Tag Archives: Flow Energy Measurement

The Perfect Biogas Flow Measurement Solution | Sierra Instruments

Solving the Biogas Flow Measurement Conundrum

In recent years, concern about climate change has increased interest in alternative energy sources, specifically in biogas energy.

Biogas energy can be extracted from landfills. Digester gas produced at wastewater treatment plants is another common form of biogas.

So why is it so popular? In a word, economy. This otherwise wasted biogas can be used for heating, electricity, or to fuel internal combustion engines—the possibilities are endless!

This, of course, has created a demand for biogas measurement solutions. Many flow meter companies have jumped into the biogas measurement market, but not all technologies can handle this tough application.

Let’s look at why biogas measurement is so challenging and how it can be best handled.

The Challenges

Accurate flow meter measurement is critical to optimal biogas energy collection, but these factors make it difficult:

Varying compositions

This is the biggest concern and the Achilles heel for many flow meter companies. Biogas composition can vary based on the source. Biogas typically contains about 55%-65% methane, 30%-35% carbon dioxide, and some hydrogen, nitrogen and other impurities.

However, a representative compositional analysis (in volumetric percentage), shown in Table 1, shows the wide ranges in methane composition between 50%-75% and carbon dioxide between 25%-50%. This represents how the biogas composition can change over time with changing conditions in the landfill or in the digester tank.

Table 1

Most flow meters are calibrated to measure one specific gas mix composition, and sending the meter back to the factory to be recalibrated every time there’s a change isn’t very efficient. In co-generation situations, facilities managers need to be able to depend on the accurate measurement of the biogas produced—in spite of varying gas composition.

Low pressure

Low pressure makes differential pressure devices, like orifice plates, unsuitable since they require a fairly large differential pressure to operate.


Biogas is often very dirty, with a high moisture and particulate content that can clog up devices like annubars and orifice plates and gum up turbine meters and similar instruments that have moving parts.

Energy Content

Biogas produced from landfills has an additional issue: energy content. The heating value of landfill methane can be raised through adding make up natural gas as seen in the image below. But accurate flow meter measurement is critical to the process of obtaining optimal heat value.

biogas 1

Many thermal flow companies have entered this renewable energy market, but few have been able to solve these issues. Specifically, how can they make their flow meters automatically adjust for changing gas compositions?

The answer is, they can’t. The meters must be sent back to the factory for recalibration.

The Solution

Fortunately, advancements in thermal flow meter technology have not only made composition management possible, but highly accurate as well. However, few flow meter systems are available on the market today that can account for variable biogas composition.

QuadraTherm flow meters can. With an innovative design that maximizes four sensors instead of the traditional two, QuadraTherm handles this application without the need for constant recalibration.


QuadraTherm meets the criteria for successful biogas measurement by managing changes in:

  • Gas composition
  • Gas mass flow rate
  • Gas temperature
  • Gas pressure
  • Outside temperature
  • Pipe conditions (size and roughness)
  • Flow profile

A Closer Look

QuadraTherm has moved thermal insertion flow meter technology into a realm of unprecedented accuracy. Readings of +/-0.75% of reading are now possible as opposed to the 2.0% readings of older thermal technologies.

Traditional analog measurement circuits, like the Wheatstone bridge, have been replaced with more powerful, hyper-fast microprocessors that run comprehensive flow-measurement algorithms to compute mass flow.

This proprietary algorithm set serves as the “brain” of the mass flow meter, using inputs from the four sensors to solve the first law of thermodynamics for the sensor in the biogas flow stream. This allows the precise calculation of heat convected away by biogas mass flow, providing accurate mass flow measurements in a fraction of a second.

This algorithm allows management of gas composition because now recalibration is not required every time the gas changes.

qMix Gas Mixing Software

The meter can hold up to four user-customizable gas mixtures onboard and store biogas composition in a proprietary gas library, easily accessed through user software called qMix™. Engineers and operators have access to this gas library, which contains all the gas properties needed to make algorithmic gas mass flow rate calculations.

Once sampling has determined the biogas composition, operators can use qMix™ to create and name a proprietary biogas mixture. This allows operators and engineers to use just one meter with one calibration for varying gas compositions, offering a major cost savings compared to continuous sampling devices

A Money-Saving Solution

Sierra’s QuadraTherm Series of mass flow meters is the perfect solution for successful biogas measurement in any environment. By eliminating the need for frequent recalibration, QuadraTherm can save companies thousands of dollars in calibration costs, shut downs and loss of gas monetization through loss of accuracy.

Download Whitepaper on Precise Biogas Measurement 

Bringing Energy Efficiency and Cost Savings to Veteran’s Facilities

va blog image

As the infrastructure of our Veterans Affairs (VA) facilities age and government-driven energy efficiency mandates rise, VA facilities’ engineers are faced with a decision to upgrade existing equipment or replace older equipment in order to improve energy efficiency. Dealing with the upgrade or replace decision is a big one. Replacing older equipment is costly, but in the end, newer technology may integrate better into automation systems and realize even greater cost saving in energy over the long haul. What kind of data do facilities managers need to make these critical energy-saving decisions?

