Saturday, November 11, 2017

Clamp-on, Transit-time Difference Ultrasonic Flowmeters Ideal for HVAC Retrofit and New Construction

Transit-time Difference Ultrasonic Flowmeters
Transit-time Difference Ultrasonic Flowmeters (Flexim)
There are many reasons for large commercial buildings, medical centers, museums, airports, sports complexes, federal institutions and military complexes to invest in building energy optimization efforts. Better and more efficient operation of HVAC equipment can reduce the buildings energy and operational costs significantly.

Controlling flow, temperature and pumps can provide energy cost savings of over 20%. Many campus energy managers believe that the biggest user of energy in any complex is the HVAC system, and the key to saving energy in HVAC systems is an accurate and reliable flow metering capability.

Better efficiency of the heating and cooling infrastructure of a building also leads to more environmentally friendly buildings, something that has become a social prerogative of building owners and operators.  Older buildings were not built with BTU meters as metering requirements were added to buildings through increased regulations.

Submetering the buildings heating and cooling systems have become increasingly more important, as building owners are both mandated to meter these utilities and have a financial interest in the accuracy of these BTU measurements. The problem historically is that nearly all flow meters are designed for gradual failure due to direct contact with the fluids they are monitoring and the particulate accumulation on the sensors.

Clamp-on, transit-time difference ultrasonic flowmeters are the ideal retro-fit flowmeter, and also should receive strong consideration for new building construction. Transit-time difference ultrasonic clamp on flowmeters exploit the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium - kind of like a swimmer swimming against the current. The signal moves slower against the flow than with it.

How Transit-time Difference Ultrasonic Flowmeters Work

The flowmeter sends ultrasonic pulses through the process medium - one in the same direction as the
flow and one in the opposite direction. The flowmeter's transducers alternate as emitters and receivers. The transit time of the signal going with the flow is shorter than the one going against. The flowmeter measures transit-time difference and determines the average flow velocity of the process medium. Since ultrasonic signals propagate in solids, the flowmeter can be conveniently mounted directly on the pipe and measure flow non-invasively.

Contact Flow-Tech with your questions about any flow measurement application. Reach them at 410-666-3200, or visit http://www.flowtechonline.com.

Tuesday, October 31, 2017

Understanding HART Protocol

A current loop using sensing and
control transmission with HART protocol
overlaid on the 4–20 mA loop.
The Highway Addressable Remote Transducer Protocol, also known as HART, is a communications protocol which ranks high in popularity among industry standards for process measurement and control connectivity. HART combines analog and digital technology to function as an automation protocol.

A primary reason for the primacy of HART in the process control industry is the fact that it functions in tandem with the long standing and ubiquitous process industry standard 4-20 mA current loops.

The 4-20 mA loops are simple in both construction and functionality, and the HART protocol couples with their technology to maintain communication between controllers and industry devices. PID controllers, SCADA systems, and programmable logic controllers all utilize HART in conjunction with 4-20 mA loops.

HART instruments have the capacity to perform in two main modes of operation: point to point, also known as analog/digital mode, and multi-drop mode. The point to point mode joins digital signals with the aforementioned 4-20 mA current loop in order to serve as signal protocols between the controller and a specific measuring instrument. The polling address of the instrument in question is designated with the number ì0î. A signal specified by the user is designated as the 4-20 mA signal, and then other signals are overlaid on the 4-20 mA signal. A common example is an indication of pressure being sent as a 4-20 mA signal to represent a range of pressures; temperature, another common process control variable, can also be sent digitally using the same wires. In point to point, HART’s digital instrumentation functions as a sort of digital current loop interface, allowing for use over moderate distances.

HART in multi-drop mode differs from point to point. In multi-drop mode, the analog loop current is given a fixed designation of 4 mA and multiple instruments can participate in a single signal loop. Each one of the instruments participating in the signal loop need to have their own unique address.

Image courtesy of  Dougsim (Own work) [CC BY-SA 4.0], via Wikimedia Commons

Tuesday, October 24, 2017

Vibration Analysis in Manufacturing and Process Control

Vibration graph
Image courtesy of Wikipedia
As all of us who ride or drive an automobile with some regularity know, certain mechanical faults or problems produce symptoms that can be detected by our sense of feel. Vibrations felt in the steering wheel can be an indicator of an out-of-balance wheel or looseness in the steering linkage. Transmission gear problems can be felt on the shift linkage. Looseness in exhaust system components can sometimes be felt as vibrations in the floorboard. The common thread with all these problems is that degeneration of some mechanical device beyond permissible operational design limitations has manifested itself by the generation of abnormal levels of vibration. What is vibration and what do we mean by levels of vibration? The dictionary defines vibration as “a periodic motion of the particles of an elastic body or medium in alternately opposite directions from the position of equilibrium when that equilibrium has been disturbed or the state of being vibrated or in vibratory motion as in (1) oscillation or (2) a quivering or trembling motion.”

The key elements to take away from this definition are vibration is motion, and this motion is cyclic around a position of equilibrium. How many times have you touched a machine to see if it was running? You are able to tell by touch if the motor is running because of vibration generated by motion of rotational machine components and the transmittal of these forces to the machine housing. Many parts of the machine are rotating and each one of these parts is generating its own distinctive pattern and level of vibration. The level and frequency of these vibrations are different and the human touch is not sensitive enough to discern these differences. This is where vibration detection instrumentation and signature analysis software can provide us the necessary sensitivity. Sensors are used to quantify the magnitude of vibration or how rough or smooth the machine is running. This is expressed as vibration amplitude. This magnitude of vibration is expressed as:

Displacement – The total distance traveled by the vibrating part from one extreme limit of travel to the other extreme limit of travel. This distance is also called the “peak-to-peak displacement.”

Velocity – A measurement of the speed at which a machine or machine component is moving as it undergoes oscillating motion.

Acceleration – The rate of change of velocity. Recognizing that vibrational forces are cyclic, both the magnitude of displacement and velocity change from a neutral or minimum value to some maximum. Acceleration is a value representing the maximum rate that velocity (speed of the displacement) is increasing.

