One of the Alicat Mass Flow Controllers at a water treatment plant which solved a big failure problem.

A regional water treatment plant feeds ammonia gas into their water system—in precise doses with chlorine—to sanitize 60 million gallons of drinking water per day. But their controllers (not from Alicat) were breaking due to an ingress of liquid ammonia. The problem was the thermal differential sensors inside the meters. The sensors in ordinary thermal MFC’s are programmed to raise the gas temperatures to a specific range. Liquids conduct heat better than gases, and the presence of even a small amount of liquid rapidly cools the elements inside. Detecting the drop, the temperature regulator will draw more and more power to heat them back up—quickly frying the electronics.

Accidental liquid in a gas flow controller can happen from many causes. Environmental monitoring stations take measurements in all kinds of weather. Rain, condensation, and melting snow are all potential sources. Fuel cell systems produce moisture by mixing oxygen and hydrogen in their process, a situation fraught with risks for accidental exposure. Or, a fluid tank that’s getting gas sparging may have a backflow event.

There is a cure

Getting liquids inside an Alicat leaves you in a far better state. Unlike thermally-based instruments, Alicat flow meters and flow controllers operate on the principle of differential pressure. Inside the instrument, gas flow turbulence is eliminated by a structure that creates laminar flow, and the difference in pressure between the two ends of the laminar stack is measured.

The water treatment plant got tired of buying new meters every time fluid got into their devices. They replaced their thermal instruments with Alicat meters. Now, when the liquid ammonia gets into their meters, they simply purge the system with a high-pressure flush of ammonia gas, then resume their sanitizing process.

Dry it out

If your Alicat meter/controller gets liquid into it, don’t delay. Liquids may cause the dissimilar metals to interact if left inside too long. If you can, put the assembly under vacuum conditions. We recommend a hard vacuum (0.25 psi or less) and some gentle heat (50° to 60° C). Together, they will encourage the liquid to evaporate out of the small channels in your instrument.

If the liquid has suspended solids, drying the liquid may leave grit, and solutions can leave a residue. There’s a small chance that the contamination is heavy enough to interfere with the laminar flow conditions needed for accurate measurements. In that case, the instrument can be flushed with isopropyl alcohol. Our service department can disassemble, clean and recalibrate for you. If you need service, you can request a return authorization, or call our customer service experts to make arrangements.

If you have one of our controllers with 316L stainless steel components—selected for their resistance to corrosion—you’re in the best possible situation. They are virtually identical, physically, to our liquid flow meters and have the highest degree of tolerance for liquids. [This might be a good time to ask: Did you know we make liquid flow meters and controllers?]

Customers—like the water treatment plant and air quality monitoring companies—have switched from ordinary thermal controllers to Alicat’s differential pressure controllers because they had run into problems. It’s one of the lesser-known benefits of our products, but if you are at risk, it’s a good reason to choose Alicat mass flow controllers and meters.

Have questions about this post?

You know one problem with anodizing and bluing? While it prevents corrosion, it can scratch off. Most anodizing doesn’t strengthen a surface much. Chrome plating has been an alternative, but chrome-6 is toxic, and can still wear, pit and spall. Duralar, a vacuum deposition system manufacturer, wanted to develop a fast, diamond-like coating process using physical vapor deposition that’s harder and more durable than either. It would have applications in prevention of corrosion, erosion and wear on metal parts.

Suppose, like Duralar, you’re a physical vapor deposition innovator. And just to make life interesting, let’s pretend that you don’t have unlimited time, and that money doesn’t grow on trees(!). R&D means testing, allowing for new formulations of barrier and reactive gases. You’ll need to change flow ratios and gases—all the while maintaining accurate flow, so success will be reproducible. You can’t keep buying new vacuum flow controllers for every test, and you can’t afford the downtime to have them recalibrated for each new recipe. You get the picture.

Duralar started with a generic vacuum deposition system, but none of the six built-in thermal controllers were calibrated for their special gas, tetramethylsilane (TMS), a vaporized liquid. The fact is, those controllers couldn’t change gases accurately, without downtime for a recalibration. So Duralar called Alicat. Although TMS isn’t on our standard list, with a bit of engineering we provided them with a corrosion resistant flow controller with a custom gas calibration for TMS.

After the diamond-hard PVD vacuum coating, plain steel shows as black.

They retrofitted their system using the Alicat controller—it’s a drop-in replacement—and they are now assured that the accuracy of their TMS flow will remain high, whether flowing full scale or turned down to 0.5% of full scale. That’s because Alicat’s gas selection isn’t just a k-factor offset for a single point, it’s a complete performance curve based on NIST’s viscosity tables. Going forward, Duralar needn’t worry about inaccuracy due to changing temperatures or pressures in their factory, since the closed-loop sensor in the controller compensates for volumetric changes—unlike those original thermal controllers.

Soon, Duralar was producing coated parts by pumping down the chamber to a vacuum, flowing in just the right amount of gases, adding material vapor and turning it to a plasma which bonds to the parts. In physical vapor deposition, the vacuum is needed because the chemistry won’t work in the presence of atmospheric gases.

A vacuum pump and three mass flow controllers for prototyping.

