One-stop Shop for All Your Atex Encoder Accessories
Our product portfolio has expanded now to include explosion proof accessories. These accessories are the perfect pairing for our explosion proof encoders which can operate safely in atmospheres where there are potentially dangerous levels of explosive gases or dust. Additionally, these accessories can be used with encoders rated Zone 1+21 and/or Zone 2+22 .
Rated Zone 1+21 and/or Zone 2+22
M20 & M12 Blind Plugs
M20 & M12 Cable Glands
Jaw Couplings for Solid Shaft Encoders
Draw Wires for Linear Measurement
Adapter flanges Available on Request
Application and Industries
POSITAL offers unique sensors to meet the needs of industries such as:
Andy is the sales director at Premier Control Technologies, a UK based process control technologies and products distributor which represents Alicat products.
Andy has over 30 years of experience with pressure and flow control instrumentation.
He can be reached at firstname.lastname@example.org.
My Grandad M. used to tell me: “In this life, my lad, you can’t get something for nothing!” He was, of course, referring to the benefits of hard work and his belief that if something is worth having then it is all the better for having worked hard to earn it. Having grown up with this ethos, and being a true Yorkshireman myself, I am not capable of seeing this as anything other than true.
Consider the following project:
We want to control four gasses at a high level of accuracy with a span from 0.1 millilitres per minute to 800 litres per minute. While controlling within that range, we also need to measure the pressure and temperature of each of the flowing gasses. Not a simple project, to be sure, but not outside the realm of possibility.
Let’s break down the instrumentation needed for this project. The average mass flow controller has a turn-down ratio of 50:1 of the full scale range. If our total measurement span is 0.1 millilitres per minute through to 800 litres per minute, we’re going to need a minimum of five MFCs. On the other hand, Alicat MC series mass flow controllers have a turn-down ratio of 200:1. With full scale of 20 milliltres per minute, 4 litres per minute and 800 litres per minute, a quick calculation shows that we’ll only need three Alicat instruments to perform the same task. Saving ourselves the need of two instruments is handy but it isn’t something for nothing yet.
Alicat’s Gas Select menu
The second piece of our project is the gases. Let’s say we need to flow four gases: nitrogen, carbon dioxide, argon and hydrogen. Most bypass MFCs are limited by precalibration per gas and require conversion factors between these gases. Unfortunately, our gas control project needs the ultimate in accuracy. The measurement uncertainty introduced by the k-factors is just too great. Argon alone can have a conversion factor error of as much as 2.8% above standard calibration uncertainty. So now we need separate instruments for each gas to get reliable data. Four gases times five instruments and our cart is getting full. Even if just flowing one instrument at a time, a total of twenty instruments would be required to cover the whole spectrum.
Alicat MFCs are preset with over 98 gases and gas mixtures – all certified within the standard calibration accuracy. So for the same process as above, flowing just one instrument at a time, would still only require three instruments needed to cover the whole spectrum. Assuming a cost of £1000 per MFC, we can see that if we used average instruments, our costs would be at least £20,000. And with Alicat devices? A much more palatable £3000.
But controlling the flow is not all we need our MFCs to do. We also need to measure both pressure and temperature per gas. A pressure transducer, a temperature transmitter, the fittings required, the cables and installation costs could amount to at least £400, probably more. Times four.
Not so with an Alicat. Their mass flow controller includes pressure and temperature measurement so there is no additional cost whatsoever. Plus, with the push of a couple of buttons, it can be reset to perform the opposite action and control the pressure whilst measuring the flow.
With our average MFCs we have to have a system to control the two dozen devices we’d need for this project. An Alicat device, on the other hand, is easy to integrate into a preexisting setup with analog or serial communication protocols, but if we didn’t have a system in place, we can control our three Alicats right from the front screen of the devices.
Pulling all of the above together we can see that for our gas control project, using the average MFCs will need at the very minimum an investment of £20,000 for the instruments themselves, £1,600 for pressure and temperature measurement and £2,000 for a readout and control module. A total of £23,600. By using Alicat instruments an investment of £3,000 would achieve the same results.
All Alicat instruments come with the industry’s only lifetime warranty.
