Friday, May 31, 2019

Electromagnetic Flowmeters and Dual Frequency Excitation

Magnetic flowmeter
The electromagnetic flowmeter, commonly known as the "magmeter", gets its name from the magnetic field generated within the float tube that produces a signal proportional to flow. This principle employs Faraday's Law of Electromagnetic Induction. Magnetic flowmeters are built so the direction of the magnetic field is perpendicular to the flow and the line between the electrodes is also perpendicular to the flow. As a conductive liquid flows through the flowtube, an electro-motive force is generated. The electrodes detect the electro-motive force. The electro-motive force is proportional to the flow velocity, flux density, and the meter inner diameter. The flux density of the magnetic field and the meters inner diameter are constant values, therefore the magnetic flow meter can calculate the flow velocity and volumetric flow from the electro-motive force.

The basic components of the magnetic flow meter body are:
  • A lined flowtube (typically Teflon)
  • Excitation coils
  • Two electrodes mounted opposite of each other within the flowtube.
Current is applied to the coils in the magmeter to generate a magnetic field within the flow tube. As a conductive fluid flows through the meter, an electro-motiveforce is generated. This force is detected by the electrodes and the resulting value is converted to flowrate.

When magnetic flow meters were originally designed over 50 years ago, they utilized AC type excitation. AC powered magnetic flow meters use line frequency to generate the magnetic field. The frequency of AC excitation is typically 50 to 60 Hertz. This type of excitation has a very fast response time, making it suitable for slurry applications. The weakness of AC type excitation is that it has an unstable zero, and the accuracy is a percent of span, as opposed to a more accurate percent of reading. Because this type of excitation uses line frequency, the power consumption is also very high, making this an expensive meter to operate.

AC and DC excitation
Dual AC and DC excitation
In an effort to improve accuracy and reduce energy cost, pulsed DC type excitation was introduced several years later. The average excitation frequency is between three to eight Hertz, but can go as high as thirty Hertz. The major benefits of pulsed DC excitation over AC excitation is the improved accuracy and zero stability. The accuracy of a DC type meter is a percent of reading. This gives you a more accurate measurement throughout the entire measuring range. Unfortunately, because of the low frequency, the response time is very slow, making it a poor choice for noisy applications.

To overcome the disadvantages of the standard AC and DC excitation methods, and keep the advantage of a high signal-to-noise ratio, Yokogawa's patented dual frequency excitation is the ideal combination. Dual frequency excitation combines the positive benefits of both AC and DC excitation, using both a high 75 Hertz frequency, and a low frequency excitation of approximately six Hertz to drive the coils. Dual frequency excitation is an innovative method that superimposes high frequencies on low frequencies, and utilizes the advantages of each, while eliminating the previously discussed disadvantages. The combination of these methods results in the flow noise immunity and fast response of the high frequency excitation method, and the high zero stability of the low frequency excitation method simultaneously.

For more information on Fike products and capabilities, contact Flow-Tech, Inc. by calling 410-666-3200 in Maryland or 804-752-3450 in Virginia. Or, stop by the website at

Saturday, May 18, 2019

Demonstration of Techniques Used to Mitigate Industrial Explosions and Overpressure Situations

There’s a number of different things that happen with an overpressure event or explosion at an industrial facility. Some are minor. Some are catastrophic. Improved industrial safety can start with something as small as paying careful attention to a speck of dust. Fike’s Combustion Test Lab offers comprehensive explosibility dust testing, providing invaluable data that ultimately helps protect lives and assets.

In August of 2018 an international audience of students, professors and other experts came together at the International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions (ISHPMIE).  Fike Corporation, recognized globally as the most trusted producer of risk mitigation products, presented innovations and solutions at the Combustion Test Lab. This video highlights the demonstrations where a wide variety of overpressure and explosive situations were neutralized using specialized Fike equipment.

The kinds of events that were demonstrated were:
  • Open Air Deflagration
  • Explosion Venting (far right side of screen)
  • Flameless Venting (Fike's Flamquench product)
  • High Rate Discharge (Fike's HRD explosion suppression product)
  • Explosion Suppression (yellow cube with clear panes)
  • Active Isolation (Chemical and Mechanical)
  • Passive Isolation
  • Pressure Relief (featuring Fike's RD500 Atlas rupture disc)
  • Dust Collector Strength-of-Enclosure Test
  • Active Conveyance
  • Metal Dust Deflagration
For more information on Fike products and capabilities, contact Flow-Tech, Inc. by calling 410-666-3200 in Maryland or 804-752-3450 in Virginia. Or, stop by the website at

Tuesday, May 7, 2019

Steam Use Measurement Presents Unique Challenges for Colleges and Universities

Steam poses a unique challenge for colleges and universities.