Next, they wanted to develop a process to deposit this thin coating inside tubes and pipes. With the inside of the pipe coated, you could reduce abrasive wear and corrosion—perfect for flowing abrasive liquids in a pipe, or protecting the inside of a rifle barrel from rust. The technique is clever: seal the ends of the tubes, and the interior of the tube becomes the vacuum chamber. The catch is, you need to be able to vary the location of the plasma-producing electrical discharge inside a narrow tube to get a complete coating. So, more prototyping, more experimentation, and Alicat to the rescue again.

By using an MCS flow controller for the corrosive TMS and just two more Alicat MC mass flow controllers, they were able to change gases at will, selecting from up to 98 built-in types and 20 user-customizable mixes—even more on the corrosion-resistant controller.

Alicat’s LabVIEW downloads customized to run a prototype system

Then, they used our downloadable LabVIEW drivers to build the vacuum process steps, controlling the MFCs and their shut-off solenoids from a remote laptop. In due time, they had perfected the process and begun building coating systems to order. Now, you can order diamond-like coatings for your metal parts—or the systems to provide the service for others—and the vacuum coating is more durable than anodizing, while quicker and harder than chrome plating. Thanks to Alicat’s flow controller adaptability, physical vapor deposition gets better and better.

Have questions?

Manufacturers of electrical power systems love Sulfur Hexafluoride (SF6): it’s a colorless, odorless gas which is chemically non-toxic to humans and animals, and has great usefulness in electrical insulation and arc prevention. Fill an electrical distribution switch box with SF6 and seal it, and you’ve increased the safety and longevity of the equipment.
Environmentally, though, SF6 has a drawback: while it doesn’t deplete ozone, it is the strongest greenhouse gas identified by the Intergovernmental Panel on Climate Change—by mass, it’s more than 22,000 times more potent in contributing to global warming than carbon dioxide! So, SF6 is tightly controlled around the world by environmental protection regulations.
As a power generation/distribution company using SF6, when you decommission a switch box, it’s critical to show regulators that you removed the same amount of SF6 as you put in years ago. That means accurate reclamation measurements—and it’s where totalizers, like the ones offered by Alicat on our meters and flow controllers, come in. A totalizer helps our electrical equipment manufacturing customers verify that they’re not venting this potent greenhouse contributor into the atmosphere… Using the totalizer, they keep the planet safe, and avoid a possible penalty.

With totalizing, a simple procedure sets up your batch dispensing.

How a totalizer works

A flow meter or controller reports a flow rate such as standard liters per minute (SLPM)—that is, the amount of standard volumes of mass passing through per unit of time. Supposing you have a 5 liter switching box, and you fill the box at 5 SLPM for 1 minute. You’ve now got 5 standard liters inside. A totalizer would tally up that flow, providing a running total, not just a reading of the rate. On a meter, you could periodically check the total on the front panel, or poll it electronically. On a mass flow controller, a totalizer becomes a precision dispensing instrument which saves you work and improves precision: you might set your totalizer to dispense 5 liters into the switch box, and start the totalizer. The controller then starts flow, counts down the liters until the 5 liters have been delivered (at your chosen setpoint rate) then it closes the control valve, and you’re ready to move on to the next step in your process. You don’t need to watch the flow rate on the display for spikes, and you don’t need a stopwatch.

Transformers, using SF6 for insulation, at a power substation.

Who else uses totalizers?

Gas totalizers are everywhere — the gas meter in your house has a totalizer (although it probably is only a volumetric total, calibrated to line pressure), and so does the gas pump for your car.
In industry, gas totalizers are used in:

• Beer brewing: for aeration of yeast mashes
• Gas blanketing: using nitrogen to fill the volume in tanks to avoid the emission of toxic or combustible fumes
• Pharmaceutical manufacturing: to dispense hydrogen in hydrogenation reactors
• Packaging: to fill each potato chip bag with non-reactive gas, keeping it plump without bursting.
• Custody transfer: whether filling a propane tank for commercial sale, or metering gas flows inter-departmentally at a research lab
• High altitude ballooning: by filling balloons with a precisely measured mass of buoyant gas, you can optimize altitude.
• Bio-reactors: regulating gases going in, or being siphoned off to control reactions.

Things to consider when choosing a totalizer

Does the totalizer allow batch processing?

This would be a programming option allowing a totalizing loop to be triggered from the memory of the device. Alicat totalizers offer batch loops. Another way to handle triggering is through remote software, such as our FlowVision application.

Is the valve tuned for your dispensing rates?

The tricky part about dispensing is getting the valve to shut just when you want to, in the way you want to. You may want a very quick valve snap at the end of the delivery, for the convenience of being able to move onto the next step quickly, but for high flow rates, it may be preferable to taper off flow as the total approaches, and then close at the most precise moment.
Either way, you will need tuning of the PID values to optimize the valve behavior. Alicat works to understand your particular situation so that the instrument is shipped from the factory with the right PID tuning. But we also provide the means for you to customize it in the field. Since our MFC’s all include 100 or more selectable gases, it’s not unusual for our customers to change the gases and processes the device is used with–we want you to be able to optimize your controller in each situation.