It’s simple maths. Even Grandad M. would agree that Alicat instruments have so many additional features and capabilities you get, if not something for nothing, so much more for so much less.
Measuring Wheels: A Great Solution for Equipment Positioning Tasks
POSITAL has introduced a series of measuring wheel accessories for its IXARC family of rotary encoders. When one of these wheels is mounted on the shaft of an encoder, the result is an accurate and reliable instrument for measuring linear motion and position.
With the new measuring wheels, POSITAL provides a very convenient way to make linear displacement measurements while taking advantage of the proven performance of our extensive line of rotary encoders.
A Linear Measurement Range of up to 500 Kilometers!
The new measuring wheels are available in circumferences of 200 mm and 500 mm. When fitted to multiturn IXARC absolute encoders, this would translate into a linear measurement range of up to 500 kilometers!
Three rim treatments are available to ensure good traction between the wheel and a variety of surfaces.:
Textured (knobby) Polyurethane
What is a Measuring Wheel? Watch and Learn!
Combination of Measuring Wheels and Programmable Incremental Encoders
POSITAL also offers great benefits from the combination of measuring wheels with our programmable incremental encoders. With this arrangement, a user could define exactly how many pulses the instrument would produce for a defined unit of linear motion. IXARC programmable encoders can be easily calibrated at the job site using POSITAL’s convenient UBIFAST programming tool.
Trigas FI, our Alicat distributor based in Münich, Germany, is now Alicat’s first authorized Calibration Center. Trigas calibrates all manner of gas and liquid flow instruments and has a well-equipped lab with one of the best calibration standards in Europe. With lead times as short as 48 hours, Alicat customers in Europe may save time and cost versus shipping the units to America.
DAkkS accredited to ISO 17025 for all their calibrations
20 years of experience in calibration business
certified in best practices for Alicat instruments
Trigas distributes Alicat instruments for automation and process control applications in Germany, Austria, Switzerland, Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Macedonia, Montenegro, Romania, Serbia and Slovenia. Contact tfinfo@TrigasFI.com for more information or see their representative listing for further contact information.
Alicat mass flow meters and pressure controllers are precisely engineered and rigorously tested. These devices are designed to maintain high accuracy calibrations while mitigating the effects of environmental factors. Because we believe it is important that our devices maintain performance after purchase, we have a team of Application Engineers to help customers get the most out of their instruments. In the event an Alicat device isn’t working as expected, we’re here to help identify and resolve the issue as quickly as possible.
If it ain’t broke… troubleshoot!
Many problems can be fixed without having to return the device to the factory. We’ve outlined some common issues and their solutions below:
Alicat’s Gas Select™ menu
Incorrect Gas Selected
Alicat devices can flow over 98 gases and gas mixes, but it is important to verify that the gas selected on the device matches the gas used with the device. Flowing a different gas than selected usually won’t have any negative effect on the device itself. However, the measured flow readings will be off by approximately the ratio of the viscosities of the two gases. The data can be brought to near correct readings by multiplying each reading by the ratio of the selected gas’s viscosity to the desired gas’s viscosity.
To prevent the problem from occurring again, update the gas selection in the Gas Select™ menu as soon as possible.
Negative Flow Readings
A negative reading when there is no flow usually means the meter was flowing when it was last tared. To fix the problem, make sure there is no flow and give the instrument a fresh tare by selecting MENU > TARE from the home screen to correct the problem.
When an Alicat unit leaves the factory, the valve is configured to operate at certain standard conditions. Sometimes these valve characterization conditions do not match the actual operating conditions. When this happens, it is possible the device won’t control with the speed or stability typical to an Alicat controller. Don’t panic! With Alicat devices, it is possible to change gains in the control algorithm from the front panel and via serial communication. More often than not what seems to be a non-functional unit is just a controller configured for a different specific application.
Find complete FAQs and troubleshooting documents in the Alicat Knowledge Base.
Having trouble troubleshooting?
We have a growing knowledge base online to make operating the instrument easier. However, some problems require more in depth knowledge on how the Alicat is (or isn’t) working. If that is the case, Applications Engineers are available to help by chat (in the bottom right corner of the page) or by phone +1.888.290.6060.
Get assistance from an Application Engineer to get the most out of your Alicat device.
