanical switches have proven their reliability and repeatability for decades in numerous applications. Rated SIL 2 FMEDA.

Single-stage Displacer Level Switches
Ideal for sumps, storage and process vessels. Models A10, A15 and External Caged Displacer Switches offer flexibility in application and are not affected by dirty liquids, coating foam, turbulence or agitation. Rated SIL 2 FMEDA.

Thermatel® TD Series Flow, Level Interface Switches
Reliable operation for flow, level, or interface detection. Offer continuous self-diagnostics. Temperature compensation provides repeatable switch operation with varying process temperature. Gas or liquid flow applications. Rated SIL 1 FMEDA.

THERMATEL TG Series Flow, Level Interface Switches
Suitable for liquid or gas flow, level, or interface detection. Provide a two-wire intrinsically safe circuit between the probe and remote DIN rail enclosure. 24 VDC input power, relay plus mA signal for flow trending/indication. Rated SIL 1 FMEDA.

SIL-Certified Transmitters

Eclipse® Model 706 Guided Wave Radar Level Transmitter
The leader in high-performance guided wave radar. This 24 VDC loop-powered transmitter utilizes a variety of coaxial, twin, and single-rod probes. Performance is not process dependent, and it is capable of measuring low dielectric liquids or solids. Rated SIL 2/3 Certified.

ECLIPSE Model 705 Guided Wave Radar Level Transmitter
Provides measurement performance well beyond that of many traditional technologies. This 24 VDC loop-powered transmitter utilizes coaxial, twin, and single-rod probes. Performance is not process dependent. Rated SIL 2/3 Certified.

E3 Modulevel® Displacer Level Transmitter
Takes displacer transmitters to the next level. Set up in as few as two steps without level movement. Microprocessor-based, HART, AMS and PACTware™ compatible, E3 offers stable, reliable 4-20 mA output in most applications. Rated SIL 2 FMEDA.

SIL-Suitable Transmitters

Jupiter® Magnetostrictive Level Transmitter
Available in single and dual float models. A loop-powered level transmitter with HART communications, PACTware™ DTM interface, LCD display and push button configuration. It may be externally mounted to a MLI or directly into a vessel. Rated SIL 2 FMEDA.

TA2 Thermal Mass Flow Meter
Provides reliable flow measurement of air and gases. Delivers excellent low flow sensitivity, high turndown and low pressure drop. Pre-calibrated and configured for the user’s application. Integral or remote electronics. Rated SIL 1 FMEDA.

More Information
To learn more about MAGNETROL products and their SIL certification, visit

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Level Solutions for Chemical Industry Reboilers

Reboilers, or vaporizers, are heat exchangers that provide heat to the bottom of a distillation tower. They boil the bottom liquid to generate vapors which are returned to the tower to drive the distillation separation process. The reboiler may partially or completely vaporize the stream it receives from the bottom of the tower. Proper reboiler operation is crucial for distillation to be effective, and high-quality level instrumentation can ensure reboilers function correctly.

Magnetrol® has produced a brochure detailing different applications throughout the reboilerschemical industry and exploring measurement challenges and solutions for each one. This blog post is part of an occasional series exploring each application in detail.

Level Measurement Challenges and Considerations

Excess reboiler liquids (bottoms or blow-down) overflow a baffle where level is controlled by means of a level controller. If the reboiler level becomes too low, it will affect the maximum flow rate of bottoms product that can be drawn off. Inaccurate reboiler level can also degrade composition control for material balance control configurations.

Level Instrument Solutions

MAGNETROL offers a range of level instrumentation solutions for reboilers:

  • For point level measurement
    Series 3 float-activated external cage level switch or Tuffy® II float-actuated switch
  • For continuous level measurement
    Eclipse® Model 706 guided wave radar transmitter or E3 Modulevel® displacer-actuated transmitter
  • For visual indication
    Atlas™ or Aurora® magnetic level indicators can be supplied with switches or transmitters

More Information

For more information on level measurement solutions for reboilers and other chemical industry applications, download the Chemical Industry brochure.

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Thermal Mass Flow Meter Monitors Methane Emissions

As the EPA works towards additional methane regulations, the emphasis on compressor emissions will increase. Methane is a greenhouse gas with over 20x the global warming potential as carbon dioxide. Technologies must progress to ensure oil & gas companies meet the growing requirements of regulatory committees and monitor their methane emissions accurately.