The Best Place To Start-Ask the Right Questions

A great place to start is by getting accurate “flow energy” measurements of the methane/natural gas, water, and steam flow in your major operations, especially in boilers and steam flow systems. Flow energy is defined as “flows that cost money,” like natural gas, compressed air, water, and steam. Since none of these commodities are “free,” VA facilities managers must strive to measure their “energy” usage accurately, determine the processes that use the most energy, and make them more efficient either by upgrading or replacing the equipment.

  1. Is your boiler running at optimal levels?
    To assess the efficiency of your boiler’s combustion, it’s critical to get accurate inlet methane measurements. Once you have accurate methane measurements, you can answer the key question: Is my boiler running too rich or too lean? If your boiler is running “rich”, which means it is using more methane than is needed for optimal combustion, you not only waste money on natural gas costs but also emit more hazardous air pollutants into our environment-every molecule of methane that is not burned increases emissions. If you’re running too “lean”, your boiler is not at optimal combustion, so you are not producing steam at capacity. Once you have determined the health of your boiler, you can either make the decision to replace your aging boiler or use measurements from thermal mass flow meters to better tune your current boiler. Learn More about Boiler Efficiency.
  2. How much steam are your boilers producing? How much steam are you allocating?
    Efficient steam production is critical for optimizing energy at Veteran Affairs facilities. The steam produced by a boiler must be measured in order to determine boiler efficiency. Accurate steam flow measurements at the production point and key allocation points will give you a true assessment of how efficient steam is running through the facility and helps identify leaks in the system. Now the question becomes what technology provides the most accurate steam flow measurement? Traditionally, steam flow has been measured with a differential pressure device. This is typically an orifice plate. However, such devices are inherently volumetric flow measurements. Changes in pressure and temperature will change the mass flow rate of steam. Even a “small” change of 10 percent in steam pressure will result in a 10 percent error in non-compensated mass flow. This means that, in a typical differential pressure measurement installation, the volumetric flow rate measured by the device must be compensated by measuring temperature and pressure, and then these three measurements (ΔP, T and P) integrated with a flow computer to calculate mass flow.
    Insertion multivariable vortex flow meters allow one instrument and one process connection to simultaneously measure mass flow rate, temperature, pressure, volumetric flow rate, and fluid density. The density of saturated steam varies with either temperature or pressure, while superheated steam varies with temperature and pressure, so multivariable vortex flow meters assure the flow meter’s density calculations are correct, and therefore, mass steam flow measurements are correct maximizing your steam productivity. Multivariable vortex flow meters provide steam accuracy of 1 percent of reading, 30:1 turndown plus pressure and temperature compensation.Again, you may need to upgrade aging steam flow infrastructure or simply tune your system with accurate steam flow measurement to save on cost and fulfill efficiency mandates.
  3. How much water are you using for key processes?
    In boiler tuning, the feedwater flow to the boiler is an important measurement, since you need to measure the efficiency at which the boiler turns this feed water into steam.  You may also need to measure the thermal/BTU energy.  A clamp-on ultrasonic flow meter is ideal for this type of water measurement due to high accuracy at low and high flows, installation with no pipe cutting or process shutdown, and immunity to external noise. Coupled with temperature sensors on the “hot” and “cold” legs, the thermal energy gained or lost can be measured. This thermal/BTU measurement is critical for optimizing central heating and cooling systems that provide HVAC to the entire facility.

Big-3 Eases the Burden of Recommissioning  

To address the flow measurement of the methane, steam, and water for such a large scale equipment upgrade, Veteran Affairs facility managers would typically work with up to 5 different companies with varying technologies to get these critical flow energy measurements. Imagine only working with one supplier for all of your gas, liquid and steam flow measurements. Sierra provides flow experts and Big-3 technology for all gas, liquid, and steam flow measurements. The Big-3 includes:

  • QuadraTherm 640i/780i, the most accurate thermal flow meters on the market for methane and air flow measurement
  • Insertion mulitvariable InnovaMass 240i/241i vortex flow meters for steam flow measurements-easy hot tap installation
  • Clamp on InnovaSonic 207i ultrasonic water flow meters with energy/BTU capability
  • Specialized, local support team for all three technologies
  • Shared software applications and operating system for easy integration
  • Designed, built, and calibrated in the USA by Sierra

Learn more about Flow Energy Measurement of All gas, liquid, steam flow.

Watch Flow Energy Management Videos


Tune Your Boiler: Watch Video for 3 Tips to Improve Energy Efficiency

Improving energy efficiency in facilities, campuses and hospitals is top of mind for most facilities managers and engineers.  Government regulations like Boiler MACT and other energy efficiency mandates for government buildings like VA hospitals have put the pressure on facilities engineers to take a hard look at their equipment to optimize for energy efficiency.  Optimizing energy efficiency comes in the form of both saving energy and increasing productivity.  Hands down the biggest energy hog in a facility is compressed air production and a close second are the boilers which use methane & air for combustion to create steam energy.