Which is better for your application: an integrated totalizer and valve (in an MFC), or a flow meter and remote valve wired together?

With a totalizer inside an MFC, the closed-loop relationship between the meter and the valve offers efficiency and precision. Plus, you don’t have to do the programming yourself! It reduces the number of devices you will need to connect to and maintain.
On the other hand, some customers have an existing valve, and just need to totalize flow, or they need the two elements to be physically separated for other reasons.

Do I need volumetric totals, standard mass totals or true mass dispensing?

Generally, each of these types of measurement would be handled by a different kind of flow measurement device. Our flow meters and controllers report volumetric as well as temperature, absolute pressure, and the standard mass flow. Any Alicat with a totalizer can totalize on volume or standard mass. By knowing the density of the gas flowing, we can program in true mass measurements. True mass is expressed in terms of mass per unit of time (e.g., kg/hr). If you’d like true mass data built into your Alicat meter or MFC, contact our applications engineers.

Whether you’re dispensing and reclaiming greenhouse gases, or if you need to calibrate a monitoring sampler (using a totalizer to provide average flow rate over time), or you need to measure grams per minute of oxygen going into a bioreactor for alternative fuel production, a totalizer from Alicat can enable and optimize your process.

Have questions about this article?

One way an Alicat meter or controller stands out from the rest is how much control you have over what it does, and how it does it. We pioneered user flexibility with our input screen. Now, you’ve gained an added level of control: user-selectable engineering units, among other things. With the new 6Vx firmware update, you’ll notice this and other improvements on new and updated instruments.

Change units without a factory visit

That’s right, you can switch units between several types! You’ll have full control of units of pressure, temperature, volume, standard volume or mass. The full list is on our Engineering Units page.

• Volumetric, standard or true mass flow: measure mass per unit of time (as in, g/hr) for any gas on the Gas Select table in your instrument, or standard volume per unit of time (sccm), or measure volumetric flow (cc/m)
• Change scale: (such as from sccm to Sm3/day)
• Change locality units: US to European, or vice versa (as from SCFM to SLPM)
• Match another STP standard: from “standard metric” (SLPM) to “normal metric” (LnPM)

More things to love

Generally, the interface screens are clearer and better organized.

• “Free range” STP: Enter any STP you want for your operating conditions, not just a couple of common standards
• More readable: Primary parameters in the center of the screen have a type label, beneath the number
• Faster data rates, by filtering your data line queries down to your essential parameters, you’ll get more frequent updates
• Input source: Controllers will take your setpoint input from either the local panel or through the serial port, without first switching the setpoint source. Both sources are active full time.
• Totalizer’s remainder: For controllers with the totalizer option, the display shows both the remaining amount in the batch as well as the amount dispensed
• Tare barometric changes: Portable meters with a barometric sensor (available only on new portables) will offer selections of barometric pressure, gauge stream pressure, and absolute stream pressure – and you’ll be able to tare to barometric pressure changes too. This can be critical in applications that are venting to (or drawing from) air, as local environmental conditions are then interactive with the system.

Can you get the update?

The new firmware is compatible with Alicat instruments of serial number 80,000 and higher, with a few rare exceptions (and configuration exceptions as noted above). You can have your firmware updated—at your request—at your instrument’s next annual recalibration. If you’re concerned that you may have one of the exceptions, our apps engineers can check for you.

The 6Vx firmware will be installed on new instruments shipped after March 3rd, 2016.

Have questions about this article?

Volumetric vs. standard volumetric vs. true mass

“Measuring flow rates” of gases and other fluids means different things, depending:

• volumetric rate: the space the material consumes, seen as “volume unit per unit of time” (e.g., liters per minute)
• molar mass flow rate: widely abbreviated to “mass flow” this is the number of molecules per volume under specific conditions, expressed as “standardized volume units per unit of time—under normalized conditions” (e.g., standard liters per minute, or liters normal per minute)
• true mass flow: measuring the mass of the molecules in the flow, which is reported as units of mass per unit of time (e.g., grams per minute).

Each of these types have their applications, but each is more technically challenging than the one before, because of added levels of complexity in the measurements. The most difficult one, resulting in the priciest solutions, is true mass flow.

So it’ll come as a significant advantage to our customers that Alicat now offers selectable engineering units on our instruments, including true mass, standard (molar) mass, and volumetric flow units—essentially extending our multivariate instruments into multi-purpose measurement and control devices.

Why doesn’t everyone offer true mass?

Measuring mass itself is always an indirect process. It means measuring momentum, weight or thermal capacity…there are several means. Some methods work with flowing fluids—for example, coriolis devices use a vibrating channel, and measure the variation on that vibrational momentum, which is caused by mass flow of gas or liquids through the channel. They are unaffected by changes in the fluid, or even chunky and dirty flows. The catch is, they’re expensive—several times the price of an Alicat instrument. And they will give you mass, but not any information about how many molecules are flowing, because they are ignorant about the media that’s flowing. (Find out more about measurement technologies in the “Types of Gas Mass Flow Meters” section of the How it Works page).