GE Bently Nevada
GE Bently Nevada is a leading provider of vibration
analysis instruments and software.
Various transducers are available that will sense and provide an electrical output reflective of the vibrational displacement, velocity, or acceleration. The specific unit of measure to best evaluate the machine condition will be dependent on the machine speed and design. Several guidelines have been published to provide assistance in determination of the relative running condition of a machine. It should be said that guidelines are not absolute vibration limits above which the machine will fail and below which the machine will run indefinitely. It is impossible to establish absolute vibration limits. However, in setting up a predictive maintenance program, it is necessary to establish some severity criteria or limits above which action will be taken. Keep in mind that guidelines are not intended to be used for establishing vibration acceptance criteria for rebuilt or newly installed machines. They are to be used to evaluate the general or overall condition of machines that are already installed and operating in service. For those, setting up a predictive maintenance program, lacking experience or historical data, similar charts can serve as an excellent guide to get started.

As indicated earlier, many vibration signals are generated at one time. Once a magnitude of vibration exceeds some predetermined value, vibration signature analysis can be used in defining the machine location that is the source of the vibration and in need of repair or replacement. By using analysis equipment and software, the individual vibration signals are separated and displayed in a manner that defines the magnitude of vibration and frequency. With the understanding of machine design and operation, an individual schooled in vibration signature analysis can interpret this information to define the machine problem to a component level.

Vibration monitoring and analysis can be used to discover and diagnose a wide variety of problems related to rotating equipment. The following list provides some generally accepted abnormal equipment conditions/faults where this predictive maintenance technology can be of use in defining existing problems:
  • Unbalance
  • Eccentric rotors
  • Misalignment
  • Resonance problems
  • Mechanical looseness/weakness
  • Rotor rub
  • Sleeve-bearing problems
  • Rolling element bearing problems
  • Flow-induced vibration problems
  • Gear problems
  • Electrical problems
  • Belt drive problems
Analyzing equipment to determine the presence of these problems is not a simple and easily performed procedure. Properly performed and evaluated vibration signature analysis requires highly trained and skilled individuals, knowledgeable in both the technology and the equipment being tested. Determination of some of the problems listed is less straightforward than other problems and may require many hours of experience by the technician to properly diagnosis the condition.

To learn more about vibration analysis and critical asset monitoring, contact Flow-Tech at 410-666-3200 or visit http://www.flowtechonline.com.

Article abstracted from US DOE Operations & Maintenance Best Practices Release 3.0

Thursday, October 19, 2017

Centralized Gas Monitoring for Industry

Drager REGARD 7000
The Drager REGARD 7000 is a modular and 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 Drager REGARD 7000 also features exceptional reliability and efficiency. An additional benefit is the backward compatibility with the REGARD.

For more information in Maryland or Virginia, contact Flow-Tech at 410666-3200 or visit http://www.flowtechonline.com.

Check out the video below to learn more about the Drager REGARD 7000. Thanks for watching.

Monday, October 9, 2017

5 Myths of Dust Explosion Propagation

Fike explosion testing
Dust explosion propagation testing at Fike labs.
Abstracted from
"Dust Explosion Propagation: Myths and Realities"
by Fike Corporation


The unfortunate propensity of dust explosions to destroy entire facilities and claim lives has been reported in numerous past incidents.

Powder handling processes are often comprised of interconnected enclosures and equipment. Flame and pressure resulting from a dust explosion can therefore propagate through piping, across galleries, and reach other pieces of equipment or enclosures, leading to extensive damage.

While the ability of dust explosions to propagate has been widely recognized, some misconceptions lead to the false sense of security that explosion isolation is not required.

This post will enumerate, illustrate and unravel 5 common myths about explosion propagation. Download the full Fike White Paper here, or read it in full at the bottom of this post.

Myth #1: A large amount of dust is needed for an explosion to propagate.

Dust explosions do not need large amounts of fuel to propagate.

A 1 mm layer can create a dust explosion hazard in a typical room. The explosion only needed a 1/100 inch layer of dust on the ground to fully propagate.

Myth #2: A dust explosion starting in a vented vessel cannot propagate through connected pipes.

It is a common belief that protecting an enclosure, by means of venting or suppression, will affect explosion propagation in such a manner that no explosion isolation is needed at all. 

Although venting protects a vessel from the high pressures generated by an explosion, it does not necessarily prevent the explosion from being propagated through piping into other vessels.

Myth #3: A dust explosion cannot propagate against process flow. 

An argument also often heard is that a dust explosion cannot propagate against pneumatic process flow. 

An explosion is capable of traveling both with and against process flow, even over long distances.

Myth #4: A dust explosion weakens as it propagates.

Literature includes numerous discussions about explosion behavior in interconnected vessels. 

Experimental evidence has shown that explosions not only propagate, but become increasingly more damaging.

Myth #5: Small diameter pipes do not support dust explosion propagation.

Dust explosion propagation in small pipes has always been a controversial topic. The primary argument being that flame propagation is challenged due to heat loss to the pipe walls.

While conditions for dust explosions to propagate in relatively small diameter pipes are not yet fully established, their ability to propagate has been clearly demonstrated by several researchers.

Contact Flow-Tech with any questions regarding explosion protection testing, isolation valves, vents and systems at http://www.flowtechonline.com or call 410-666-3200.

Saturday, September 30, 2017

Campus Metering: Why Meter?

Instrumentation Energy Management
Schools, universities, medical centers and federal building
use instrumentation for energy management.

Energy and water managers have long known the value of metered data. With recent advances in energy and water metering and information systems resulting in increased functionality at lower costs, obtaining these data in a cost-effective manner is now a standard practice. Whether energy and water resource managers are trying to comply with legislated and mandated metering requirements, or looking to apply accepted building management best practices, such as utility bill verification or benchmarking, today’s metering technologies can provide the information needed to meet energy and water goals, save money, and improve building operations.

