Tag Archives: Applications

Three Easy Steps to Leak Testing with a Gas Mass Flow Meter

Leak detection can be easy, but in the “good old days” (which some of us may still be living in today), leaks were time-consuming to find and fix. Let’s compare how to find a leak the hard way, and then I’ll show you how easy it can be to automate the process with a mass flow meter.

Detecting a Gas Leak the Old-fashioned Way

Assume you have a product that must not leak. Leak detection can be performed by filling the device (a positive shut-off valve, for example) with a given amount of pressure, as measured with a pressure gauge or transducer. You would then shut off the flow and watch the pressure indication over a period of time to determine if the rate of ‘pressure decay’ is an acceptable amount or not.

That works fine, but it can be very time consuming, depending on the volume of the device and associated plumbing. And, if the test time is too short, the target leak rate too low, and the decay not large enough to get an accurate pressure reading, the results can be erroneous.

Three Steps to Easy Gas Leak Detection with a Gas Mass Flow Meter

Using the same example above where a shutoff valve is the device under test (DUT), let’s see how leak testing is performed with a digital gas mass flow meter.

  1. Put a mass flow meter in series with the DUT. This might cost more initially, but will pay for itself in the long run via improved quality and throughput.
  2. Fill the DUT with gas using a bypass line around the mass flowmeter.
  3. Shut off the bypass line once the valve has reached the proper pressure. The mass flow meter is so sensitive to even the smallest gas flows at the molecular level, you can almost immediately pass/fail  the DUT to the specified amount of allowable leak-by.

Automate Gas Leak Detection with a Digital Mass Flow Meter

Many of our customers choose to further increase their throughput by automating their leak detection system using a Sierra’s Smart-Trak mass flow meter and controller with a Compod programmable control module.

gas leak detection

Sierra Instruments offers a complete line of economical air flow meters, premium digital mass flow controllers and analog mass flow meters. Any of them can help you detect gas leaks quickly and precisely.

Economic OEM Mass Flow Controller for PVD Applications

Those of you who work in the solar energy and semiconductor industry will be familiar with physical vapor deposition (PVD) or sputtering that is commonly used for creating films of material on a substrate in the solar energy and semiconductor industry.

In the PVD process, a negatively charged electrode is slowly disintegrated by molecular bombardment. The PVD medium is typically argon because this gas generates sufficient momentum to free atoms from the target. In a vacuum environment, these free target atoms deposit themselves on the surface of the material and form the desired coating or plating.

Maintaining a specified gas mass flow rate to the vacuum chamber is critical during the PVD process. Typically, vacuum pumping stations require a throttle valve or orifice-limiting device to control the pump’s output when the PVD gas is introduced. This method is extremely pressure sensitive and can result in inefficient gas delivery and poor product quality.

PVD presents two critical challenges in the manufacturing of films used in solar photovoltaics. The first is the use of high vacuum. Since there is so little pressure drop to work with, PVD processes require flow control devices that are relatively insensitive to the absolute pressure in the chamber. This rules out devices like orifice plates that require a large pressure difference to operate efficiently.

The second issue is maintaining very precise gas mass flow rates. Since the layers deposited by PVD processes can, in many cases, be only molecules thick, very precise delivery methods of the doping gases are required.

At Sierra Instruments, we are in tune with these challenges and offer a solution for both: the Smart Trak® 50 digital flow meter. The instrument automatically compensates for changes in system pressure (vacuum pump fluctuations) or loss of pressure from the gas source (cylinder depletion). The SmartTrak 50 delivers a precisely controlled gas mass flow rate to the vacuum chamber to maintain high quality end-product.

Whether you’re a machine builder, systems integrator or end-user, our family of economical/OEM mass flowmeters and mass flow controllers provide a comprehensive mix of flow solutions for nearly every application type.