Glen Coblentz, VP Sales North America for Sierra, tackles the tough question, “Is Your Boiler Running at Optimal Levels?” and gives some in the field tips to tuning your boiler to improve energy efficiency in his new Flow Tip Video. Watch Video.

3 Tips for Tuning Your Boiler

1. Know Your Flow-get accurate methane measurements in low and high flow conditions
As with most energy audits, it’s critical to know how much fluid you have running in your pipe. In this case, you must know much inlet methane (or intake fuel) is entering your boiler? This is actually a difficult flow measurement due to the requirement for flow measurement accuracy over a wide range, from very low flows to high flows. There are many types of flow technologies to choose from for methane measurement.

In the past, facilities have used insertion turbine meters for methane measurement, but turbine meters don’t work well with low flow conditions.  Thermal flow meters are the ideal technology for methane measurement due to their high accuracy over a wide range-from 0 up to 60,000 sfpm  (0 to 305 smps) and wide 100:1 turndown.

2. Get direct mass flow measurements over volumetric flow rate
We have established that thermal flow meters have excellent accuracy and turn down over a wide range. But what are the other advantages of using thermal flow meters for methane measurements? Thermal mass flow meters are ideal for natural gas combustion because mass flow rate, not volumetric, is the quantity of direct interest. For example, the optimal fuel/air ratio for efficient combustion is calculated on a mass basis.

Natural gas is also billed on a mass basis. Because thermal mass flow meters count the molecules of gas, they are immune to changes in inlet temperature and pressure. In a thermal flow meter’s simplest working configuration, fluid flows past a heated thermal sensor and a temperature sensor. As the molecules of the fluid flow pass the heated thermal sensor, heat is lost to the flowing fluid. The thermal sensor cools down, while the temperature sensor continues to measures the relatively constant temperature of the flowing fluid.

3. Determine if your boiler is running too rich or too lean 
Once you have accurate methane measurements, you can answer the key question: Is my boiler running too rich or too lean? If your boiler is running “rich”, which means it is using more methane than is needed for optimal combustion, you not only waste money on natural gas costs but also emit more hazardous air pollutants into our environment-every molecule of methane that is not burned increases emissions. If your running too “lean”, your boiler is not at optimal combustion, so you are not producing steam at capacity.

So the answer is to “tune” your boiler to get the optimal boiler efficiency calculation which improves energy efficiency.  A well-tuned boiler is around 80% efficient. If the boiler’s efficiency is less than 80%, then energy is being wasted.  Government regulations like Boiler MACT require end users to fix the boiler to meet this efficiency level. “Fixing it” entails fixing leaks, adding insulation, and cleaning heat exchanger tubes, which all add to the cost of boiler maintenance. Download Boiler MACT Information Guide.

Boiler Tuning with Thermal Mass Flow Meters

As part of Sierra’s Big-3™ suite of Flow Energy Management products for all gas, liquid, and steam flow applications,  QuadraTherm 640i/780i thermal flow meters have been specifically designed for precise flow energy management in compressed air and natural gas applications. QuadraTherm offers:

    • Direct mass flow measurement of gases, eliminating the need for temperature or pressure compensation
    • Wide 100:1 turndown
    • Accuracy of +/- 0.5 percent reading; high flows 60,000 sfpm (0-305 smps); 100:1 turndown
    • Multivariable Mass flow rate, temperature & pressure
    • Advanced four-sensor “dry sense” technology minimizes drift and enables field validation
    • Insertion version with hot tap capability for easy installation on large pipe
    • Software applications for easy set-up, in-situ calibration, dial-a-pipe, and gas mixing
    • Digital communications suite

For a more economical solution, Sierra’s BoilerTrak 620s provides direct mass flow accuracy at a lower price point. Sierra also offers all products needed for Boiler tuning like the InnovaSonic 207i ultrasonic flow meter to measure the feedwater and InnovaMass 241i for measuring steam output. Learn more about our complete flow energy management solution for all gas, liquid and steam flow applications.

See all of Sierra’s boiler efficiency solution flow meters.



Steam Flow Energy Measurement

From facilities management to district heating applications, accurate steam flow energy measurement is a critical flow measurement needed to incur substantial savings on energy and maintenance costs. However,  steam flow energy measurement is also the most difficult flow measurement to make due to the unknown factors of what type of steam is being produced, various pipe sizes, and difficulty in steam flow meter installation. In most cases, you need to shut down the steam production, which can cost thousands of dollars in lost productivity, to install the steam flow meter.

Glen Coblentz, VP Sales North America for Sierra, has over 30 years experience dealing with the challenges of getting accurate steam flow measurements in facilities. Learn some tricks of the trade in his new Flow Tip Video, “Do You Know Your Steam Flow Measurement?” He tackles 3 important questions for accurate steam flow measurement:

  1. What kind of steam is your facility making? Are they producing saturated or superheated steam?
  2. What type of measurement, mass or volumetric, provides the most accurate steam flow measurements?
  3. What do you do when you absolutely cannot shut down the process, but you find you need to measure steam flow?