With updated firmware, an Alicat flow meter or controller can now measure true mass for your fluids—in units of your choosing—for any of the fluids on the unit’s Gas Select list, or any custom mix you build from those fluids. It’s true, you can order other mass flow metering instruments that have been programmed to provide true mass flow data for a single, known, pre-determined fluid. They’re programmed in the factory before shipment, but that fluid type can not be changed without a factory reprogram because the instrument is not capable of adjusting for changes in viscosity. The unit loses its traceable ties between its calibration and changed conditions.

With Alicat instruments, when you change gas types, you change the viscosity look-up of the gas itself — effectively re-calibrating the instrument to the new gas—all the necessary information is present to calculate true mass flow. For the same reason, we don’t have an accuracy modifier, which is common to other instruments, on our measurements when you change gases in our selection table. You can decide in the field to measure true mass, then change gas types (changing your selected gas setting, too), and stay as accurate as ever. You get true mass measurements, without paying the coriolis price.

Who needs true mass flow measurements?

In bioreactors like the one pictured at the top, systems engineers may be interested in measuring out-gas mass (for example, a fuel gas like methane) from the biomass. Metering this in kilograms can be more useful than liters. Conversely, regulating reactions in a chamber may be best measured in mass terms, for calculating consumption rates and predicting production output. Hypothetically, “I’ve got 4 kg of biomass, and it will require 2 kg of CO2 in the nutrient mix to keep it productive over the next 24 hours.”

In pharmaceuticals, gases and fluids are used in many reactions. A common process is hydrogenation, especially to provide coatings. Knowing the intended thickness, density, mass and area of coverage, one can calculate the required mass that would be added, and therefore using true mass dispensing of reactive gases into the process would be easier to calculate than converting standard volume into mass.

Measuring mass per unit of time is a powerful new capability, especially if you are dispensing or totalizing mass, as can happen with bioreactors or in pharmaceutical production.

The point is, it’s easy

While some users will benefit from true mass units, others will find an advantage in the volumetric, standard volume or pressure control capabilities that are already built into our instrument’s smart sensing. Nearly any flow system can benefit from the fact that the change between units is easy—a few clicks through the display menus, or a few instructions through the serial connection. This capability allows for easy repurposing of the flow instrument, or realigning units to correlate better with other calculations.

Have questions about this article?

Knowing the correct flow range for your application will help you select the best meter or controller for your system.

The flow or pressure device’s full scale should match the largest flow rate that you need to be able to measure. If your device has a higher or lower range than is required by your system, you will be unable to acquire a proper measurement.

In some applications the flow range is too wide for one device to handle. This is less frequently an issue with Alicat devices, thanks to a turndown ratio of 200:1. This is 4 times larger than industry standard devices at 50:1.

As an example, imagine you require a 50 SLPM (Standard Liter per Minute) mass flow meter to measure your highest flow rates. However, your application also requires you to measure a flow rate of 0.30 SLPM (300 SCCM) on the low end. This would mean that the device would need to measure a flow rate that is 150 times smaller than its full scale range. Below (or above) the specified flow range, your device may still detect flow, but since it is outside of specification, there is no scientific certainty to the numbers.

For the 50:1 turndown of typical devices, you’d have to buy two flow meters in this application. A 200:1 Alicat can handle both flow rates and remain within specification. The standard accuracy specification for an Alicat gas flow device is ± (0.8% of reading + 0.2% of full scale). A high accuracy calibration is also available. Both accuracy ranges offer 200:1 turn down capability, saving set-up time and money.

If you need an even higher turn-down ratio, such as 1000:1, two or three Alicat meters can be daisy-chained to fully cover the range of flows you are measuring.

Need to figure out your flow rate?

If you’d like some guidance on calculating a flow rate in your system, you can find pointers in the article “How to optimize flow systems“.

The post Flow range matters: it’s the speed limit appeared first on Alicat Scientific.

Compact, versatile and accurate BASIS mass flow controllers are ideal for original equipment manufacturing and process integration applications buying in volume. Now the product line includes ranges of 100 sccm, 1000 sccm and the new 20 SLPM model, each with digital communications options.

With the expanded range the new model provides, BASIS can now fit into more applications, such as sample dilution, sparging into liquids, and additional gas mixing systems.

The BASIS mass flow controller family was specifically designed to provide a fast, accurate, and economical package to OEM and process integration engineers. With its rapid control response speed of 100 ms, BASIS will react in real time to upstream fluctuations, producing a smoothly controlled flow downstream. Its accuracy is an impressive NIST-traceable, +/-(1.5% of the reading + 0.5% full scale).

The controllers offer a good flexibility of fluid type, with built-in calibrations for Air, Ar, CO2, N2, O2, N2O. He and H2 are available as single-gas units. This flexibility means integrators can use BASIS in a broad range of end-user products, selecting their gas type through any of multiple communications options—RS-485, RS-232, Modbus Serial and 0-5 Vdc analog. PLC and PC control are therefore also available, and the instrument provides either digital or analog feedback.

You can get specifications and learn more about BASIS MFCs on the product page, or by contacting your regional Alicat distributor.

Have a question about BASIS mass flow controllers?