Part 3: Biogas Flow Meter Measurement-The Solution

In recent weeks, I’ve shared some exciting advancements in the biogas industry in regards to renewable energy management. From harnessing biogas energy from landfills to the digester gas produced at wastewater treatment plants, one thing is paramount: Adjusting for changing gas composition is critical to obtaining accurate flow meter measurement for optimal biogas energy collection.  Many flow meter companies want to play in this growing market, but few can solve the inherent problem: How can the flow meter automatically adjust for changing gas compositions without recalibration? In this final biogas post, I’ll share how Sierra’s innovative flow meter design has revolutionized the biogas industry, making the need for constant recalibration a thing of the past—thanks to a design that maximizes four sensors instead of two.

The Solution: Flow Meter Technology for Changing Compositions

Sierra’s four-sensor QuadraTherm technology 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.

QuadraTherm Thermal Flow Meter

Along with this new 4-sensor technology, traditional analog measurement circuits, like the Wheatstone bridge, have been superseded by 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 4 sensors, to solve the first law of thermodynamics for the sensor in the biogas flow stream, allowing 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.

Powerful Flow Meter Combination

By combining four-sensor technology with this algorithm set, the meter has the capability to change gas and compositions without losing accuracy. This new technology creates many benefits:

  • 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.
  • 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 a simple software tool 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.

Four-sensor thermal technology: Highly adaptable
The 4-sensor quadratherm mass flow meter pictured in  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

These changing conditions can all be managed with accurate readings without sending the flow meter back to the factory for recalibration, reducing downtime and saving money. Traditional two-sensor thermal flow meters need to be sent back to the factory for recalibration each time the gas composition changes or the application specification changes. This means that during the lifetime of the product, thousands of dollars will be saved in calibration costs, shut downs and loss of gas monetization through loss of accuracy.

The result is Sierra’s QuadraTherm Series of mass flow meters, perfect for successful biogas measurement in any environment. Tell us in the comments below. And be sure to read our free white paper download on Precise Biogas Measurement.

How have you solved the problem of precise biogas measurement with changing gas composition?

4 Keys to Great Portable Ultrasonic Flow Metering

The liquid measurement market is an extremely large market with many varied measurement requirements. To get the best bang for your buck, a portable ultrasonic flow meter is a practical solution. With a portable ultrasonic flow meter, you can use one liquid flow meter in several locations throughout your flow process.

Water FlowThere are many portable flow meters on the market, but you should specify a portable ultrasonic flow meter that delivers ease of operation, field and data flexibility while also providing highly accurate measurement results.

In this week’s post, I’ll share what characteristics to look for when selecting the right equipment for your field application.

1) Ease of Transport/Setup

Because of the portable nature of the flow meter, your equipment should all fit in one carrying case. This makes transport from one location to the next painless.

Look for portable flow meter with a complete measuring kit which includes:

  • Carrying case included
  • Non-invasive clamp-on transducers
  • Compact mounting racks (magnetic and cable mount) and coupling compound
  • Fast set-up—5 minutes or less! With easy set-up CD.

2) Field Flexibility

Field work calls for flexibility in your equipment. Look for a liquid flow meter with a high-powered ultrasonic pulse with digital signal processing that requires just one set of transducers for a wide range of pipe sizes and materials like metal, plastic and concrete. These baseline features allow you to use your portable ultrasonic flow meter for many different applications, pipe sizes, and material in your process. As a result, there is only one instrument to master for many different flow measurement needs.

3) Data Flexibility and Acquisition

What you need most from your liquid flow meter is accurate and flexible data.  Hand-held devices allow users to easily and quickly program the menu, including instantaneous flow rate, positive total, negative total, net total, velocity, date & time, and daily flow results. Wireless Bluetooth-enabled android tablet PC devices make it even easier to control data acquisition and processing.  With large amounts of data collected, a 1GB SD memory card promises high-capacity data logging.   Look for these wireless and handheld features to make your life easier.

4) Long Battery Life

You’ve reached your destination, you have your equipment set up to begin taking measurements—and your flow meter is unresponsive. There’s nothing worse than dealing with equipment that doesn’t function as it should when you really need it to. To solve this common problem, look for a portable ultrasonic flow meter that  includes a rechargeable lithium-ion battery that supports continuous operation for a minimum of 16 hours. You need a flow meter for those long days in the field.