Many schools want to accurately track, and then internally bill, for steam usage in each of their buildings as part of a wider effort to improve resource management. However, traditional steam metering technologies tend to be a less than optimal choice.

Most times, it’s necessary to place campus steam meters in the basements of buildings where there isn’t a lot of room for piping. That causes issues because flow meters typically require significant runs of straight pipe upstream and downstream of the meter to work correctly.

School administrators also encounter issues by trying to measure steam usage during the low-demand summer months. Common vortex meters, which contain a shedder bar mounted across the diameter of a pipe to measure flow, work well at higher flows. When it comes to low flows, however, they can stop working completely (i.e., low flow cutoff problems). Differential pressure (DP) flow meters coupled with the proper electronics, by comparison, can push the low flow cutoff value downward. However, most DP meters can’t get around the straight-run requirements.
ExactSteam™ V-Cone® Flowmeter
The ExactSteam™ Solution

McCrometer’s ExactSteam solution is designed to overcome those hurdles.

The ExactSteam V-Cone Flowmeter works well with short straight-pipe runs, so it addresses the lack of space issues faced by colleges and universities. It also measures steam across the entire range, performing better at lower flows.

The High Cost Of Low Flow Cutoff

Steam system operators can pay a steep price for generating product that passes through a meter but fails to get measured. Also known as low flow cutoff, those losses are a function of the turndown ratio of flow meters. The ratio — defined as the maximum measurement capability of a device compared to its minimum — dictates how wide a flow spectrum can be measured. On campuses, this creates a major issue because demand for steam in the colder weather can be extremely high compared to off-peak times.

McCrometer’s ExactSteam
ExactSteam™ V-Cone® Flowmeter
ExactSteam is a DP-style flow meter that can be adjusted for colleges during winter months. It contains McCrometer’s established V-cone flow meter combined with a newer electronics package to aid in the downward adjustment of the turndown ratio. A growing number of college campuses, especially larger schools, are seeing the benefits of ExactSteam and adopting the technology.

Some examples include:

Case Study #1 - An East Coast University Steam Operation

This school designed its system to measure from 84,000 lbs/hr to 8,400 lbs/hr, which accounted for a 10:1 turndown ratio and velocities of 420’/second to 42’/second. After the meter was installed, system operators determined their actual flow range was 20,000 lbs/hr to 1,000 lbs/hr (a 20:1 turndown ratio) and velocities were 100’/second to 5’/second.

Because flow rates were overstated, the university dropped below the low flow cutoff and wasn’t measuring at all during the off-season.

The solution: Purchase another meter with a larger cone that would produce more differential pressure at the correct flows. The school has since installed an ExactSteam V-Cone Flowmeter.

Case Study #2 – A University Hospital Using Both Condensate And Steam Meters

During the winter, the steam meters were always measuring more steam than the condensate meters.  The difference was justified because the condensate meters were not capturing steam usage of the autoclaves.  However, during the summer, the condensate meters were measuring more than the steam meters, which was impossible.

The steam meter was designed for flows from 14,000 lbs/hr to 1,400 lbs/hr.  During the summer months the hospital flows frequently dropped below 1,400 lbs/hr, which was below the low flow cutoff.  It was also determined that their highest flow during the summer was 5,000 lbs/hr.  The hospital needed more turndown and a lower flow range.

The solution: The ExactSteam V-Cone Flowmeter was installed.  It was designed for flows from 6,000 lbs/hr to 300 lbs/hr and was able to fit in the basement between two elbows.

Well Positioned For Campus Use

Key aspects of McCrometer’s ExactSteam solution include: a complete flow meter for steam metering, factory-configured for energy metering or mass flow; the ability to measure saturated (dry), superheated, and unsaturated (wet) steam; the V-Cone acts as its own flow conditioner by disrupting all centralized flow disturbances; signal stability allows it to measure a wider range of flow than other meters, minimizing pressure loss; and minimum installation requirements, so retrofitting and new installations are easier.

Because of the inherent conflicts, traditional steam metering technologies are not a good fit for many colleges and universities. However, there are solutions available to campus steam system operators to capture readings from most — if not all — of their steam production, even in less than ideal conditions.

For more information on all aspects of flow measurement and campus metering, contact Flow-Tech, Inc. by calling 410-666-3200 in Maryland or 804-752-3450 in Virginia. Or, stop by their website at

Reprinted with permission from McCrometer.