Metering of energy and water utilities has seen an increase in interest, application, and technology
Clamp-on flow meter
Clamp-on flow meter (Flexim)
advancement in both the private and the public sectors. One significant driver of this heightened interest is the ongoing modernization of the nation’s electric infrastructure with the move toward the smart grid and smart meters. Another significant driver, specific to the Federal sector, includes the legislative mandates for metering of Federal buildings.

The Business Case for Metering

The application of meters to individual buildings and energy-intensive equipment provides facility managers and operators with real-time information on how much energy has been or is being used. This type of information can be used to assist in optimizing building and equipment operations, in utility procurements, and in building energy budget planning and tracking.

It is important to keep in mind that meters are not an energy efficiency/energy conservation technology per se; instead, meters and their supporting systems are resources that provide building owners and operators with data that can be used to: 
Flow computer
Flow computer (KEP)
  • Reduce energy and water use
  • Reduce energy and water costs
  • Improve overall building operations 
  • Improve equipment operations
How the metered data are used is critical to a successful metering program.

Depending on the type of data collected, these data can enable the following practices and functions:
  • Verification of utility bills
  • Comparison of utility rates
  • Proper allocation of costs or billing of reimbursable tenants 
  • Demand response or load shedding when purchasing electricity under time-based rates 
  • Measurement and verification of energy project performance 
  • Benchmarking building energy use 
  • Identifying operational efficiency improvement opportunities and retrofit project opportunities 
  • Usage reporting and tracking in support of establishing and monitoring utility budgets and costs, and in developing annual energy reports. 
Most of the metered data uses listed above will result in a reduction in energy and water costs. The degree of cost reduction realized will depend on the unit cost of the energy and water being saved and on the effectiveness with which the site analyzes the data and acts upon its findings and recommendations. Examples of additional metering benefits can include:
Inline flowmeter
Thermal dispersion flow meter (FCI)
  • Supporting efforts to attain ENERGY STAR and/or green building certifications 
  • Promoting tenant satisfaction by providing information that tenants find useful in managing their operations 
  • Prolonging equipment life (and reducing capital investment requirements) and improving its reliability by verifying the efficient operation of equipment 
  • Assessing the impact of utility price fluctuations prior to or as they happen, allowing sites/agencies to address budget shortfalls on a proactive basis. 
Metering options will change in response to new material, electronic, and sensor development, as well as new and additional requirements for real-time data information. Future expansion of a metering system should be considered, as well as introduction of new metering and sensor technologies, based on the best available information, but be careful not to over design a system, thus unnecessarily increasing its cost.

Contact Flow-Tech with questions about improving your facilities energy management systems.  

Tuesday, September 12, 2017

ADMAG TI Series AXW Magnetic Flowmeter Maintenance Manual

ADMAG TI Series AXW Magnetic Flowmeter
ADMAG AXW Magnetic Flowmeter
(Yokogawa)
The ADMAG AXW™ series of magnetic flow meters has been developed based on Yokogawa's decades-long experience in Magnetic Flowmeters. The AXW series continues the tradition of high quality and reliability that has become synonymous with the Yokogawa name.

The AXW series is ideal for industrial process lines, and water supply / sewage applications. With outstanding reliability and ease of operation, developed on decades of field-proven experience, the AXW will increase user benefits while reducing total cost of ownership.

Sizes are available from 500 to 1800 mm (20 to 72 inch.) with a wide liner selection such as PTFE, Natural hard rubber, Natural soft rubber, and Polyurethane rubber lining. Offering industry standard process connections such as ASME, AWWA, EN, JIS, and AS flange standards. A submersible version is also available.

This manual provides the basic guidelines for maintenance procedures of ADMAG TI (Total Insight) Series AXW magnetic  flowmeters.

In Virginia, contact Flow-Tech for any Yokogawa instrument requirement you may have. Call 804-752-3450 or visit http://www.flowtechonline.com.

Monday, September 11, 2017

Industrial Level Measurement

Point level
Point level switch (FCI)
In many industrial processes, the measurement of level is critical. Depending on the nature of the material being measured, this can be a simple or complex task. Several different technologies for sensing level are briefly explained here.

Direct Method

The direct method of level measurement calculates levels instantly using physical properties, like buoyancy and fluid motion. Beginning from the simplest, the following are the three main types:
  • Sight glass type
  • Float type
  • Magnetic level gauge
Sight glass measures liquid in tanks. A scaled glass tube with metallic covering it is attached to the top and bottom edges of the tank and, as the liquid moves up and down, the level in the tube fluctuates in the same way.

Float type measurement makes use of buoyancy: a float device follows the liquid level while sitting atop it. As the liquid moves so does the float device; a cable, attached to the top of the device, is rigged to a calibrated scale with a pointer in the middle. The up and down movements pull the string which pulls the pointer, thus showing where the liquid level is.

 A magnetic level gauge looks like a thick thermometer and is attached to the end of a vertical chamber. This vertical chamber contains a magnetic float, a permanent magnet, which floats on the top of the liquid level in the tank.

There is one more thing also attached to the outside of the tank: an indicating scale with small metallic strips. These strips are white and red sided flippers, rotating 180° whenever the float magnet attracts them while passing over. Whenever the float magnet is above, the strips will flip red side up, indicating the tank’s level.

Indirect Method

In the indirect method of level measurement, the level of a liquid is calculated by a variable that changes according to the level. There are four main types:

  • Pressure gauge type
  • Differential pressure type
  • Ultrasonic type
  • Radar type
The pressure gauge is a simple method; a pressure gauge is attached near the bottom of tank and pressure, exerted by the tank, is calculated. The gauge changes in time with the tank’s liquid pressure, and the measurement is made according to the height of the liquid.

Radiometric Level
Radiometric Level (RONAN)
The differential pressure method (DP method) is another widely used method in industry. This method requires a DP transmitter and a port; these two parts are connected to the external tank at opposite ends. The differential pressure in the tank is measured between the DP transmitter at the bottom and the port at the top; the output of the differential pressure calculated by the DP transmitter is proportional to the liquid level. The more liquid in the tank, the more pressure is at the transmitter; the less liquid in the tank, the more pressure at the port.