When it is broke… We’ll fix it.
Sometimes troubleshooting can’t fix the problem. For a variety of reasons, Alicat devices must be returned to the factory for repairs. To speed up a repair, include as much information about the failure or error and any troubleshooting that has already been performed so our team can focus on finding and resolving the issue.
The most frequently seen failures, how to spot them and how to avoid them in the first place are outlined below:
The most common service issue we see is contamination in the flow path. Without the proper precautions, foreign particles and debris collect in the valve and flow body and can cause the unit to clog or read erroneous flow rates.
Contamination can be as severe as a spiderweb inside the device.
To help prevent this, always clean fittings before installation and make sure to flow the appropriate gases from clean sources. We also recommend that appropriately-sized filters be installed throughout the process to protect against contamination.
Running the device at pressures beyond its specifications may damage the sensors. If the Alicat is reading strange values when no pressure is applied, it is possible that the sensor has been over-pressurized and is no longer functional.
To avoid damaging the sensor, always remember to use your Alicat device within the stated operating conditions. Refer to the device’s manual for these conditions. Exceeding them puts the Alicat device at risk of catastrophic failure
Electrical Issues or a Blown Transient Voltage Suppressor (TVS)
Failure to follow the correct power and communication specifications can result in catastrophic failure to the electronics in your device. Alicat devices contain TVSs to help protect the unit from power issues. Signs of blown TVS include anomalous voltage input/output readings to total loss of communication. If the device expresses one of these symptoms or seems to be pulling excessive current do not continue to operate the device.
To prevent electrical issues be mindful of what power source is being used to operate an Alicat device and take extra care to ensure wiring from the power source match the correct specifications.
Drifting Sensor Readings
All Alicat device readings will drift a little, well within specified accuracy. Drift is due to limitations of the sensor and is not cause for concern. To ensure accuracy of readings, always tare the Alicat device before use when the sensor is depressurized (and not in flow conditions).
If the device seems to be drifting more than the allowable specification, take note of flow and pressure readings at power up of the device and log these readings every five minutes for an hour. Deviation greater than 0.2% of the full scale range may mean that the sensor is defective.
Fill out a service request for repairs and recalibrations of your device.
To ensure that every device maintains specified performance and within warranty, we recommend annual recalibration of every Alicat device. By recalibrating annually, slight changes in flow readings that are within specification but are showing signs of drift can be corrected. It is also an opportunity to reconfigure the device to a new experiment or process, upgrade features and catch potential issues before they become problems.
POSITAL has extended its portfolio of rotary encoders with a new family of through hollow incremental encoders. These devices are designed to be installed with the machine shaft passing through the sensor. They can be used to monitor rotary motion in a wide variety of machinery, including servomotors, material handling equipment and printing presses, offering cost-effective, space-saving solutions. They can be easily installed between the body of the motor and other components mounted on the shaft.
Easy to Install, No Shaft Alignment Required
Compact, Adjustable, and Versatile Design
Variety of Shaft Bore Sizes from 10mm to 42mm, Including Imperial Sizes
Install Directly on Shaft, No Need for Extra Coupling
Wide Variety of Applications
Large Variety of Configurations
POSITAL’s through hollow encoders are available for shaft diameters ranging from 3/8 inch (9.5 mm) to 1-3/4 inch (44.5 mm). The smaller units (up to 14 mm shaft opening) have an external diameter of 2-1/4 inch (58 mm), while the larger units (5/8 inch to 1-3/4 inch shaft size) have external diameters of 3 or 4 inches (77 or 100 mm). Available resolutions for these devices extend from 360 PPR to 4096 PPR (pulses per revolution).
All through-hollow encoders have rugged aluminum housings and environmental protection rated at IP65, ensuring longevity and high levels of operational safety. All variants are available with a variety of communications interfaces , including RS422 (TTL) 5V or 11-30V and Push-Pull (HTL, 5-30V). Connection options include built-in cables or MIL-type connectors.