Talking to your Alicat products digitally has just gotten easier. Whether you’re integrating an Alicat into a LabVIEW dashboard, or you’re using our Flow Vision software to log, control or optimize your flows and mixes, the new updates available on the download pages are compatible with our new Gas Select™ 6v0 firmware update.

Alicat Scientific has released updated LabVIEW instrument drivers for its mass flow meters, flow controllers, and pressure controllers. These drivers are backwards compatible for older Alicat instruments, and one version works for all Alicat instruments except BASIS—which takes a separate download.

In addition to the LabVIEW dashboard, which presents the full set of controls and reporting, the suite also offers dozens of simplified virtual interfaces—if you just want to do one thing through LabVIEW, you only need to include one of the simplified interfaces in your LabVIEW dashboard.The virtual interfaces are individualized panels for controlling a smaller set of features. For example, there are simplified interfaces for functions like taring, assigning a setpoint, and datalogging.

Available for free download at http://www.alicat.com/labview, the new device drivers enable users to more easily develop control interfaces to Alicat instruments or integrate Alicat devices into existing LabVIEW programs. LabVIEW provides data collection from Alicat instruments, instrument control capabilities, and integration with other process instruments. Common functions include evaluating data in order to trigger events such as changes to set points or flow rates, gas selection, validation, and monitoring ongoing process data.

Flow Vision software updated

If you have a new instrument, with the Gas Select version 6 software installed at the factory, or you recently sent an instrument in for calibration and the software was upgraded by the service department, and you have a license for Flow Vision, you’ll want to download the latest software update at the web site.

Since the Flow Vision software is backwards compatible, you’ll only need the one application for all instruments old and new.

Flow Vision is our proprietary software interface for communicating with Alicat Instruments. You can use it to adjust PID settings, change or poll registers, program scripts for various instruments in a system, or log and plot data.

There are two versions of Flow Vision: Flow Vision SC communicates directly with multiple Alicat devices, and provides direct control of them. Flow Vision MX configures up to six mass flow controllers within a gas mixing system.

Need more information about digital communications to Alicat products?

Use this form to contact our customer support Applications Engineers, or check out the software/drivers page for options.

Named a Halma plc ‘Company of the Year’ and recognized for international success

Tucson, Arizona (June 6, 2016) – Alicat Scientific has been recognized by its parent company, Halma plc, receiving “Sector Company of the Year,” and “Growth from International Expansion” awards. The Halma awards honor top performing companies from within its global group of safety, health and environmental technology companies.

This is the second year in a row that Alicat has been named Company of the Year in Halma’s Environmental and Analysis Sector. While one of the criteria is significant growth, the award also takes into account innovation, governance, and overall management. Alicat, which also won a Halma Innovation Award in 2015, has demonstrated a continuous investment in product and personnel development. Its mass flow meters, mass flow controllers and pressure controllers are used throughout the world in a broad range of industrial and research applications, from measuring methane emissions on farms, or controlling weld gases in production facilities, to providing data and pressure control in aeronautics research.

Alicat was also recognized for Growth from International Expansion, one of only two companies from among Halma’s 45 subsidiaries to receive this distinction. The award rewards growth in markets outside of the United States, United Kingdom, and Europe. Over the past year, Alicat has demonstrated outstanding growth in Asia and other markets outside the United States, particularly in India.

Based in the United Kingdom, Halma’s global subsidiaries develop and manufacture products for protecting life and improving quality of life for people worldwide. Its portfolio of market-leading companies are organized into four sectors: Process Safety, Environmental and Analysis, Infrastructure Safety and Medical.

Company Profile:
Part of the international Halma group, Alicat Scientific designs and manufactures mass flow devices used in medical and scientific instrumentation, as well as diverse industrial applications, for high-precision measurement of gas and liquid flows. Its all-digital product range includes mass and liquid flow meters and controllers; pressure gauges and controllers; portable flow meters; secondary calibration standards; software and accessories.

The post Alicat Scientific Wins Global Company Awards appeared first on Alicat Scientific.

Accuracy is the very first specification listed on a mass flow meter spec sheet because measuring flow is the whole point. But flow meter accuracy specs can be confusing, and that can lead to difficulty in evaluating the equivalence of options. Alicat’s standard accuracy specification is plus or minus 0.8% of reading plus 0.2% of full scale. Add them together, and they equal 1% at full scale. Other manufacturers list only a percent of full scale, or some other variation. If they list 1% of full scale, and Alicat’s equals 1% at full scale, then they’ll perform the same, right? Not so fast.

When Alicat Scientific checks accuracy of a mass flow meter, we check it against our certified in-house calibration standards, to be sure it’s within our accuracy specification. The testing compares readings at four flow rates: 100% (also known as ‘Full Scale’), 75%, 50% and 25% of the allowable flow of the meter. Here’s a two minute video on how we calibrate accuracy and what the specification means.

In a specification, percent of full scale (FS), means a percentage of the maximum rate of the device. Percent of reading means “a fraction of whatever rate is currently displayed”. Some manufacturers call this “variation from Set Point”, or S.P., but there isn’t really a set point on meters, just on controllers, which can be a little confusing if you’re reading a combined spec sheet. The main difference in your results is that percent of reading scales down as you decrease flow on a device, while percent of full scale is a fixed amount per instrument regardless of rate, which becomes comparatively more significant as you turn down flow.