The ultrasonic method is a no-contact type. A transmitter is mounted atop the tank and ultrasonic sound waves are sent from the transmitter toward the surface of the measured fluid. An echo of the wave is calculated and the time it took for the wave to reach its end goal from the transmitter becomes its distance. The time of the length of the distance is then calibrated in terms of the level of process material.

The radar method is a no-contact type and it uses electromagnetic waves. Electromagnetic waves are sent through a transmitter to the surface of the measured material. There is a receiver toward the bottom of the tank which takes a portion of the energy sent from the wave and then reflects it back toward the surface of the medium. The reflected energy then becomes calibrated into level measurement.

Industrial level control requires deep knowledge and understanding of many process variables, such as media compatibility, interfaces, head pressures, material densities, and mechanical considerations. It's always recommended that an experienced consultant be involved with the selection and implementation of any industrial level device.

Wednesday, September 6, 2017

Fluid Components Series FS10 Quick Setup Mode Demonstration

FS10 Series Flow Switch and Monitor
FS10 Series Flow Switch and Monitor
The FS10 Series Flow Switch and Monitor is manufactured by Fluid Components, Inc.

The FS10A is a universal flow switch and monitor specifically designed for gas and liquid process analyzer sampling systems. The FS10A is a fast responding, highly repeatable sensor which installs easily into a standard tube tee fitting or new SP76 (NeSSI) modular manifold.

The FS10i is a universal flow switch and flow monitor designed for simple insertion into ½” (13mm) or larger diameter pipes and square ducts. The unit is suitable for either liquid or air/gas applications. It is fast responding and highly repeatable to both increasing and decreasing flow rate changes.

The video below explains the procedure for accessing and setting the quick setup modes.

For more information on any Fluid Components, Inc. (FCI) flow meter in Maryland and Virginia, call 410-666-3200 or visit http://www.flowtechonline.com.

Thursday, August 31, 2017

Process Instrument Calibration

Meriam MFC5150 HART Communicator
Meriam MFC5150
HART Communicator
Calibration is an essential part of keeping process measurement instrumentation delivering reliable and actionable information. All instruments utilized in process control are dependent on variables which translate from input to output. Calibration ensures the instrument is properly detecting and processing the input so that the output accurately represents a process condition. Typically, calibration involves the technician simulating an environmental condition and applying it to the measurement instrument. An input with a known quantity is introduced to the instrument, at which point the technician observes how the instrument responds, comparing instrument output to the known input signal.

Even if instruments are designed to withstand harsh physical conditions and last for long periods of time, routine calibration as defined by manufacturer, industry, and operator standards is necessary to periodically validate measurement performance. Information provided by measurement instruments is used for process control and decision making, so a difference between an instrument's output signal and the actual process condition can impact process output or facility overall performance and safety.

In all cases, the operation of a measurement instrument should be referenced, or traceable, to a
universally recognized and verified measurement standard. Maintaining the reference path between a field instrument and a recognized physical standard requires careful attention to detail and uncompromising adherence to procedure.

Calibration gauges
Calibration gauges (Permacal)
Instrument ranging is where a certain range of simulated input conditions are applied to an instrument and verifying that the relationship between input and output stays within a specified tolerance across the entire range of input values. Calibration and ranging differ in that calibration focuses more on whether or not the instrument is sensing the input variable accurately, whereas ranging focuses more on the instrument's input and output. The difference is important to note because re-ranging and re-calibration are distinct procedures.

In order to calibrate an instrument correctly, a reference point is necessary. In some cases, the reference point can be produced by a portable instrument, allowing in-place calibration of a transmitter or sensor. In other cases, precisely manufactured or engineered standards exist that can be used for bench calibration. Documentation of each operation, verifying that proper procedure was followed and calibration values recorded, should be maintained on file for inspection.

As measurement instruments age, they are more susceptible to declination in stability. Any time maintenance is performed, calibration should be a required step since the calibration parameters are sourced from pre-set calibration data which allows for all the instruments in a system to function as a process control unit.

Typical calibration timetables vary depending on specifics related to equipment and use. Generally, calibration is performed at predetermined time intervals, with notable changes in instrument performance also being a reliable indicator for when an instrument may need a tune-up. A typical type of recalibration regarding the use of analog and smart instruments is the zero and span adjustment, where the zero and span values define the instrument's specific range. Accuracy at specific input value points may also be included, if deemed significant.

The management of calibration and maintenance operations for process measurement instrumentation is a significant factor in facility and process operation. It can be performed with properly trained and equipped in-house personnel, or with the engagement of subcontractors. Calibration operations can be a significant cost center, with benefits accruing from increases in efficiency gained through the use of better calibration instrumentation that reduces task time.

Contact Flow-Tech at 410-666-3200 in Maryland and 804-752-3450 in Virginia for any calibration question or requirement.

Monday, August 28, 2017

Installation and Operation of the Brooks Instrument GF40

Brooks Instrument GF40
Brooks Instrument GF40
The Brooks® GF40 (elastomer seal) thermal mass flow controller (MFC) and thermal mass flow meter (MFM) achieves unprecedented performance, reliability, and flexibility in many gas flow measurement and control applications.

At the heart of the GF40 is Brooks’ patented 4th generation MultiFloTM capable device. MultiFlo overcomes a long-standing limitation of many thermal MFCs – when changing gas types, a simple correction factor, such as the ratio of heat capacities between the calibration gas and new gas, cannot account for accuracy-robbing viscosity and density differences. The Brooks MultiFlo database is built on thousands of native gas runs to establish correction functions that account for both thermal and physical differences among gases making the GF40 Series among the most accurate and flexible MFCs/MFMs available today. The Brooks GF40 Series is the perfect choice for customers who use thermal mass flow controllers or thermal mass flow meters on a variety of gases, who need to change gas type frequently, or who need to re-range while preserving gas measurement and control accuracy.