Recently we worked with a customer that needed to control the pressure in a reaction chamber between -200 to +200 cmH2O. However, though the customer’s building had an ample supply of compressed air, they had no vacuum source. Without suction, they were unable to reach negative gauge pressures. We went to work finding a solution that not only met the customer’s needs but could be added directly to the product they were purchasing. By installing a Venturi vacuum generator on an Alicat Dual Valve Pressure Controller (PCD), the customer was able to use their compressed air source on the system to create the necessary suction for controlling to sub-atmospheric test pressures.
Use an Alicat PCD to maintain pressure in a system with almost no waste from off-gassing.
Alicat PCD-Series dual-valve pressure controller
What is the Venturi effect?
When fluid flow moves from a less restrictive to a more restrictive environment, its velocity must increase – such as spraying water from a garden hose by placing your thumb over the open end. According to Bernoulli’s Principle, this increase in velocity is associated with a drop in pressure. Thus, fluid flow passing through a restriction will have a resultant pressure drop – this is the Venturi effect.
How to use the Venturi effect to create a vacuum
For our customer above, we added a third party Venturi vacuum generator on the exhaust valve of a Dual Valve Pressure Controller. This turned out to be a size-conscious and cost-effective way to create a vacuum without adding a vacuum pump into the system.
It works like this: The Dual Valve Pressure Controller is designed to allow flow to easily escape through the second valve as needed to maintain constant or near constant pressure in the system. In this case, the Venturi vacuum generator accepts a compressed air inlet and flows this through a restriction to create an induced vacuum of about one PSIA, which is plumbed to the exhaust valve of the Dual Valve Pressure Controller, utilizing the compressed air flow to create a vacuum.
Connect with an expert Applications Engineer to find your ideal solution.
The Alicat team works tirelessly to not only engineer and produce the fastest flow and pressure controllers in the world but to find solutions to problems for specific experiments or process set ups and do what makes the most sense for every customer.
POSITAL’s Wiegand assemblies offer a compact and efficient way of harvesting power for electronic circuits in electromechanical devices, eliminating the need for backup batteries.
The operating principle of POSITAL’s Wiegand modules is simple. A “Wiegand wire” is a short length of specially prepared Vicalloy (vanadium-iron-cobalt) wire. When exposed to a changing external magnetic field (e.g. a nearby permanent magnet mounted on a rotating shaft) the Wiegand wire will initially retain its original magnetic polarity, and then abruptly ‘flip’ its polarity when the change to the external magnetic field reaches a certain threshold. This sudden change in the magnetic state of the core induces a current pulse in a copper coil wound around the Vicalloy core. This current pulse is very short-lived, but the energy harvested from the mechanical movement of the magnet can be captured and used to activate a low-power electronic circuit. An important feature of the Wiegand effect is that the amount of electric power generated with each reversal of the magnetic polarization is constant and completely independent of the rate of change of the external magnetic field, even if this happens very slowly. POSITAL Wiegand modules have been used to reliably power rotation counters in tens of millions of devices, including multi-turn rotary encoders, gas and water meters.
Production Since 1974 – Started by John R. Wiegand
Proven In Encoders & Water Meters Since > 10 Years
Used In Access Cards For > 30 Years
Power Supply For Future IoT Applications
High Energy Output of ~170 nJ
“The process for making Wiegand wire from raw Vicalloy wire was invented by John Wiegand in the 1970’s” comments Christian Fell, Chief of Technology Development for POSITAL-FRABA. “It involves a complex set of steps, including cold-working the wire through a combination of stretching and twisting, then heat-treating the product to lock in the desired characteristics.” POSITAL acquired the original wire-conditioning machinery and intellectual property from the Wiegand estate in 2013. Fell continues: “This acquisition has meant that we have reliable supply of Wiegand wire. It also gave us an opportunity to refine the manufacturing process for improved product quality. Thanks to our research, we can now produce wires that reliably generate 190 nanojoules of energy at 7 volts with each polarity flip”.
Wiegand assemblies are a core component in POSITAL’s IXARC multiturn absolute rotary encoders, providing a maintenance-free method for powering the counter that records the number of complete rotations that the device experiences. POSITAL also offers Wigand assemblies to other manufacturers. These consist of a 15mm length of Wiegand wire surrounded by a copper coil, all contained in an SMD-mountable plastic structure. Wiegand wire production is carried out at locations in the U.S. and Europe, ensuring a stable, reliable supply chain. These assemblies can be used wherever low-cost, zero-maintenance, battery-free energy harvesting systems are needed to energize electronic counters and other low-power electronic devices.