Determine if your Steam is Saturated or Superheated Steam

To measure steam flow effectively,  you need to know what type of steam you are producing. Saturated steam and superheated steam are very different and measuring incorrectly for either one will cost you big time.

It may seem like this would be obvious, but let’s say you are creating superheated steam.  If you have to continually add lots of heat (energy) to the steam so that you can create the superheated steam you may have something wrong with your process. When you specify, your steam flow meter make sure you know what type of steam you are measuring as this determines how the steam flow meter is set up from the factory. Incorrect set up results in incorrect steam flow readings. The density of saturated steam varies with either temperature or pressure, while superheated steam varies with temperature and pressure, so multivariable vortex flow meters assure the flow meter’s density calculations are correct, and therefore, mass steam flow measurements are correct maximizing steam productivity. Sierra’s multivariable vortex flow meters provide steam accuracy of +/- 1% of reading, 30:1 turndown plus pressure and temperature compensation.

Use the Right Flow Meter Technology to Ensure the Most Accurate Steam Flow Measurements

While there are a multitude of steam flow measuring technologies out there, an insertion multivariable mass flow vortex meter will be your best option for accurate data to help make informed decisions about your steam flow system.

Unlike differential pressure devices commonly used for steam flow which are inherently volumetric flow measurements, a multivariable mass flow vortex uses mass flow as its basis of measurement. This is important,  because changes in pressure and temperature will change the mass flow rate of steam. Even a “small” change of 10 percent in steam pressure will result in a 10 percent error in non-compensated mass flow. This means that, in a typical differential pressure measurement installation, the volumetric flow rate measured by the device must be compensated by measuring temperature and pressure, and then these three measurements (ΔP, T and P) integrated with a flow computer to calculate mass flow.

Choosing an insertion multivariable vortex meter gives engineers the benefit of using one instruments and one process connection to simultaneously measure mass flow rate, temperature, pressure, volumetric flow rate, and fluid density.

When Shutting Down is Not an Option – Hot tap

In many facilities, a very real challenge is the need to measure steam flow but shutting down your process is not an option. So, what do you do in these situations?

The answer is to use Sierra’s 241i insertion vortex flow meter. Unlike other options out there, the 241i has full packing gland and hot tapping capability allowing engineers to insert the sensor into any size pipe they want, anytime they need to do so to make a steam flow energy measurement without shutting down the process.

    • Insertion probe up to 72 inches (2M); optional hot tap
    • Ideal for saturated or superheated steam, gas, and liquid
    • Low-cost alternative to Coriolis meters for large pipes and ducts
    • Easy single-point installation; hot tap and hot tap retractor available
    • Volumetric flow rate or mass flow
    • Multivariable for five measurements in one device with one process connection:
      • Mass flow rate
      • Volumetric flow rate
      • Temperature
      • Pressure
      • Fluid density
    • Complete suite of digital communications
    • Rugged, long-lasting design for the toughest applications; no leaks with all welded gasket-free flow body

Learn more about Sierra’s vortex volumetric flow and multivariable mass flow meters.

Discover how vortex flow meter works.

3 Tips for Avoiding Costly Mistakes in Water Measurement

Whether you are running a large municipal water facility or one of the over 37,000 rural water utilities in the United States, water usage rates and costs drive your decisions. For any water system, it’s critical to answer key questions like:

  • What’s your water usage and/or production?
  • How much water are you distributing or allocating?
  • How can you identify & fix leaks in the system

3 Tips to Avoid Costly Mistakes

  1. Identify Leaks in the System with Accurate Water Flow Meters
    In many older water systems, eroding pipes and mismanagement of water measurement data lead to suspicion of water leaks which signifies money dripping out of your water system. The only way to identify leaks in your system is to compare the total production of water flow to the total water flow of your allocated and distributed water. To get water flow data, it’s critical that you choose the most accurate and flexible water flow meter. Paddle meters, for example, are notorious for getting clogged thus skewing your water flow data. This inaccurate measurement could give you a false positive-showing you may have a leak but you are reacting to false water flow data.
  2. Reduce Maintenance Costs With Proper Equipment
    Maintaining a large or small water system constitutes a continual maintenance cycle of the complete water system including the water flow meters and fixing the leaky pipes. One way to reduce maintenance costs is to lower the total cost-of-ownership of your water flow meters by lowering the installation costs, downtime, and cost to stock spare meters. A local water company in Florida learned this the hard way. They were measuring their water flow with traditional magnetic water flow meters which is a solid technology but not very economical to purchase or maintain. They also stocked 10 plus “mag” meters as spare parts which became very costly, especially as the pipes got larger. When a mag meter needed to be replaced, facilities managers had to build a new spool piece and shut down the system for installation. These maintenance efforts cost this water company up to $10,000 for each water flow meter replacement.
  3. Select Clamp-On Ultrasonic Water Flow Meters to Reduce Costs
    This water company made the switch to clamp-on ultrasonic flow meters which lowered their initial investment, cost-of-ownership and provided flexible and accurate water flow measurement. The beauty of clamp-on ultrasonic flow meters is that there is no pipe cutting, no system shutdown, and flexible measurement options. Use one clamp-on ultrasonic flow meter at various locations to get your total allocation rate which helps to track down leaks and inefficiencies. Clamp-on flow meters also are easy to install and can fully integrate with water management systems through BACnet and other digital protocols.