We have provided a Brooks GF40 installation and operation manual below for your convenience. To download your own Brooks GF40 IOM (PDF), click this link.

Friday, August 18, 2017

Explosion and Fire at Chemical Plant Case Study

Fire and explosion testing to mitigate risk.
Fire and explosion testing to mitigate risk. (Fike)
Industrial accidents, whether minor or catastrophic, can serve as sources of learning when analyzed and studied. Operators, owners, and technicians involved with industrial chemical operations have a degree of moral, ethical, and legal responsibility to conduct work in a reasonably and predictably safe manner without endangering personnel, property, or the environment.

Part of a diligent safety culture should include reviewing industrial accidents at other facilities. There is much to learn from these unfortunate events, even when they happen in an industry that may seem somewhat removed from our own.

The U.S. Chemical Safety Board, or CSB, is an independent federal agency that investigates industrial chemical accidents. Below, find one of their video reenactments and analysis of an explosion that occurred at a Louisiana chemical processing plant in 2013. A portion of the reenactment shows how a few seemingly innocuous oversights can combine with other unrecognized conditions that result in a major conflagration.

For more information on industrial plant safety products that mitigate fire and explosion risk,  contact Flow-Tech at 410-666-3200 in Maryland, or 804-752-3450 in Virginia

Thursday, August 3, 2017

Pressure Sensor Accessories - Filled Impulse Line

welded isolating diaphragm for pressure sensing line
An isolating diaphragm, such as this variety
pictured, can be used as a barrier between
process fluid and sensing line fill.
Image courtesy REO Temp 
Pressure sensors intended for use in industrial process measurement and control applications are designed to be robust, dependable, and precise. Sometimes, though, it is necessary or beneficial to incorporate accessories in an installation which augment the performance of pressure sensors in difficult or hazardous environments. There are some scenarios where the sensor must be isolated from the process fluid, such as when the substance is highly corrosive or otherwise damaging to the pressure sensor.

A way to aid pressure sensing instruments in situations where direct contact must be avoided is by using a filled impulse line. An impulse line extends from a process pipe of vessel to a pressure measurement instrument or sensor. The line can have a diaphragm barrier that isolates the process fluid from the line, or the line can be open to the process. There are best practices that should be followed in the design and installation of an impulse line to assure that the line provides a useful transmission of the process pressure to the sensor and whatever degree of isolation or protection is needed remains in effect.

The filled impulse line functions via the addition of a non-harmful, neutral fluid to the impulse line. The neutral fluid acts as a barrier and a bridge, allowing the pressure sensing instrument to measure the pressure of the potentially harmful process fluid without direct contact. An example of this technique being employed is adding glycerin as a neutral fluid to an impulse line below a water pipe.

Glycerin's freeze point is lower than waters, meaning glycerin can withstand lower temperatures before freezing. The impulse line connected to the water pipe may freeze in process environments where the weather is exceptionally cold, since the impulse line will not be flowing in the same way as the water pipe. Since glycerin has a greater density and a lower freezing point, the glycerin will remain static inside the impulse line and protect the line from hazardous conditions.
pressure transmitter
Filled impulse lines protect pressure
transmitters from the adverse impact
of aggressive process fluids.


The use of an isolating diaphragm negates the need for certain considerations of fill fluid density, piping layout, and the need to create an arrangement that holds the fill fluid in place within the impulse line. System pressure will be transferred across the diaphragm from the process fluid to the fill fluid, then to the pressure sensor. It is important to utilize fluids and piping arrangements that do not affect the accurate transference of the process pressure. Any impact related to the impulse line assembly must be determined, and appropriate calibration offset applied to the pressure sensor reading.

An essential design element of a filled impulse line without an isolating diaphragm is that the fill fluid must be compatible with the process fluid, meaning there can be no chemical reactivity between the two. Additionally, the two fluids should be incapable of mixing no matter how much of each fluid is involved in the combination. Even with isolating diaphragms employed, fluid harmony should still be considered because a diaphragm could potentially loose its seal. If such a break were to occur, the fluids used in filled impulse lines may contact the process fluid, with an impact that should be clearly understood through a careful evaluation.

Tuesday, July 25, 2017

Fieldbus Equipped Instrumentation - Part Two

Since automatic control decisions in FOUNDATION fieldbus are implemented and executed at the field instrument level, the reliance on digital signals (as opposed to analog) allows for a streamlined configuration of direct control system ports. If the central control device were to become overloaded for any reason, tasks related to control decisions could still be implemented by operators in the field. This decentralization of the system places less burden and emphasis on the overall central control unit, to the point where, theoretically, the central control unit could stop functioning and the instrumentation would continue performing process tasks thanks to the increased autonomy. Allowing for the instrumentation to function at such an increased level of operation provides a proverbial safety net for any system related issues, with the capacity for independent functionality serving as both a precaution and an example for how process technology continues to evolve from analog solutions to fully end to end digital instrumentation.

Even in terms of the FOUNDATION instrumentation itself, there were two levels of networks being developed at this increased level of operation, initially: the first, H1, was considered low speed, while H2 was considered high speed. As the design process unfolded, existing Ethernet technology was discovered to fulfill the needs of the high speed framework, meaning the H2 development was stopped since the existing technology would allow for the H1 network to perform to the desired standards. The physical layer of the H1 constitutes, typically, a two-wire twisted pair ungrounded network cable, a 100 ohm (typical) characteristic impedance, DC power being conveyed over the same two wires as digital data, at least a 31.25 kbps data rate, differential voltage signaling with a defined threshold for both maximum and minimum peak receive rates, and Manchester encoding. Optical fiber can be used on some installations in lieu of the twisted pair cable.