While our accuracy specification is a combination of percent of full scale plus a percent of reading, some meters use only a percent of full scale parameter. How would other accuracy specifications affect your expected results? Consider these results from the 5 SLPM meter calibration in the video above:

Plotting these data points, the Device Under Test’s variation from actual, alongside the Alicat Specification and adding a “Brand B” 1% of full scale accuracy spec:

While both specifications start at the same uncertainty (plus or minus 1% at 100% flow), they diverge rapidly. At 25% flow, the Alicat specification comes to plus or minus 1.6% of the rate of flow…. Compare this to the ‘Brand B’ specification – at 25% flow, uncertainty is plus or minus 4% of the expected flow rate—an 8% uncertainty band. And that’s before calculating in the departure from accuracy caused by conditions that don’t match the standard temperature and pressure, or simply changing gases. On brand B that can be substantial. On an Alicat mass flow meter, the effect is small to non-existent.

Maintaining accuracy throughout a flow range is important, because how often is a meter used only at its maximum rate? With Alicat’s very high turndown ratio, it is an especially important question. If your system needs better accuracy than our standard accuracy, we offer a high accuracy calibration option, which is plus or minus 0.4% of reading plus 0.2% of full scale. And because we want you to have the very best results, we offer custom ranges for under-ranged applications, which maintain the instrument’s resolution for your specific flow system. For details check out the spec sheets, available on our mass flow meters and controllers pages.

Questions about Alicat Instruments?

The post Flow Meter Accuracy: Demystifying Spec Sheets appeared first on Alicat Scientific.

There are times when a high operating pressure is needed, and now you can use an Alicat for that high pressure system. It means you can take advantage of all the Alicat benefits you love so much: changing gas types on the fly, multivariate displays, and the controls and speed you depend on for a stable, repeatable process.

You can take a look at the new MQ meters and MCQ controllers for high pressure flow systems on the respective Alicat meter and controller pages. They handle pressures up to 320 PSIA (22 bar), a new upper limit on Alicat flow instrument performance. Minimum operating pressures are 15 PSIA for the meters and 30 PSIA for the controllers.

Like our standard instruments, the MQs and MCQs come equipped with our COMPOSER software, which lets you save up to 20 custom gas mixes (in 0.1% increments), composed from up to five of the 98 standard on-board gas calibrations. And the devices can be ordered in the same full scale ranges as the standard products, so it doesn’t matter if you are flowing less than 0.5 sccm or as high as 5000 SLPM. You can get a meter or controller for your application.

To ensure the highest possible measurement resolution and fastest possible control response times, MCQ high pressure controllers feature valves and sensors ranged to your application. Our standard control response time is less than 100 ms, and with custom tuning you can see performance under 50 ms (ask your application engineer for help with this). With Alicat’s industry-leading control response time, you can be assured that your process will be rock steady, regardless of the disturbances.

Full PDF specifications for high pressure flow controllers and high pressure flow meters can be easily downloaded.

Questions about high pressure applications?

The post Flow metering and control for high pressure flow systems appeared first on Alicat Scientific.

A pressure decay test can take a while, and waiting time is wasted time.

In this video, we demonstrate Alicat’s mass flow controller simultaneously controlling the pressure in the device under test, and monitoring leak rates as low as 2.5 sμlm. The result is an instant quantification of a leak rate, as soon as your system is settled at the target pressure. Nor do you need to do a lot of math to find an average leak rate—you’ll know the leak rate at any pressure you want tested.

Here are some ideas for optimizing this test:

• For testing larger volumes, a bypass fill-valve can be used to rapidly pressurize the DUT, reducing the wait between tests.
• An integrated bleed valve can be configured into the MFC for testing non-leaking parts… or you can include a bleed valve in your setup, as shown in the video.
• Using a low pressure drop Whisper controller will reduce stabilization times and ensures accuracy of real-time readings.

We have other configurations for measuring leaks, including those described in these papers from our Applications page:

• Faster Leak Checking
• High Efficiency Helium Leak Check

Leak check quickly using an MFC – without the delay of pressure decay tests

Questions about leak checking applications?

The post Even faster leak checking using pressure control loop on MFC appeared first on Alicat Scientific.

Design overcomes limits of high flow rates to maximize speed and accuracy

Tucson, Arizona (August 23, 2016) – Alicat Scientific has engineered a new mass flow controller with its highest top flow rate suitable to a wider range of applications. The MCRH can accommodate flow rates of up to 5000 slpm, without compromising speed or precision of gas control. The highly stable controller manages industrial processes with more chaotic upstream fluctuations, such as control of industrial combustion gases, or mass flow into food and packaging processes.
Alicat, 5000 slpm

New Mass Flow Controller engineered to overcome limits of high flow rates.

The MCRH 5000 slpm precisely and rapidly controls mass flow rate, volumetric flow rate, or back pressure of gases in high flow processes. To overcome the poor turndown ratio and slow response of existing methods (such as interlinking a meter with an external valve) Alicat designed a new flow geometry. This new design accommodates the higher flow rates, with a low pressure drop of 14.1 psig at full scale. A dual valve design enables a fast 100 millisecond control response time without significantly raising instrument power requirements.