Case Study: Ultrasonic Flow Meters Offer Big Savings in Carmel, California

Carmel Riviera Mutual Water Company is a rural water company serving 600 homes along California’s beautiful and rugged Big Sur coast. Historically, their estimated annual water loss through leaks, waste, evaporation and other losses was around 30%. The company budgeted almost $60,000 per year in initiatives to reduce these leaks, including labor and materials for surveys and expensive repairs.

Sierra’s Solution

In their efforts to expand operational efficiency, Carmel Rivera investigated using Sierra’s InnovaSonic® 207i Clamp-on Ultrasonic Flow Meter. It promised to help determine waterloss percentage, improve production efficiency, improve water quality (reducing back flush) and more accurately identify over-users. The versatility of the clamp-on flow meter made it a perfect tool for the small, often cash-strapped, water company. Simply clamp the sensors onto the outside of the water pipe and extremely accurate measurement was now possible–no need for costly system shut downs, pipe cutting and plumbing.

After six months of using the InnovaSonic 207i, Carmel Riviera found their actual loss rate to be only 12% of their production – uncovering an 18% discrepancy in original water loss estimates. The improved production and usage figures derived from the InnovaSonic enabled the company to significantly reduce their $60,000 annual maintenance and operations budget to target more funding on improving conservation and efficiency.

Here’s What Makes Sierra’s InnovaSonic 207i an Ideal Choice:

  • Highly accurate (+/- 0.5% of reading)
  • Reduces maintenance costs by providing accurate usage rates
  • One meter for pipes 2” to 200”
  • Clamp-on sensors are very easy to install with no pipe intrusions
  • Includes complete data logging and analysis tools

Download Tech Note

How to Choose the Perfect Flow Meter to Reduce Flow Energy Costs in Your Facility











It’s almost October and Fall is in the air. 2020 has turned out to be a tumultuous year and things seem to only be heating up. COVID-19 continues to be a daily factor in our lives, civil unrest is abundant, and the US economy remains volatile.

However, despite these obstacles, common among all manufacturing is a desire to optimize business processes, cut costs where they can, and keep the doors open while still providing the best possible service for their customers. A tangible way to do this is to focus on managing the flow energy in their facility to control costs, increase process efficiency, improve profits. And this all starts with providing facility operations managers and engineers the most accurate flow data to make informed, smart decisions about how to better manage the flow energy in their facility.

Here are some steps to identifying the flow energy applications in your facility, asking the right questions, and then specifying the correct flow meter for the fluid and application to get the most accurate flow measurement possible.

Step 1. Understand Your Plants’ Key Flow Energy Applications and Ask the Right Questions.

The key to getting the best data to manage your facility is to know your plants key flow applications. Common applications across many facilities are natural gas measurement, compressed air measurement, steam production, usage, and allocation, water and energy BTU measurement. The common denominator is all of these are flow processes that need its specific flow energy measured.

Application #1
Precise Natural Gas Measurement-Improve Boiler Efficiency/ Sub-Metering

Need to measure fuel gas flow over a wide range? A single thermal mass flow meter can measure very high flows at peak demand or very low flows during startup and shutdown to always assure the best fuel to air ratio in your burners and boilers. Additionally, thermal mass flow meters can help you to control natural gas costs with sub-metering that will deliver improved accuracy and substantial savings.

Key Questions to control costs and improve process

  • Are your boilers running efficiently?
  • What’s the inlet flow rate of natural gas to your boiler?
  • How can you accurately measure your flow over a wide flow range?
  • If temperature or pressure change in your line, how do you maintain an accurate flow rate?
  • What flow meter technology is best for natural gas measurement?

Application #2
Compressed Air Measurement-Identify Costly Leaks & Inefficiencies
Want to be convinced that the energy costs to generate your compressed air don’t go to waste? Thermal mass flow meters are ideal for detecting compressed air leaks. Due to their low flow sensitivity and compact insertion probe design, you can easily move from place to place to find and eliminate leaks when you see flow where there is no air demand.

Key Questions to control costs and improve process

  • How much compressed air are your air compressors producing?
  • How much compressed air is being allocated to other processes?
  • Are there compressed air leaks in the system?

Application #3
Steam Flow Measurement-Production, Usage, and Allocation
Concerned that pressure drop in your delivery system is affecting your steam flow? Multivariable vortex flow meters measure steam pressure, temperature and mass flow with one compact meter, so you have confidence your steam plant and delivery system are efficient.

Key Questions to control costs and improve process

  • How much steam are your boilers producing?
  • Is your steam pressure drop affecting your flow measurements?
  • How can you measure steam in large pipes without shutting down your operation?
  • When pressure or temperature change, how do you know if your steam flow measurement is still accurate?
  • How much steam are you allocating to each part of your facility or campus?
  • Do you have a steam leak?