Gas Flow Measurement Challenges

methane emissions

Magnetrol® Thermatel® TA2 with flow body (spool piece) measuring natural gas.

A leading oil & gas company required a gas flow measurement technology that could accurately measure natural gas flow rates at their compressor stations. One of the applications of interest was measuring vent gas emissions from the packing systems of compressors. This application not only required flow measurement at very low flows and low pressures, but the capability of achieving high turndown as well. Emissions can tend to increase over time as components wear, thus increasing the potential flow rates. Any instrument measuring these flow rates would need to be able to track any potential increases.

Flow Meter Solutions for Monitoring Methane Emissions

Magnetrol® produces a thermal mass flow meter, the Thermatel® Model TA2, that is based on thermal dispersion technology. The TA2 measures air and gas flow directly and has excellent low flow sensitivity, as well as high turndown ratios. Turndown is the range that the flow meter is accurate within. Most thermal mass flow meters offer 100:1 turndown, which is a drastic improvement over most technologies such as differential pressure, but certain applications demand greater. This presented an improvement opportunity for the TA2.

Since the TA2 is capable of holding multiple calibration curves, users requested added functionality of these features. To meet this need, MAGNETROL developed auto switching to fully utilize two distinct calibration curves. Auto switching will automatically alternate between a low flow curve and a high flow curve to maximize data in the customer flow range and extend the turndown. This ensures optimal performance at both low flows and the abrupt high flow (upset) condition or an increase in flow over time due to degradation of components. Plants can trust that the methane emissions levels they report are accurate because the TA2 is able to measure low and high flow rates with precision.

More Information

To learn more about how thermal mass flow meters can monitor a wide range of applications efficiently and safely, visit

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Frequently Asked Questions About Ultrasonic Level Switches

Ultrasonic level switches use high-frequency sound waves that are easily transmitted across a transducer gap in the presence of a liquid media, but are attenuated when the gap is dry. The Magnetrol® ultrasonic portal,, provides information about the Echotel® series of ultrasonic switches and how they can improve the safety and efficiency of many processes. Periodically, MAGNETROL product manager Tom Kemme answers questions about ultrasonic level switches in the portal’s “Ask Tom” column. This week’s blog post shares some recent Q&As.

ultrasonic level switches

Echotel® ultrasonic level switches

Question: Can ECHOTEL be used in applications that have entrained air?

Answer: Yes, ECHOTEL ultrasonic switches can be used in applications that have entrained air. All ECHOTEL gap switches feature a tip-sensitive transducer that provides superior performance over side gap transducers that are offered by other companies. Side gap transducers allow gas bubbles to adhere to the upper surface of the gap, which cause false dry gap alarms. Tip sensitive transducers allow these bubbles to pass through the gap. Applications with severe turbulence or entrained air should use the Model 961 switch, which offers a time delay adjustment. Up to 10 seconds of delay can be used to disregard entrained air and reliably detect the true liquid level.

Question: We are considering adding level alarm switches to our process to provide high-high level indication in several tanks. Instead of switches with relay outputs, we are considering the current shift output. What are the advantages of a current shift output?

Answer: Current shift electronics simply shift the current output from 8 mA when the level switch is in the normal operation, to 16 mA to indicate a level alarm. ECHOTEL Model 961 also has a user selectable fault signal of 3.6 or 22 mA. Current shift switches are 2-wire loop powered, which allows them to be offered with intrinsically safe approvals. This allows these switches to be put into hazardous area locations at a lower cost since rigid conduit is not necessary. Since current shift switches provide constant indication of either a normal (8 mA), alarm (16 mA), or a fault (3.6 or 22 mA) condition, they are sometimes referred to as a transmitter for the price of a switch.

More Information

To learn more about the advantages of ECHOTEL ultrasonic level switches, or to ask a question of your own, visit

ultrasonic level measurement 2

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Driving Down Fuel Costs With Feedwater Heater Level Control

For most power plants, 70 to 80% of their production costs are fuel expenses. Hence, any improvement in fuel efficiency can have a significant impact on a plant’s profitability. By improving final feedwater heater temperature through better feedwater heater level control, plants can reduce heat rate and realize significant cost savings. For instance, in a 500-megawatt power plant, improving heat rate by 1% could generate $500,000 in annual savings.