Most of these specifications were exactly designed to withstand extremely challenging process control environments while still not abandoning the philosophy of being easy to build and implement, especially in terms of new system establishment. The most crucial aspects of many process control systems are streamlined together, allowing for consistent communication and synchronization. All aspects are viewable from both the legacy central controller and also via each individual device. Despite the data rate of 31.25 kbps being relatively slow, what is sacrificed in terms of speed is more than made up for in terms of the system being compatible with imperfect cables and other hiccups which may destabilize a network with faster speeds. The evolved technology, ease of installation, and durability have made the H1 network a widely used implementation of the FOUNDATION fieldbus technology. Fieldbus is currently considered one of a few widely adopted industrial process control communications protocols.

For more information contact Flow-Tech in Maryland at 410-666-3200; in Virginia at 804-752-3450, or visit http://www.flowtechonline.com.

Saturday, July 22, 2017

Fieldbus Equipped Instrumentation - Part One

Autonomous control and digital instrumentation are two capabilities enabling highly precise or complex execution of process control functions. FOUNDATION fieldbus instrumentation elevates the level of control afforded to digital field instrumentation where, instead of only communicating with each other, instruments involved in particular process control systems can independently facilitate algorithms typically reserved for instruments solely dedicated to controlling other instruments. Fieldbus capable instrumentation has become the standard instrumentation for many process industry installations due to the fact the FOUNDATION design principle streamlines process systems. A large contributor to FOUNDATION's success has been faster installation as opposed to operational controllers which do not feature the fieldbus configuration. Newer process companies, or process control professionals seeking to establish a new system, have gravitated towards fieldbus due to the combined advantages of system conciseness and ease of implementation.

In a typical digital control system, dedicated controllers communicate with field instrumentation (the HART protocol is a prime example of digital communication at work in the industry). The host system controls configuration of instruments and serves as a central hub where all relevant control decisions are made from a single dedicated controller. Typically, these networks connect controllers and field devices through coupling devices and other buses which streamline many different instruments into a complete system.

FOUNDATION fieldbus approaches the same network scheme with an important difference. Whereas in a legacy or more conventional system, either algorithmic or manual decisions would need to be implemented via the dedicated system level controllers, instruments utilizing FOUNDATION fieldbus architecture can execute control algorithms at the local device level. The dedicated controller hub is still present, so that operators can view and monitor the entire network concurrently and make status changes. Algorithmic execution of control functions becomes entirely device reliant thanks to the FOUNDATION protocol. Additionally, even though FOUNDATION implements an advanced configuration, some operators use the capabilities introduced in the fieldbus upgrade to implement specific algorithms via each device while concurrently maintaining algorithms in the central controller. This dual algorithmic configuration allows for several advantages, including the ability for increased system precision.

Since individual devices in the control process are calibrated and able to execute their own control functions, issues in the process with particular devices can be isolated and dealt with in a more specified manner by technicians using the instruments in the field. The central operator retains the capacity to use the control hub to alter and direct the control system.

For more information contact Flow-Tech in Maryland at 410-666-3200; in Virginia at 804-752-3450, or visit http://www.flowtechonline.com.

Watch for Part Two of this series to be posted soon.

Saturday, July 15, 2017

Solving Critical Process Applications for the Water and Wastewater Industry

Thermal Dispersion and Coriolis technology
From the early 1960s, Fluid Components International recognized the need for flow and level instrumentation which met specific customer requirements and demands for the Water and Wastewater Industry. By utilizing Thermal Dispersion and Coriolis technology exclusively in all FCI flow, level, interface, temperature switches and mass flow meters, our products solve typical Water and Wastewater Industry application challenges with standard product features such as:
  • No moving parts
  • All welded materials of construction 
  • Direct mass flow measurement
  • No pressure drop
  • Explosion-proof design
  • Wide flow range
  • Low flow capability
The document below outlines where and how Thermal Dispersion and Coriolis technology are used throughout water treatment facilities around the USA.

For more information on any water treatment process application, contact Flow-Tech at 410-666-3200 in Maryland, or 804-752-3450 in Virginia, or visit http://www.flowtechonline.com.

Sunday, July 9, 2017

The Yokogawa TDLS8000 Tunable Diode Laser Spectrometer

TDLS8000
The Yokogawa TDLS8000
The Yokogawa TDLS8000 can quickly make in-situ measurements of gas concentrations in combustion and heating processes that are employed in the oil, petrochemical, electric power, iron and steel, and other industries.

Companies are always looking for ways to optimize processes by saving energy, reducing CO2 emissions, and improving safety and one way to do this is by optimizing the air-fuel ratio in the combustion process. To accomplish this, sensors are needed that can continuously monitor the concentration of O2 and CO+CH4 in the radiant section of fired heaters.

Product Features

  1. Highly reliable measurement - The TDLS8000's laser module includes a newly developed reference cell board that improves the reliability of absorption peak detection, which is an important step in the spectral area method. In addition, the receiving unit employs a new auto gain function that can automatically optimize detection sensitivity depending on the measurement object. By increasing the signal-to-noise ratio (S/N ratio), this improves the reliability of measurements taken in coal combustion and other processes where there is high particulate loading. Designed to meet the requirements for SIL2 certification (certification pending) defined by the International Electrotechnical Commission (IEC), the TDLS8000 will play a key support role in ensuring the safe operation of plants.
  2. Improved operability and maintenance efficiency - The TDLS8000 comes with a large 7.5-inch LCD touch screen that can display a greater variety of data. The touch screen replaces the push button interface used with preceding models, making the setting of parameters easier and more intuitive. The light source module containing the laser diode is fully sealed and damage resistant. To facilitate troubleshooting and reduce downtime, this module is able to store up to 50 days' worth of raw data that can be accessed anywhere in the world by, for example, a Yokogawa response center.
  3. Compact size - The redesigned TDLS8000 is just three-quarters the size and weight of the preceding model, allowing it to be installed in a greater variety of locations.

Friday, June 30, 2017

Happy Fourth of July from Flow-Tech

"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, — That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness."

THOMAS JEFFERSON, Declaration of Independence

Thursday, June 29, 2017

Writing LabVIEW™ Programs for Brooks® Mass Flow Controllers (MFCs)

Brooks Instrument has been innovating thermal mass flow technology for decades, continually launching new products and enhancing existing systems to unlock new levels of thermal mass flow precision, responsiveness, accuracy and repeatability.