Wednesday, April 24, 2019

Facility Energy Management and Optimization with Precision Ultrasonic Flow & Thermal Energy Meters

Campus energy management
The controlling, balancing, and monitoring of thermal energy flows is of utmost importance in times of rising energy prices, environmental regulations and financial benefits of energy efficient buildings.

FLEXIM, the leading manufacturer of non-intrusive, clamp-on ultrasonic flowmeters, offers thermal energy meters that make it easy to implement a system for more energy efficient buildings and facilities.

FLEXIM’s energy meters combine the attributes of non-intrusive ultrasonic flow measurement with superior temperature monitoring into an integrated energy computer. All flow transducers and temperature sensors are connected to one unit.

Precision Ultrasonic Flow & Thermal Energy Meter
Click for larger view.
  • Chiller Plants
  • Heating Plants
  • HVAC
  • Metering & Verification
  • Retrofits
  • Billing
  • Water Control / Leak Detection
  • Combined Heat and Power / Cogeneration Plants

Wednesday, April 17, 2019

White Paper: 5 Reasons to Consider EtherNet/IP™ for Your BioProcess

EtherNet/IP™ is one of the fastest growing digital communication protocols in industrial automation, continuing to gain wider acceptance as companies look to transition from fieldbus to ethernet networks.

Recognizing this trend, Brooks Instrument has worked closely with key customers and automation system suppliers to bring the EtherNet/IP™ protocol to its bioprocess-leading SLA5800 Series mass flow controllers. In 2018, Brooks announced availability of SLA5800 with EtherNet/IP™ with significant value-added alarm and diagnostic features.

This recent Brooks Instrument blog post lists 5 reasons why you need to consider EtherNet/IP™ for your bioprocess.

Wednesday, March 27, 2019

New Adaptive Sensing Technology for Thermal Mass Flow Meters

With the launch of its state-of- the-art ST80 Series thermal mass flow meter featuring breakthrough Adaptive Sensor Technology™ (AST™), the process industry’s air/gas flow measurement bar has been reset higher again for rangeability, accuracy, extended service life, reliability and application-matched solutions by Fluid Components International (FCI).

FCl’s innovative (AST™) thermal mass flow technology for the ST80 flow meters features an innovative hybrid sensor drive. This patent-pending measuring technique combines, for the first time, both of the industry’s highly proven constant power (CP) and constant temperature (CT) thermal dispersion sensing technologies in the same instrument. Complementing this new measurement drive technique are a choice of four different flow sensor element designs to further ensure best installed performance, including FCI’s new wet gas solution.

When operating in AST mode, the new ST80 flow meters measure in CT during start-up and through the lower flow ranges, and will then seamlessly shift into CP mode at mid-range and higher flow rates. The result is a best of both technologies performance level where the advanced ST80 meters deliver extremely fast response with extended measuring ranges, at low power consumption to maximize sensor reliability and reduce instrument energy expenses.

Flow-Tech, Inc.
410-666-3200 in Maryland
804-752-3450 in Virginia

Friday, March 8, 2019

Heavy Duty Portable Ultrasonic Water Flow Meter for Long-Term Field Measurement Situations


FLEXIM, the leader in clamp-on ultrasonic flow measurement, has a new portable flow meter designed for long-term field measurement situations.

Depending on programming, the FLUXUS F401 can operate autonomously for long periods, up to several months. This makes it perfect for leak detection investigations and hydraulic studies - anywhere regular, long-term measurements are needed.

FLUXUS F401Built with the water and wastewater industries in mind, the clamp-on ultrasonic flow meter system has is installed without process interruption and installation only takes a few minutes. From then on, the FLUXUS F401 delivers highly accurate and highly repeatable measurements that are not affected by drift. Its low flow capability (down to 0.01 m/s) makes the FLUXUS F401 perfectly suited for monitoring drinking water networks, where low flow velocities are common. The combination of strong signal output and internal noise suppression technology allows the FLUXUS F401 to be used confidently on very large pipes and challenging materials such as rusty steel, badly manufactured GRP, or even armored concrete pipes. These situations are not a metering challenge to the FLUXUS F401.

The product is designed from the ground up for regular heavy duty use in very rough conditions. All parts of the FLUXUS F401 are built to last. Metal sheathing of  protects the the transducer cable ends from tight bending as well as cuts, and ensures tangle-free operation. A six meter cable length of the IP68 transducer accommodates installation of the transducers in deep manholes, with the transmitter being safely located in the upper part of the manhole. The transmitter itself is housed in a robust case with IP67 protection.