The instrument’s Gas Select firmware includes a library of up to 130 preloaded gases, user selectable in the field. The MCRH 5000 slpm can be programmed with the instrument’s push button menus and on-board display, or via remote connection. Digital communications options include RS-232 or RS-485 serial, Modbus, or PROFIBUS, as well as analog 0-5 Vdc, 1-5 Vdc, and 0-10 Vdc, or 4-20 mA.

UK location to provide engineering support, product service and user training
Cambridge, United Kingdom (September 1, 2016) – Mass flow device manufacturer, Alicat Scientific, has established a new regional office in Cambridge, United Kingdom. The new location gives customers across Europe local sales and service for Alicat’s line of pressure controllers, mass flow controllers, meters, and accessories.

European Office will provide engineering support, product service and training.

The new office will be headed up by European Territory Manager, Andy Mangell. Mangell joined Alicat earlier this year, with a strong background in the European market and mass flow technology. Now that he has established a strong foundation in the region for application engineering support, calibration services, and end-user training, he is tasked with growing the localized support team and service capabilities.

“Alicat prides itself on the speed and accuracy of its instrument response time,” says Mangell. “However, within the discerning marketplaces where we operate, this is simply not enough. Providing the very best localized support is absolutely paramount to our devotion to speed. With this new location, we can ensure immediate engineering support, a quotation within hours, delivery within seven to nine days and service turnaround in under four days. This commitment to the European market is on-going, as we add yet more staff and capability at the Cambridge facility.”

Alicat is headquartered in Tucson, Arizona. In addition to the newly established Alicat Europe, the company has regional service and support centers in India and China.

Alicat Europe is located at 2 College Park, Coldhams Lane, Cambridge, CB1 3HD. Sales and support engineers may be reached by phone at 01223 472804 or via email at europe@alicat.com.

Alicat’s MCE-Series and MCV-Series direct replacements for common industry mass flow controllers
Tucson, Arizona (October 28, 2016) – Alicat Scientific’s mass flow controllers ensure the optimal coating environment in vacuum chambers, maintaining product integrity in coating and sputtering processes. The MCE-Series and MCV-Series may be used to replace legacy and discontinued MKS instruments. Made to fit the same space as common industry mass flow controllers, both series are easy to integrate into existing systems. In use, they offer fast, accurate flow control for process uniformity and quality.

Alicat’s MCE-Series and MCV-Series may be used as direct replacements for common industry mass flow controllers.

The Alicat MCE and MCV accurately control gas flow rates as low as 0-0.5 sccm full scale or as high as 0-20 slpm full scale with control response times of 50 to 100 milliseconds. Fast response times can greatly improve vacuum coating end products and help eliminate target poisoning. The integrated pneumatic shut-off valve is normally closed, affording positive shut-off of 1 x 10-9 atm-sccm/sec Helium max.

The MCE can be used as a replacement of the legacy Type MKS 1179A Mass-Flo®, while the MCV replaces the discontinued Type MKS 2179A Mass-Flo®. The Alicat mass flow controllers operate on universal 12-30 VDC supply, and Alicat will match any pre-existing pin out on 9-pin or 15-pin D-sub connectors, for easy replacement. The units can be mounted in any orientation, even upside-down, without recalibration, further simplifying installations.

Pre-programmed with calibrations for 98 gases, the MCE and MCV measure mass flow, volumetric flow, absolute pressure and temperature, with full temperature and pressure compensation. Units may be programmed directly through the instrument keypad or remotely via RS-232 (RS-485 also available).

The MCE and MCV use patented laminar flow differential pressure (DP) technology found in many Alicat Scientific flow instruments, are supplied with NIST traceable certification, and carry the CE mark.

* Type MKS 1179A Mass-Flo® and Type MKS 2179A Mass-Flo® are registered trademarks of MKS, Instruments, Inc. No affiliation, endorsement or sponsorship is stated or implied.

EPC family delivers responsive liquid or gas pressure control, tailored to application needs
Tucson, Arizona (December 7, 2016) – Alicat Scientific has added two new families of electronic pressure controllers specifically for high volume original equipment manufacture. The EPC family with single proportional valves, and EPCD family with dual valves, provide customized pressure control in embedded systems. The small footprint instruments respond quickly to upstream fluctuations to provide fast, accurate control of pressure in an economical, easy-to-integrate package. Alicat offers a choice of valves, valve orifices and process connections to fit customer specifications. EPC instruments are ideal for use in OEM gas chromatographs, fluidics dispensing for flow cytometry, and anywhere responsive pressure control is needed.

Alicat’s EPC family delivers responsive liquid or gas pressure control for high volume original equipment manufacture.

EPC and EPCD instruments have a 100 ms control response to still upstream pressure fluctuations in real time. NIST-traceable accuracy is 0.25% full-scale. The EPC family’s single proportional valve provides stable control of pressure in flowing applications, such as maintaining flow of carrier gas through the sample injection point in gas chromatographs. The EPCD features a second exhaust valve to provide efficient control of pressure in closed volumes, such as controlling the head space above a fluid for dispensing.