LabVIEW™ is systems engineering software for applications that require test, measurement, and control with rapid access to hardware and data insights. LabVIEW simplifies hardware integration so that you can rapidly acquire and visualize data sets from virtually any I/O device, whether by NI or a third-party.

Brooks® MFCs are known for:
  • Industry-best range of products to meet widest application needs
  • Innovative MultiFlo™ technology lets one device change gas types and ranges without removing the device from the system and improving actual process gas accuracy
  • Complete product range includes both elastomer sealed and metal sealed options
  • Ultra-high purity devices engineered to satisfy thin film, semiconductor and other high-tech industry requirements.
The video below provides step-by-step instructions on writing a LabVIEW™ program for Brooks Instrument MFC's.

For more information, visit http://www.Flowtechonline.com/Brooks. In Maryland call 410-666-3200. In Virginia call 804-752-3450.

Monday, June 12, 2017

New Product Alert: Release 4 of the SMARTDAC+ GX/GP Series Paperless Recorders and GM Series Data Acquisition System

SMARTDAC+
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:
  1. 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).
  2. 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.
  3. 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

To download brochures, visit this link. For more information inVirginia, contact Flow-Tech at 804-752-3450 or visit http://www.flowtechonline.com.

Friday, June 9, 2017

Yokogawa ROTAMASS "Total Insight" Line of Coriolis Flowmeters

ROTAMASS InsightIn the last decade, the use of Coriolis flow meters has been changing from general purpose to supporting your needs in specific applications.

While the technological complexity increased, the demand for simple operation and handling is also a rising requirement.

Yokogawa answers these needs by offering six dedicated product lines with two specialized transmitters allowing the highest flexibility - the ROTAMASS Total Insight.

Total Insight


The ROTAMASS philosophy gives Total Insight throughout the whole lifecycle.

To facilitate optimal processes and increase the efficiency of personnel, Yokogawa has placed a strong focus on simplifying fundamental operating concepts with Total Insight. The Total Insight concept is built in to the latest generation of Rotamass transmitters and provide enhanced settings for customized setups, pre-defined trend views, or multiple configuration sets for fast changeover in batch production are supported.

ROTAMASS NanoROTAMASS NANO - When every drop counts
The world's smallest dual bent tube Coriolis flow meter series for highly accurate measurement at lowest flows.
The dual tube design compensates for fluctuations of density, temperature, pressure and environment conditions. This provides a consistent repeatable and accurate measurement especially for small size Coriolis flow meters.
  • Typical Applications
    • Batching
    • Dosing
    • Blending
    • Chemical injection
    • Dosing systems
    • High pressure gases
    • Liquid and gas low flow measurement
    • Precision coatings
    • Metering pump control
    • Metrology
    • R&D laboratory
    • Vacuum thin film coating
ROTAMASS PrimeROTAMASS Prime - Versatile in applications
The favorably priced and versatile Coriolis flow meter with lowest pressure drop in the market. Ideal for a broad range of standard applications, this series is a flexible and cost effective solution for highly accurate flow and density measurements.
Features such as concentration measurement or the Tube Health Check function allow the meter to be adjusted to customer needs.
  • Typical Applications
    • Batching
    • Blending
    • Chemical recovery
    • Continuous reaction
    • In-line concentration and density measurement
    • Catalyst feed
    • Filling and dosing
    • Mass balance
    • Net oil computing
    • Palm oil
    • Process control
ROTAMASS SupremeROTAMASS Supreme - Experience meets innovation
The most accurate Coriolis flow meter with industry’s best zero stability.
The successful Rotamass series has been progressively developed and is also newly equipped with the latest technology. This meter delivers unsurpassed performance for demanding and critical applications with superior aeration handling and advanced diagnostic functionality.
  • Typical Applications
    • Batching
    • Burner control
    • Feed and product control
    • Filling and dosing
    • Gas void fraction
    • In-line concentration and density
    • Loss control
    • Material and mass balance
    • Net oil computing
    • Process control
    • Solvents
    • Water cut
ROTAMASS IntenseROTAMASS Intense - Safe under high pressure
The Coriolis meter with the most robust and durable design for precise measurement in high pressure applications.
Safety is always a concern and especially when operating at high pressures. Therefore, this series has been designed to meet the highest safety requirements. Combined with advanced diagnosis such as the “Total Health Check” function, operation is always under secure control.
  • Typical Applications
    • Chemical injection
    • Compressed gases
    • Fuels
    • Glycol TEG/MEG
    • High pressure gases
    • Hydraulic oil
    • Hydrocarbons
    • Liquified gases
    • Natural gas hydration
    • Offshore and onshore
    • Oil refinery processes
    • Solvents
ROTAMASS HygienicROTAMASS Hygienic - With pure dedication
Specifically designed and certified for food & beverage, biotechnology and pharmaceutical utility applications.
This series is the appropriate answer to the daily constraints of hygienic processes ensuring continuous product quality and minimizing losses. This is made easy by the provided multi-variable measurement and various dedicated features.
  • Typical Applications
    • Bioreactor feeds
    • Bottling
    • Carbonation of beverages
    • Deionized water
    • Fermentation
    • Juice processing
    • Molasses measurement
    • Online sugar concentration
    • Raw milk tanker unloading
    • Process water reclamation
    • Product quality control
    • Sugar industry
ROTAMASS GigaROTAMASS Giga - Big in performance
Delivering best in class accuracy and most flexible installation at high flow rates.
The unmatched accuracy at the low end of the measuring range offers maximum flexibility from engineering to final operation. This series unifies a long service life with low maintenance costs and reliable performance.
  • Typical Applications
    • Bitumen
    • Distribution networks
    • Drilling mud
    • LNG
    • Rail car loading
    • Ship loading
    • Truck loading
    • Tar
    • Offshore and onshore
    • Oil well cementing and hydrofracturing
Essential and Ultimate Transmitters