Sierra has a line of portable ultrasonic flow meters that has all four of the characteristics described above.  Have questions about selecting the right flow meter for your application? Find a Sierra Rep in your area today.


Video Series Highlights One-Minute Flow Measurement Tips

At Sierra, we get very excited about flow measurement and control as you can imagine, and sometimes we want to spread the information we have quickly without a whole lot of fuss. That’s the spirit behind our video series called “Minute Flow Tips.”  In just a minute or so, we discuss a specific flow application and recommend best flow measurement practices.  The videos cover a variety of flow measurement control tips to help you strengthen your flow measurement capability to improve your overall process quality.

The “Minute Flow Tip” videos are available on our YouTube channel. Subscribe to the Sierra Instruments YouTube Channel today so you don’t miss out.

The first Minute Flow Tip video tip we ever published is below. Watch now!

Minute Flow Tip: Steam Measurement in Large Pipes


Need more information on measuring steam? Learn more about maximizing steam productivity and reducing overall cost of ownership for additional energy savings when measuring steam.

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 Achieve Vapor Mass Flow Control with a Thermal Mass Flow Controller

I often get asked to describe the most challenging flow meter applications that Sierra has successfully handled. One that comes to mind is how we used a capillary thermal mass flow controller (designed to measure gas) to accurately control a liquid used in the semiconductor industry at extremely low pressure differentials of about 10 Torr.

Originally, I thought there was no way this could work because the liquid causes the capillary thermal sensor maximum output or “rail,” and the pressure differential is way too low for 5 SLPM equivalent N2 flow. But wait, it actually does work! Here’s how…

The liquid is bubbled in a vessel by heating it to 80°c and pulling a vacuum; this turns the liquid into a vapor. Then, it must be kept under vacuum and at 80°c to prevent it from condensing back into a liquid. And, if it stays a vapor, the sensor can detect it as non-condensing gaseous flow and not rail out. This means the flow body of the mass flow controller needs to also be externally heated to 80°c.

The next step is to deal with the pressure drop. With a normal sized orifice in the valve to choke down and control the flow, the vapor would condense and turn back into a liquid, causing failure. The pressure drop would be much too high to achieve full-scale flow. The solution was to take a low flow meter body and match it up with a high flow valve typically used at up to 500 SLPM.  This provides a low enough pressure drop to reach full scale flow and does not cause the vapor to condense back into a liquid.

At Sierra, we are always striving for flow meter innovation and love to tackle tough stuff like vapor mass flow control. What can we do to help you? What’s your most challenging flow meter application? Share it in the comments below or contact us for advanced engineering support.

Out in the Cold: Mass Vortex Flowmeter Conquers Cryogenic Fluid

Cryogenic fluids are key in a variety of industries with very low temperature applications, including medical, large-scale frozen food processing and electric power transmission. However, these fluids must be handled – and measured – with great care, which can be a challenge if you’re using a traditional turbine meter or other tools to assess various fluid properties.

Wouldn’t it be nice if a single flow meter could do it all? Let me introduce you to one that can: the InnovaMass® Multivariable Mass Vortex Flowmeter, with technology that can simultaneously measure FIVE process parameters at the same time – mass flow rate, temperature, pressure, volumetric flow rate and fluid density.

We’ve extensively tested and field validated the extreme low-temp version of these flow meters over the last several years and have learned that most customers prefer the InnovaMass over turbine meters for measuring mass flow rates of cryogenic liquids down to -328°F (-200°C).  Using a special cryogenic temperature RTD, mass calculations are done with the latest density equations of state for liquid oxygen, nitrogen, argon and carbon dioxide. All models are fully field-programmable and configurable, and they feature RS485, MODBUS or HART protocols.

If you’re looking for a better way to measure cryogenic liquids, consider giving the InnovaMass flowmeter a try.

Insertion Flow Meter Straight Run Requirements

You have specified the correct industrial Thermal insertion mass flow meter and received your brand new meter. Now what? Where do you install the meter for optimal performance? This is where technical expertise comes in, along with a mixture of science and tribal knowledge.  In fact, Sierra has talked for years about a flowmeter being only as good as how it was calibrated, well, it’s also only as good as its installation.  In our technical support department, the primary installation question we get is: How much upstream and downstream straight run is required and what happens if you use less straight run?