Heat rate is a measure of how efficiently a plant uses heat energy. The higher the heat rate, the less efficient the plant. Heat rate has a major impact on a company’s bottom line and its ability to compete in unregulated markets. The benefits of an improved heat rate go well beyond consumption and cost. A plant can see a reduction in emissions by simply reducing the amount of fuel required to generate a given amount of energy. In many cases this can be accomplished in a cost-effective manner by improving feedwater heater level control. Reducing heat rate also increases boiler longevity by eliminating overfiring. And there is significant public relations value when a plant shows itself to be taking all possible steps to minimize its impact on the environment.

Level Control Throughout the Power Cycle
Maintaining accurate, reliable level control throughout the power cycle is critical. The condenser is the beginning of the feedwater heater process, where condensed steam from feedwater heater drains and HP, IP, and LP turbines is routed through successive feedwater heaters. At the same time, extraction steam from turbines reaches the appropriate feedwater heaters and the transfer of energy takes place. Reliable, accurate level control is critical to achieving the final temperatures that this cycle requires.

feedwater heater level controlFeedwater Heater Operation
Feedwater heaters use the heat of condensation to preheat water to the correct temperature for the boiler. During this process, shell and tube heat exchangers allow feedwater to pass through the tube side and extract water from the turbine to the shell side. When controlled properly, feedwater heaters can decrease fuel costs by using extraction steam to preheat water rather than costly hot fuel. Achieving optimum water level in the feedwater heater reduces heat rate and lowers fuel costs. Making an investment in level control can help you achieve optimum heat.

Instrumentation for Feedwater Heater Level Control
The Eclipse® Model 706, a guided wave radar transmitter produced by Magnetrol®, is a smart choice for monitoring feedwater heater level control. The ECLIPSE 706 guided wave radar (GWR) transmitter can help plant operators optimize the condensing zone, deliver accurate level control, maximize energy transfer, and minimize undue wear and tear.

While older level technologies, such as differential pressure, magnetostrictive, RF capacitance, and torque tubes are often used to measure feedwater heater level, these instruments can cause issues for power plant operators. Older technologies such as these are vulnerable to process conditions, induced instrument errors, shifts in specific gravity and mechanical or electronic drift.

GWR is the truly reliable measurement solution for feedwater heater level control, because it is unaffected by process conditions, requires no calibration or gravity corrections, and has superior signal-to-noise ratio. Using a guided wave radar transmitter like the ECLIPSE Model 706 can help power plants achieve a reduced heat rate and lower fuel costs.

More Information
To learn more about feedwater heater level control, and to download a kit about managing your heat rate, visit


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Level Measurement Solutions for Chemical Distillation Towers

Separation and purification is a crucial part of all industrial operations that deal with chemicals. Selecting a separation technology from among 20 leading varieties depends upon a chemical’s nature, the number of phases, and the capacity, speed and efficiency required. Distillation—separating substances based on differences in volatilities—is the most widely used separation and purification method. Today, approximately 40,000 distillation towers are operating in U.S. chemical plants.

Magnetrol® has produced a brochure detailing different applications throughout the distillation towerschemical industry and exploring measurement challenges and solutions for each one. This blog post is part of an occasional series exploring each application in detail.

Level Measurement Challenges and Considerations
Distillation is an energy-intensive process—in a typical chemical plant, it accounts for about 40% of the total energy consumption. Reliable level measurement is needed in order to maintain energy efficiency throughout the distillation process and lower the fuel costs needed to distill. In addition, level measurement at the bottom of a distillation tower controls the “bottoms” product rate. Poor high level control could allow liquid to back up over the stripping trays causing damage and reduced yields. Too low of a level may cause pump cavitation. In related extraction and distillation towers, interface level control provides optimal separation from associated substances.

Level Instrumentation Solutions
MAGNETROL offers a range of level instrumentation solutions for chemical extraction and distillation towers:

  • For point level measurement
    Series 3 float-actuated external cage level switch
  • For continuous level measurement
    Eclipse® Model 706 guided wave radar transmitter or E3 Modulevel® displacer-actuated transmitter
  • For visual indication
    Atlas™ or Aurora® Magnetic Level Indicators can be supplied with switches or transmitters

More Information
For more information on level measurement solutions for distillation towers and other chemical industry applications, download the Chemical Industry brochure.