Application #4
Water Measurement & Energy BTU Measurement-Optimize Energy Efficiency
Water supply and usage has a significant impact on costs. Measure every drop without cutting a single pipe with a clamp-on ultrasonic flow meters. Integrated temperature measurements know how many BTUs your hot or chilled water loop actually delivers.

Step 2. Find the Right Flow Meter to Accurately Measure Your Key Gas, Liquid and Steam Flows

This is easier said then done. With all the various applications, it is a challenge to find the right flow meters for these gas, liquid, and steam applications. Often many different technologies are needed depending on the type of fluid being measured and many different flow meter companies must be used. Dealing with different companies and technologies can be very time consuming, expensive, and ultimately frustrating.









Sierra has solved this issue with our Big-3™ flow energy management strategy. We manufacture one complete family of flow meters we call the iSeries which work as a team to handle nearly any flow application found in industry. They provide a complete flow solution spread across three technologies, Thermal, Vortex and Ultrasonic. They feature user friendly apps and share a common user interface, so facility managers don’t have to re-learn each meter.

Regardless if you opt for the Big-3 option or just pick and choose one or two types of technologies for your process, the meters should:

  • Have high Accuracy and repeatability
  • Ability to measure a wide flow range – meters than can measure low to high flows.
  • Have Digital Communications Options
  • Calibrated to NIST standards
  • Able to validate in the field for easy in-situ calibration ( thermal/ vortex meters)
  • Have the necessary capabilities to measure flow rates required by governmental regulations

Work with one flow energy management expert that can help ease the burden of specifying new meters and recommissioning.

Our Big-3™ flow energy management strategy gives managers a best case scenario to deal with one flow meter company to specify and support instrumentation for all your gas, liquid, and steam flow measurements. This means one point-of-contact for product specification (measurement goals, fluids, flow rate, turndown requirements, temperature and pressure) and installation, one operating system for easy integration, and one local support team over the lifetime of the product.

Sierra’s Big-3 includes:

Download Flow Energy Guide for additional details to managing flow energy in your facility.

Watch Flow Energy Videos to learn more about how to measure e air, gas and steam better in your facility.

Now Measure All Flow Energy In Your Facility — One Solution — Three Metering Technologies

oil and gas refineryFacilities managers at large facilities often have the challenging task of managing all the flow energy in their facility with the mandate from upper management to save money on energy costs. To accomplish this goal, it’s critical to get accurate flow measurement data of the flow energy in your facility such as: natural gas, compressed air, steam, chilled and hot water.

The next challenge is to find the right flow meters for these gas, liquid, and steam applications. Often many different technologies are needed depending on the type of fluid being measured and many different flow meter companies must be used. Dealing with different companies and technologies can be very time consuming, expensive, and ultimately frustrating.

Sierra is tackling this issue with our new Big-3™ flow energy management strategy. Sierra now offers facilities managers a “one-stop shop” for all flow meters needed for effective flow energy management—all made in the USA and supported globally by our network of over 150 locations in over 50 countries.

We design and manufacture thermal mass flow meters for accurate compressed air and natural gas measurement, vortex shedding flow meters for steam and water measurement, and transit-time ultrasonic flow meters for liquid flow measurement. Product commissioning and training, lifetime tech support, and a global network of flow experts from one company make it easy to install and operate all gas, liquid and steam flow meters.

In addition, for easy integration into your facility, Sierra’s “Big-3” thermal, vortex, and ultrasonic (TVU) flow meters have:

  • Sierra’s commitment to great sensors with lifetime warranty—over 40 years of flow meter innovation and expertise
  • Shared firmware platform—Raptor OS operating system
  • Shared software apps for ease of use, so no learning new software and local display interface menu structures for each device
  • Major focus on excellent, fully automated, calibration facilities
  • Broad application capability (gas, liquid, steam)
  • One company, one point of contact for all three flow metering technologies
  • All designed, built and calibrated by Sierra in Monterey, CA USA

Watch Video

Let me explain more about Sierra’s new Big-3™ strategy and how it can help you transform your flow energy measurement strategy by watching this short video.

Download the Big-3 overview brochure.

Avoid Common Flow Meter Installation Mistakes to Optimize Flow Meter Performance

In our last blog, we discussed how plant and operation managers are searching for ways to manage the flow energy in their facility to cut costs and increase their process efficiency.

After the purchase decision is made, correct installation and calibration are the next steps to maintaining the equipment over the lifetime of the product and lowering the cost of ownership to increase the cost savings of the facility overall.  Let’s look at three common installation mistake to avoid and other ways to ways to lower cost of ownership and optimize your flow meters’ performance.

Avoid Common Installation Mistakes

Once you have identified the right flow meter for each type of fluid and application, proper installation of your flow meter is critical for successful flow readings.  Many times, if you think your flow meter “doesn’t work,” it could just be that the meter was not installed properly.  Here are some installation tips for thermal mass, vortex, and ultrasonic flow meters:

  1. In order to achieve accurate and repeatable performance for thermal mass flow meters, install the flow meter using the recommended number of straight-run pipe diameters upstream and downstream of the sensor. The chart below shows basic good plumbing practice for common upstream obstructions and meter locations.