Alicat offers NPT, SAE, downport, and NeSSi process connections. Both digital (RS-232, RS-485, Modbus) and analog (0-5v, 0-10v, 4-20mA) communications are available to suit a range of end-user products. A choice in valve type and orifice allows for configuration to specific flow requirements for the best speed and stability.

Ethernet/IP and DeviceNet now available on mass flow controllers, meters and pressure controllers

Two new networking industrial protocols compatible with Alicat Instruments.

What’s cooler than having the world’s fastest lab-quality flow or pressure control device?

Did you think, “Networking that baby into an industrial process!”? Well, you read our minds, because so did we! … That’s so spooky!

Connecting flow and pressure controllers or meters to an industrial i/o system is easier than ever with the addition of Ethernet/IP or DeviceNet protocols. This brings the available list of protocols on Alicats to four:

• Modbus
• PROFIBUS
• Ethernet/IP
• DeviceNet

The new protocols are available on our mass flow controllers, series mass flow meters, and pressure controller products, as well as their versions in stainless, liquids, high pressure, high flow, dual valve, Whisper low pressure drop, and the like.

To get a protocol on your Alicat device, simply request the option when you order. The protocols are not available as retrofits. Visit our product options page to find additional information about the protocols available. Or ask our applications engineers. They love solving problems.

Have questions about using protocols?

Industrial automation protocols integrate mass flow and pressure instruments into process scheme

Tucson, Arizona (December 14, 2016) – Alicat Scientific has expanded its communications protocol offerings, adding EtherNet/IP and DeviceNet as options on its line of mass flow, pressure, and liquid instrumentation.

The new industrial automation protocols enable integration of Alicat instruments with PLCs running EtherNet/IP or DeviceNet. Real time data–including mass flow, volumetric flow, pressure, temperature, selected gas calibration, setpoint, and totalized flow of gases–can be read centrally by the PLC and used to manage Alicat controllers and meters. Users may change setpoint or gas selection, and issue other commands to Alicat instruments using a DeviceNet or EtherNet/IP enabled PLC or computer.

With response times as low as 100 ms, Alicat controllers rapidly and precisely monitor and control critical process parameters in chemical, medical, manufacturing and power industries. In addition to the new EtherNet/IP and DeviceNet protocols, Alicat offers Modbus-RTU and PROFIBUS communication options. Users may also select Alicat’s standard multi-drop RS-232 connectivity or the optional RS-485 for greater data integrity over longer distances. All Alicat instruments are backed by NIST-traceable calibration, comprehensive technical support and a lifetime warranty.

To learn more about Alicat’s flow, pressure and liquid instrumentation protocol options, visit www.alicat.com/ethernetip, or call +1 520 290-6060.

Accuracy, speed, size essential to operation of permeation devices

Tucson, Arizona (February 8, 2017) – Alicat Scientific’s BASIS mass flow controllers have been selected by Valco Instruments Co. Inc. (VICI) to precisely control gas flow rates in its Dynacal permeation devices. Alicat BASIS OEM instruments provide the control required by VICI to create gas mixes down to fractions of a nanogram per minute, in a compact footprint for easy integration.

Designed specifically for original equipment manufacture and process integration, BASIS is Alicat’s smallest footprint instrument. It controls gas flow rates used for mixing or diluting, or supplied into processes—such as gas analyzers, custom blending manifolds, and burners. Introduced in 2015, BASIS has been qualified and accepted by customers for gas chromatography, gas mixing, and sputtering for film coating, as well as burner applications.

VICI has incorporated multiple BASIS MFC’s into its Dynacal ® permeation devices, an integral component of its Metronics Dynacalibrators®, which are used to calibrate air pollution analyzers. The Dynacal generates the gas concentrations necessary for accurate calibration. BASIS handles the mass flow rates needed by the Dynacal to produce precisely measured mixes of trace quantities of gases with high precision, including two very low flow rates.

Several features of the BASIS product line have been instrumental in meeting VICI’s specifications. The BASIS is accurate at very low flow rates (e.g., 1 sccm), performing better than other mass flow controllers in its price class. Its high turndown ratio—as high as 200:1—means that fewer devices are needed to control a wide range of flow. Fewer instruments and a compact size ensure a space- and cost-saving fit, without sacrificing performance. BASIS also has a rapid control response time of 100ms, not attainable on most flow controllers of its size and ease of use. Its industrial interface facilitates rapid integration into gas flow systems.

The BASIS line of mass flow controllers come in three flow ranges: 1-100 sccm, 5-1000 sccm, and 0.1-20 slpm. They can be configured with six selectable gases—Air, Ar, CO2, N2, O2, and N2O—or with He or H2.

To learn more about the BASIS OEM mass flow controller from Alicat Scientific, visit http://www.alicat.com/basisoem, or call +1 520 290-6060.

Part of the international Halma group, Alicat Scientific designs and manufactures mass flow devices used in medical and scientific instrumentation, as well as diverse industrial applications, for high-precision measurement of gas and liquid flows. Its all-digital product range includes mass and liquid flow meters and controllers; pressure gauges and controllers; portable flow meters; secondary calibration standards; software and accessories.