Select an installation site that will minimize possible distortion in the flow profile.  This is because valves, elbows, control valves and other piping components may cause flow disturbances. Check your specific piping condition against the examples shown below. In order to achieve accurate and repeatable performance, 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.

What happens if you use less run than recommended?
Remember first that a thermal insertion mass flow meter probe is a “point-velocity” device and is only as good as the installation. It measures a velocity at a single point and then the electronics multiply by the cross-sectional area to arrive at a flow rate.

The meter takes into consideration an average shape of the moving gas as it goes down the pipe. It assumes a fully-developed, bullet-shaped flow profile that is being measured at the highest velocity point at the leading edge, center.

In the case of an expansion fitting upstream (like Example 5 in the chart), the danger is a “jet-stream” of gas shooting through the new, larger diameter section, that has not yet spread out uniformly.

It is not possible to predict what will happen, nor to place a de-rated accuracy on the results. The results would most likely be noisy from the turbulent, tumbling gas. Again – can’t be exactly predicted.

My suggestion is to install it with 4/5 of the straight run ahead, and 1/5 after, and move the probe around, in and out, to come up with a map of the flow pattern. Hopefully, the largest flow will still be in the center, dropping off uniformly in both directions by about 15%.


Flow Conditioning is Optimal Solution

Another solution for insertion flow meters is to  flow conditioning plates in flanges somewhere in the straight section, requiring 3 diameters of pipe run (2 before, 1 after). This installation will totally disrupt the flow, creating a “flat” profile.  The center point is now representative of the entire flow and the meter will do a straight multiplication without accounting for a drop-off at the edges.

The best solution for constrained piping environments is to specify an inline thermal mass flow meter with integral flow conditioning elements inside the flange body.  Watch this video to see how it works.

If this method is chosen, Sierra will calibrate the meter and flow conditioning all as one system assuring your readings will be more reliable and believable.

What are your biggest installation challenges? We would love to hear from you.



How to Save Time & Money by Calibrating Flow Meters Onsite

If you have hundreds of mass flow controllers and meters or just a few in your lab, facility, or manufacturing process, how do you keep up with the demands of annual recalibration? Most flow meters and controllers need to be recalibrated yearly to meet stringent ISO quality standards. This requires technicians to remove the mass flow meters from the process, send the products back to the factory for calibration, wait 4-6 weeks for the products to return, and complete tedious paperwork. The task of managing this calibration process is not only very time-consuming, but costs facilities and labs thousands of dollars in downtime and maintenance costs.

There is actually an easier, faster, and more cost-effective way to keep up with your yearly calibration of mass flow meters and controllers. Bring precise, primary standard calibration directly to your lab or process! How is this possible with the traditional factory recalibration process? Portable, gas flow calibration systems based on primary standards are the solution.

In this week’s post, I’ll share the key selection criteria for  choosing the best gas flow calibrator for you application and highlight the key applications for our  CalTrak family of gas flow calibrators.

Selection checklist for Gas Flow Calibrators

  • Primary Standard. Primary Standards are characterized by the basic quantities of time and distance, rather than against another gas flow meter, and can also be verified by every national laboratory by checking those basic quantities. The CalTrak line provides primary NIST traceability and is manufactured under strict ISO 17025 certification.
  • Portability. Battery-operated models allow for fast, accurate calibration in the field. So, bring your gas calibrator to your mass flow controllers on the factory floor and calibrate on location.
  • Flexibility. Easy-to-use interface and CalTrak Software captures flow data for export into a PC or Microsoft environment.

CalTrak Gas Flow Calibrator Video

To give you a better understanding of the importance of Primary Standards, as well as an overview of the CalTrak family, watch the following video.

Need help choosing the right gas flow calibrator for your application? Check out our Primary Standard Flow Calibration System Selection Chart. And, be sure to check out our sub-metering infographic to find out the secret to slashing your facility’s natural gas bill by thousands.