The new FLEXIM FLUXUS F401 is ideal for the daily needs of water suppliers, hydrologists and engineering offices. For more information, contact Flow-Tech, Inc. In Maryland call 410-666-3200. In Virginia call 804-752-3450, or visit Flow-Tech on the web at

Tuesday, February 26, 2019

The Brooks GT1600 Industrial Glass Tube Variable Area Flowmeter

The Brooks Instrument GT1600 Series glass tube VA flow meters are a NEW family of meters with a rugged design for long-lasting performance with low and high-flow gas and liquid applications where viewing the process is important. These versatile and economical meters are for general use in applications with moderate metering accuracy requirements — typical accuracy ranges are 1% to 10% full scale, depending on the model selected. They are ideal for purge type service, seal oil systems, bearing lubrication and cooling water indication.

The GT1600 Series flow meters are configurable to retro-fit existing Brooks Instrument GT1000, GT1300 and Full-View® 1100 Series meters (models 1110, 1114, 1140, 1144).

Contact Flow-Tech, Inc. about Brooks Instrument products in Maryland and Virginia.
MD: 410-666-3200
VA:  804-752-3450

Monday, February 18, 2019

Drager REGARD 7000 Fixed Gas Detection Systems Product Series

Dräger REGARD<sup>®</sup> 7000
Dräger REGARD® 7000
The Dräger REGARD® 7000 is a modular and therefore highly expandable analysis system for monitoring various gases and vapors. Suitable for gas warning systems with various levels of complexity and numbers of transmitters, the Dräger REGARD® 7000 also features exceptional reliability and efficiency. An additional benefit is the backward compatibility with the REGARD®.

Download complete Dräger REGARD® 7000 brochure and specification from this link on the Flow-Tech website.

Flow-Tech, Inc.
MD: 410-666-3200
VA:  804-752-3450

Tuesday, January 29, 2019

Industrial Automation and the Implementation of Wireless Technology

The use of wireless technology in industrial automation systems offers a number of potential benefits, from the obvious cost reduction brought about by the elimination of wiring to the availability of better plant information, improved productivity and better asset management.

However, its practical implementation faces a number of challenges: not least the present lack of a universally agreed standard. This article looks at some of these challenges and presents the approach being taken by Yokogawa.

Download Your Copy Of "Wireless Technology In Industrial Automation" here.

Saturday, January 19, 2019

Understanding the Operation of Thermal Mass Flow Controllers

In this video, Brooks Instrument presents the operation of thermal mass flow controllers.

Mass Flow Controllers are also referred to as MFCs. The basic construction of mass flow controllers consists of four main components. A body, a thermal sensor, a printed circuit board and a magnetic control valve. As gas enters the flow body, a laminar flow element or restrictor diverts precise portion of the gas to pass through the thermal sensor. The thermal sensor is the heart of the mass flow controller, and consists of a bypass tube fitted with a heater element and two temperature sensors. As gas enters the sensor bypass tube, the upstream and downstream temperature sensors measure the temperature differential between gas entering the bypass tube and exiting the bypass tube. 

When choosing an MFC supplier, consider whether the manufacturer provides a zero stability specifications, also known a sensor stability. This indicates the devices ability to maintain accuracy over time. Good sensor stability ensures the MFC delivers highly accurate and consistent results with less frequent recalibration or replacements needed. A stable, accurate sensor guarantees stable, accurate process control. As the thermal sensor measures the change in flow temperature,  it sends a signal to the circuit board, which interprets the data into flow output and compares it to the set point received from the user set point signal. If the set point, or required value, is higher than the measured value or flow output, the controller will open the control valve, letting more flow through. If the set point is lower than the flow output, the control valve will close, decreasing flow. This happens when a coil inside the magnetic control valve sends an electrical current around a valve stem, which moves the valve plunger by thousands of an inch. The circuit board is the brain of the device, so pay close attention to the electronics and firmware architecture when evaluating an MFC. The device should have the ability to support advanced alarms and diagnostics to monitor and correct issues before the overall process is negatively affected. Check to see what built in alarms and diagnostics are available. 

Brooks Instrument devices support not only flow output, but additional alerts like flow totalization, valve drive, plugged flow and calibration. All of Brooks devices are tested as complete systems to ensure robust and accurate operation and are calibrated to international standards. Contact Flow-Tech to learn which solution is right for your process.

Flow-Tech, Inc.
410-666-3200 in Maryland
804-752-3450 in Virginia