Another solution for insertion flow meters is to install flow conditioning plates in the flanges somewhere in the straight section, requiring three diameters of pipe run (two before, one after). This installation will totally disrupt the flow, creating a “flat” profile.

2.  Avoid the following mistakes when installing vortex flow meters:

    • Not having the proper upstream and downstream diameter. Unlike thermal flow meters, vortex meters do not work with flow condition plates, so they must have a straight run of pipe to function at optimal levels. In most installations, you need a straight run of at least 10 diameters upstream and 5 diameters downstream.
    • Installing the vortex meter backward. When installing a vortex flow meter, make sure the orientation of your meter is in the direction the flow, so your meter’s flow sensor can measure your fluid accurately. Most vortex flow meters have some type of flow direction indicator to help you point downstream.
    • Measuring the incorrect fluid type in the pipe. In some situations, an end user might be measuring steam flow and think they are producing saturated steam, but in fact, they have a 50% over heat and are measuring superheated steam. (add link to blog explaining this)
    • Don’t shutdown your steam flow to install a vortex flow meter. Many insertion vortex flow meters have a retractor to make hot tap installation much easier. This means you can install the insertion vortex flow meter in large steam pipes with no process shutdown.

3. For ultrasonic flow meters, consider clamp-on sensors for field flexibility and offer for easy setup. With a portable ultrasonic flow meter, you can use one in several locations throughout your flow process. Fieldwork calls for flexibility in your equipment. Look for a liquid flow meter clamp-on sensors with a high-powered ultrasonic pulse and digital signal processing that requires just one set of transducers for a wide range of pipe sizes and materials like metal, plastic, and concrete.

In-Situ Calibration Increases Throughput & Avoids Costly Shutdowns 

The measurement accuracy of your device is critical in determining efficiency, performance, and cost-savings. So the more accurate your flow meter is the better data you have to make cost saving decisions.  Thermal mass flow meters with in-the-field in-situ calibration validate the meter’s accuracy without shutting down the facility. Learn how In-Situ calibration works in this video.

Learn more about how to manage the flow energy in your facility.

Download Flow Energy Guide for additional details on managing flow energy in your facility.

Watch Videos on how to measure air, gas, and steam better in your facility.





How Does a Flow Meter Work?

A flow meter works by measuring the amount of a gas, liquid or steam that passes through or around the flow meter sensors. While flow meter sensors work in many different ways, the end goal is the same: Deliver the most accurate and repeatable flow measurements for the specific application, whether for general research, process control or semiconductor processing.

Flow meters measure either mass or volume. In a volumetric flow meter, the flow Q is equal to the cross-sectional area of the pipe, A, and the velocity of the flowing fluid, v:  Q = A * v. In a mass flow meter the mass flow can be represented this way (where Q is the volumetric flow rate and ρ is the fluid density): ṁ = Q ∗ ρ

In many cases, especially in chemical reactions, combustion, or buying and selling gases, mass flow rate is the most important consideration.

How Different Types of Flow Meters Work

  • Capillary Thermal Mass – Uses thermal heat transferred between gas flowing in a very small tube (the capillary) and a set of resistance temperature detectors (RTDs) to measure gas mass flow.
    capillary flow
  • Immersible Thermal Mass – Uses thermal heat transferred from a heated sensor that is immersed in the flow to measure gas mass flow.
    diagram of how a thermal flow meter sensor works
  • Vortex Shedding – Uses vortices shed from a sensor immersed in the flow and a computed fluid density to measure volumetric and/or mass flow of gases, liquids and steam.
    vortex image 1
  • Transit-Time Ultrasonic – Uses ultrasound to measure the speed of a fluid flowing in the pipe to measure volumetric flow and can be clamped onto the outside of the pipe so no pipe cutting is required  

How Will the Flow Meter Be Used?

The next step is to determine what the flow meter is being used to measure:

  • Gas, liquid or steam?
  • Very large flows or only small flows?
  • High or low temperature and pressure of the gas, liquid or steam in the pipe?
  • Gases, liquids or steam flowing in big or complicated piping arrangements?
  • Costly products that must be measured very precisely?

Depending on the answer to these questions, the best flow meter working technology can be selected. Some flowmeters work better when measuring different things.

  • Thermal mass flow meters can precisely measure mass flow of gases from low to high flows.
  • Vortex Shedding flow meters are ideal for measuring liquid and steam flows at high temperatures and pressures.
  • Transit-Time Ultrasonic liquid flow meters are ideal for water or other liquid flow metering when no pipe cutting and process shutdown is ideal.
  • Older technologies such as differential pressure, positive displacement or turbine meters also have their place.

For a full explanation of how these various industrial flow meters work, visit Sierra’s industry application resources page where you’ll find application stories, white papers, videos and selection tools that will help you select the best flow meter for your application.