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Answers to Key Measurement Questions About Thermal Mass Flow Meters

The Magnetrol® flow portal,, provides information about thermal mass flow meters and how they can improve the efficiency and safety of many processes. Periodically, MAGNETROL product manager Tom Kemme answers questions about flow meters in the portal’s Ask the Expert column. This week’s blog shares some recent Q&As.

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

thermal mass flow meters

Magnetrol® expert Tom Kemme answers your questions.

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.

More Information

For more information about thermal mass flow meters, or to ask a question of your own, visit


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Happy New Year From Magnetrol!

happy new year

All of us at Magnetrol® wish you a happy and successful 2017! Thanks for being part of making our 2016 great.

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Happy Holidays From Magnetrol

happy holidays

Magnetrol® would like to wish you all a safe and happy holiday season! May you find peace and joy during this special time of year.

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Level and Flow Measurement for Water and Wastewater Treatment Plants

In a world more focused than ever on safe, sustainable stewardship of our water resources, it is critical to continue to improve the ways in which we measure and treat potable water and wastewater. Increased public awareness drives the need for safe, accurate and reliable level and flow instrumentation, in the harshest environments, under the most extreme conditions. At the same time, the regulatory climate requires plants to implement next-generation process improvement – moving from energy efficiency to energy independence and realizing cost-savings in doing so. Innovations in level and flow control can help water and wastewater treatment plants manage energy usage and monitor applications more effectively.

wastewater treatment plants

A Polaris® electromagnetic flow meter

Magnetrol® offers a wide range of instrumentation for water and wastewater applications, designed to monitor level, flow and volume at every step of the treatment process. Below are a few of the instruments that can help you better manage your treatment plant.

Pulse Burst Radar

The MAGNETROL Model R82 pulse burst radar transmitter provides radar-reliable process measurement in challenging, vapor-saturated environments. It is inexpensive enough to be used in place of ultrasonic transmitters, making it a cost-effective choice.

In a water treatment plant, the R82 can provide continuous level measurement for:

  • lift station and coagulant feed tanks
  • settling tanks during clarification
  • polymer, filter, and lime slurry tanks during filtration
  • open atmospheric water reservoirs where control technology must withstand weather conditions

The R82 is also a reliable option for wastewater treatment plants, where it can:

  • control level at lift station pump, open channel flow and screening system
  • monitor feed tanks containing chemical coagulants, oxidants and phosphorus precipitations
  • measure splitter box and clarifier levels
  • control corrosion inhibitors
  • manage PH adjustment, mixed liquor and secondary clarifier levels
  • provide activated sludge and digester level control

Thermal Dispersion Mass Flow Meters

Flow measurement plays a vital role in efficiently managing water quality processes and regulatory reporting protocol. MAGNETROL produces the Thermatel® Model TA2 thermal dispersion mass flow meter to monitor these applications. The THERMATEL TA2 offers outstanding accuracy and reliability, as well as the ability to maintain a strong signal at low flow rates and pressure over a wide operating flow range.

The THERMATEL TA2 is ideal for wastewater operations due to its low flow sensitivity, wide temperature operation and high turndown capabilities. It can manage efficient blower airflow to optimize breakdown of waste and reduce blower costs. The THERMATEL TA2 also offers exceptional safety and accuracy for digester gas flow measurement.

Electromagnetic Flow Meters

The Polaris® electromagnetic flow meter, produced by MAGNETROL, offers flow monitoring that can help maintain efficient water and wastewater operations. POLARIS flow meters can measure forward and reverse flow rates through the capability of empty pipe detection. Closed pipe flow control is a widespread application for POLARIS throughout water treatment plants. In wastewater treatment facilities, POLARIS flow meters provide efficient water and sludge flow control. The flow meters have current, pulse and alarm outputs that are configurable through the display or a device type manager, making POLARIS a flexible choice for flow control.

More Information

These are just a few of the options MAGNETROL offers for water and wastewater process instrumentation. For more information on level, flow and volume control for water and wastewater treatment plants, please visit

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