See just how fast the fastest mass flow meters are, in person, at Pittcon 2018®. We can’t wait to share our mass flow and pressure controllers with visitors, scientists and customers. Stop by Booth 1830 to see demos of Alicat products and chat with our flow and pressure experts about your applications and how to make them more accurate and efficient.
Pittcon, or the Pittsburg Conference on Analytical Chemistry and Applied Spectroscopy, is an annual conference for analytical and laboratory scientists. As science and technology progress, Pittcon is where scientists, researchers and manufacturers can stay up to date with discoveries and advances in instrumentation. Alicat instruments are used in analytical and laboratory instruments, including aroma mixers, chromatographs and spectrographs—and for calibrating them as well.
The Expo will run for three days, Tuesday, February 27 through Thursday, March 1, from 9 am to 5 pm daily at the Orange County Convention Center – West in Orlando, Florida. And it wouldn’t be Florida without the opportunity to meet and greet with an American Alligator between product demos.
If you are attending Pittcon 2018, stop by and say hello to us and check out our newest and coolest products. Or get in touch with one of our Application Engineers online or on the phone at +1.888.290.6060 to learn how the fastest mass flow controllers in the world can make experiments, regulatory instrumentation and other fluid and gas control applications faster and more accurate while saving time and operational expense.
When exact measurements and highly accurate data is critical to the success of an experiment, test, calibration or other application, maintaining a precisely calibrated device is key. To meet the demands put on them, we recommend that all Alicat meters and controllers are recalibrated annually.
When a device is sent in for recalibration it is an opportunity not only to maintain the quality and precision of the device, but also an opportunity to update firmware or, if your application needs have changed, the perfect time to work with our Application Engineers to find a solution that allows your Alicat to be adjusted or upgraded to meet your evolving needs without the hassle and expense of buying a whole new instrument.
Over time, minor physical changes to the laminar flow elements and pressure sensors inside the device, such as particulate deposits or damaged flow elements, can alter the flow characteristics of the device’s flow path. These altered flow characteristics can affect the pressures transmitted to the absolute and differential pressure sensors in the device’s flow body, causing the calibrated flow curve to inaccurately represent the actual flow rate. With an annual recalibration, out-of-calibration instruments are brought back to their optimal and exact calibration specifications and, if need be, can be cleaned.
Even if the device arrives at our factory or a service center within its prescribed flow tolerance, our service technicians recalibrate the device to be truer to the actual flow rates read by the calibration standard at the necessary calibration points. Alicat can also provide additional or replacement calibration points, if something other than the standard five calibration points is required. Additional calibration points or upgrade of accuracy to ‘high accuracy’ specification can be requested for instruments.
A calibration procedure is demonstrated in this video about accuracy:
Standard calibration typically takes fifteen business days to complete once the device arrives at one of our facilities. With such a quick turnaround time, you can be back to fully operational with a highly calibrated instrument with minimum interruption. For around the clock use of an Alicat, our Application Engineers will work with you to find a suitable and cost effective solution and the right back up device to keep the process running and the instruments in peak calibration.
If ISO-17025 calibration is required by your organization, Alicat can provide this kind of calibration through trusted third party calibration services. ISO-17025 calibration can add about 10 business days to the standard calibration lead time.
Sending your instrument back for recalibration every year keeps the lifetime warranty of your Alicat in place.
Where can Alicat instruments be calibrated?
We recommend that all devices come back to one of Alicat’s approved facilities for recalibration. Most devices will be recalibrated in our Tucson, Arizona headquarters and factory. However, if you are not located in North or South America, there may be a closer location you can send instruments for faster shipping. Alicat currently has service centers in China and India and has a factory authorized service center in Europe.
Getting recalibration started
More information about the costs and benefits of recalibration can be found on the Alicat website or by contacting one of our expert Applications Engineers. To send your instrument in for calibration to Alicat, fill out the service request form. The form lets us assign a Return of Materials Authorization (RMA) number, which is needed for us to receive and process your instruments at the factory. After sending in the form, we can send you instructions for packing and shipping your instruments.