Five Ways QuadraTherm Flow Meter Technology Makes You And Your Process Smarter

For engineers and facility managers looking at their production operations to improve process efficiency, reduce costs, and find ways to meet sustainability and environmental governance regulations, selecting the right thermal mass flow meter with accurate flow measurement is critical. 

Utilizing a flow meter that lacks the capabilities to accurately measure your gas flow in your application results in a multitude of issues and ultimately cost more money down the road. These pitfalls include:

  • Poor accuracy and ongoing sensor drift results in inferior data
  • Utilizing more than one device to measure temperature, pressure, and flow results in increased installation costs, potential down time, and maintenance costs
  • Flow conditions and gas compositions can change over time. These changes will impact the meters ability to report accurate information. Is your meter equipped to handle these modifications without having to be sent back to the factory?

5 Ways QuadraTherm 640i with qMix Makes You and Your Process Smarter

How can instrumentation make you smarter? We get that accurately measuring flow is tough. You can’t see flow, but you know it’s there.

Most flow meters on the market are so restrictive in terms of their application parameters. It’s got to be the right pipe size, calibrated for specific gases for a specified  full-scale range.

QuadraTherm   technology allows you to change anything you want in the field-making your job easier and your process smarter.

Sounds too good to be true? Let us break it down for you.

#1 World’s Most Accurate Thermal Flow Meter

Achieve extreme precision with “percent of reading” accuracy rivaling accuracies of Coriolis technology over a wide flow range up to 60,000 sfpm (305 smps).

  • +/- 0.5% of reading (inline)
  • +/- 0.75 of reading (insertion)
  • Industry’s only ultra-low flow calibration from 0 to 499 sfpm or any value between for any pure gas or gas mixture
  • 40-point calibration available for highest accuracy

Bottom line: Your gas flow measurement will have precision accuracy, so you know what’s running through your pipe, even if that gas composition changes.


#2 Patented 4-Sensor Technology

Different molecules of gas transfer heat at a different rate, so sensor technology and stability is critical for accuracy.

  • Four-sensor technology provides the critical inputs for the Raptor OS’ living, learning algorithm used in the qTherm brain
  • Three platinum temperature sensors and one patented DrySenseTM mass velocity sensor
  • Eliminate drift with DrySenseTM sensor technology
  • Lifetime limited sensor warranty

QuadraTherm’s patented 4-sensor technology is the physical aspect of how we make the direct mass flow measurement to provide precision accuracy.

#3 qTherm “Brain” Optimizes Field Intelligence

qTherm “brain” manages changes in gas, internal and external temperature, and pressure via a comprehensive heat transfer model using only true variables which instantly calculate precise, stable and accurate mass flow measurement.

  • Solves the first law of thermodynamics
  • Enables Dial-A-Pipe
  • Insertion – adapt to any pipe size 2 inches or greater and pipe roughness
  • Inline – built-in flow conditioning eliminates straight run requirements

#4 qMix Manages gas Composition Changes

  • Use qMix software to easily create pure gases or any gas mixture in the field and retain accuracy – no additional factory calibration necessary
  • Meet EPA emissions regulations like “Quad O”
  • Dial-A-Gas
    • 3 gas slots for any gas or gas mixture you want; air comes standard
    • Accommodates multiple full scales for same gas or gas mixture
    • Capable of increasing full scale by 2x
  • Use “My Gases” Library to store unlimited new qMix gas compositions
  • qMix RealTime Flare Management System (FMS) Delivers Real-Time Flare Gas Measurement:
    • qMix RealTime app connects, reads and updates new flare gas composition from a GC-real time, no recalibration needed
    • Meet EPA rule 40 CFR 63-measure flare gas down to 0.1 sfps (0.03 smps) where ultrasonic flow meters can’t operate
    • Easy to install with current ultrasonic flow meters, no process shutdown

#5 World-Class Flow Calibration Ensures Accuracy

How your meter is calibrated matters.

  • Advanced gas loop delivers highest accuracy
  • Specifically designed for industrial thermal calibration – Over $2 million invested
  • Closed gas loop with pressurization, temperature control and NIST traceable calibration standards
  • Calibrated full scales up to 30,000 sfpm, any gas or gas mixture
  • Calibrated full scales up to 60,000 sfpm with slight de-rate of accuracy for any gas or gas mixture

Additional beneficial features

  • No moving parts
  • Hot-tap for easy install-no process shutdown
  • InSitu calibration with the ValidCal app validates original calibration in the field
  • Digital communications available
    • HART, Modbus, Fieldbus
  • Approvals available cFMus – Explosion proof for Class 1, Div 1, Groups B,C,D
    • CE – European Conformity
    • ATEX/IECEx
    • Canadian Registration (CRN number)
    • GOST R
    • Chinese Pattern

Discover more about QuadraTherm technology and how it can help you in your process by downloading the QuadraTherm Tech Guide.

Want to learn even more? Watch these great videos featuring QuadraTherm technology:

Take Control of Your Facility’s Flow Measurement

How to Achieve Maximum Boiler Efficiency

Breakthrough in Flare Gas Measurement

qMix RealTime Flare Measurement System – How it Works