Future Ready. The ROTAMASS TI product family has a common and unified transmitter platform with two options that provide the highest flexibility and a tailor-made solution. The Essential transmitter is the cost effective solution for general purpose applications, and the Ultimate transmitter provides various additional features for best-in-class measurement.
Essential TransmitterEssential Transmitter
  • Wizard for easy setup and guidance through the main configuration
  • “Event Management” as unique and useful support to run the process effectively and safely
  • Data mobility provided by microSD card for easy transfer to other devices for fast setup or to pc for in-depth process analysis or remote service
  • Widest range of I/O combinations in the market for most flexible adjustment to the existing system periphery
  • Universal power supply to install the device anywhere in the world
  • HART communication
Ultamate TransmitterUltimate Transmitter
  • Patented “Tube Integrity” function and “TotalHealth Check” for inline meter verification without disturbing running measurements
  • “Features on demand” for easy expansion of special functions via software activation key
  • Batching function combined with multiple configuration sets to support fast changeover
  • “Dynamic Pressure Compensation” for consistently accurate and stable measurement even with significant fluctuations in operating pressures
  • Inline concentration measurement
  • Integrated net oil computing acc. API standard
For more information on ROTAMASS Total Insight in Virginia, visit http://www.flowtechonline.com or call 804-752-3450.

Wednesday, May 31, 2017

Heated or Chilled Water Concepts in Campus Metering Applications

Reprinted with permission from KEP

Typical Heated/Chilled Water Metering System Using Magnetic Flowmeter System, Two Temperature Transmitters and Electronic Flow Computer.

A typical modern, heated/chilled water metering system usually consists of several components:
  • Flow Meter installed in the line
  • A temperature transmitter mounted in the supply line to measure the supply temperature 
  • A temperature transmitter to measure return temperature 
  • A Flow Computer that will compute the energy flow 
  • An optional Data Logger/Modem that will monitor the customer site and provide trend information 
If remote metering is required, a remote PC, modem, and remote metering software may be used in conjunction with this.
Typical Heated/Chilled Water Metering System
Typical Heated/Chilled Water
Metering System with Flow Computer

Equipment Selection

The flowmeter is sized by the manufacturer based on the expected line size, fluid and flow rates anticipated in the application. This would normally require the line size, flow rate range and expected line conditions of temperature and pressure be known. The temperature transmitters are selected for a measurement range that will meet or exceed the range of temperature to be encountered in the application. The flow computer performs the necessary calculations needed to compute the energy flow (BTU’s or ton-hours) from the electrical signals being fed into it. The optional data logger and modem permit the remote monitoring of those signals and the data logging of the measured and computed values. A remote PC with modem can access the information either in the data logger or in the current readings of the flow computer.

Factory Calibration

The flow meter, flowmeter, the transmitters and the flow computer are calibrated by their respective manufacturer’s prior to being supplied to a utility company in accordance with the instructions provided when the units are purchased.

Installation

During installation the two temperature transmitters and the flow computer are installed in accordance with industry guidelines and manufacturers instructions.

The individual calibration and setup documents provided by the manufacturers are reviewed.

Startup

During startup the individual components of the systems are setup so that they operate correctly.

For the transmitters this will normally involve double-checking of each transmitter range and optional features using a hand held terminal.

The flow computer will be setup by entering the information on the flowmeter, and with the ranges of both temperature transmitters. In addition, the desired items to be included in the data logger will also be setup. This is usually done by the front keypad although connecting the device to a laptop and using an external, special program supplied by the manufacturer could also be used.

The setup of each individual input item is verified. For each measurement, there is a transmitter to scale and send an electrical signal to the receivers that need this information. The scaling of each transmitter must also be set into the corresponding flow computer input channel. If a change is made to one, it must be made to all.

The basic operation of the system can be verified by checking that the respective sensors are producing the correct signals, based on the observed signal, the flow range setup in the sender and receiver of the informa- tion, and the observed process conditions in the line. Signal simulators and multi meters may also be used.

When using voltage or current ranges for the flow input, there is a “low flow cutoff” that should be set to prevent the system from metering when no flow is present. This is also limits the low flow measurement range so it is usually set to the lowest practical value.

There is also a low temperature cutoff that can be used to prevent the false totalization of energy when small differential temperatures are indicated while recirculating water.

Meter Readings

Meters may be read either locally by taking a reading off the flow computer or remotely by taking a reading off the flow computer by modem or by reading the data logger or both. The operational status of the meter system is also checked periodically.

Servicing the Metering System

Often a utility will perform various inspections each year on each energy meter. Manufacturers of the compo- nents used in the system provide a number of service and test aids for Service personnel that permit them to interrogate a component to determine if it is operating properly. From time to time problems may occur in any system. The transmitters, flow computer, and data logger usually have some diagnostic capability and can assist in problem detection and notification.

If it becomes necessary, for any reason, the flowmeter may be changed out. This sometimes occurs when the heating load changes or the actual flow range is different than the expected range as a result of inaccu- rate sizing information. When a sensor change out occurs the information on the new flowmeter must also be set into corresponding transmitter and the flow computer flow input channel. If a change is made to one, the change must be made to all.

If a transmitter is changed by either replacement or re-scaling or re-spanning then the new scaling of that transmitter must also be set into corresponding flow computer input channel. If a change is made to one, the change must be made to all.

Most utilities remove portions of the meter system from service after several years for recalibration. The flow computer can usually be checked in place using simulators. They can be removed from service if needed and replaced with another device that then must be setup for use as described earlier. In other cases, the transmitters are replaced with a calibrated replacement unit.

KEP Flow Computer
Kessler-Ellis Products (KEP) offers the Supertrol 2 Flow Computer for Heated or Chilled Water Metering applications. It is available in a variety of housings to suite a wide range of application environments.

For more information on KEP products follow this Flow-Tech link or call 410-666-3200 in Maryland, or 804-752-3450 in Virginia.