Whether y
ou manufacture paint or sensitive chemical mixtures, you likely require a special level of precision from your scales at higher resolutions than other manufacturers. If you use liquefied gases as part of your industrial process, you’re also going to want an easy and reliable way to monitor amount of material in your drums.
Why Common Technologies Aren’t Good Enough
The average industrial scale, which uses strain gage load cells to determine weight, won’t meet these requirements. While this technology meets the needs of the vast majority of manufacturers, it does not have the precision or sensitivity characteristics that you need from your scales. And while magnetic force restoration (MFR) scales do provide the high resolution and precision you need, they can be expensive and have certain limitations and vulnerabilities. For example, they have a very low maximum capacity of about 50 lbs (often less). They’re also likely to experience drifts in accuracy due to changes in temperature, air currents, and vibrations – common conditions in a manufacturing environment. So where does that leave you? With the first major breakthrough in weighing technology in the last four decades: Arlyn Scales’ surface acoustic wave technology.
A New Technological Breakthrough
Load cells are the internal component responsible for determining weight. They generally use strain gages to detect the tension caused in the scale’s spring element when weight is applied to the platform. The strain gages are wired together to form a Wheatstone’s bridge and when the resistance of the gage changes, so does the voltage output of the bridge. This analog signal must be converted to a digital one before the weight can be displayed. This conversion and the spring characteristics of the element limit the accuracy and sensitivity of the measurements taken with this technology. Instead of reinventing the wheel, we took the same basic theory of load cell design and applied our ultra precision scale technology to it. Our Ultra Precision Scales feature use two surface acoustic wave (SAW) transducers that measure displacement of the spring element rather than strain. When an object is placed on the scale platform, it creates a bulk wave in the substrate of the spring element. This wave gets passed through the transmitting transducer and sent to the receiver where it gets amplified and sent back to the transmitter, creating a feedback loop between them. The frequency at which this wave oscillates between the two transducers depends on the distance between them. This distance is directly related to the bending of the spring element, which changes in accordance with the weight applied to the platform. This frequency is measured digitally and the signal is sent to the indicator where you see the numeric weight of the item.
Advanced Design Means Better Precision and Higher Resolution
We use semiconductor-grade crystalline substrates to fabricate our SAW transducers and deposit the electronics on these substrates using the same photolithography process used in the manufacture of advanced semiconductor devices. This advanced design creates a superior product that’s inherently more accurate than strain gage scales because it provides a fully digital output stream that results in precise, high resolution measurements. We also designed these scales specifically for tough industrial environments and eliminated the design vulnerabilities found in MFR scales. Sophisticated digital algorithms flawlessly compensate for changes in temperature, air currents, and vibrations caused by other machinery. So while they produce extremely sensitive measurements, they don’t have to be handled gently.
Seeing the Difference
Readability is a term scale manufacturers use to describe the performance characteristics of our products. It’s calculated by dividing the scale’s maximum capacity by its resolution. So, for example, a strain gage scale with a maximum capacity of 10 lb. and a resolution of 0.002 lb. would have a readability of 1 part in 5,000. This is the average readability of any strain gage scale. It simply means the scales can display 5,000 unique weights between 0.0 lb. and 10.0 lb. They also have an average accuracy of 1/10 of 1%, which means measurements will be ± 0.1% of the object’s true weight. Our Ultra Precision Scales have an impressive readability of 1 part in 100,000 and an accuracy of 1/100 of 1%! This means they have a readability that’s 20 times better a standard industrial scale and an accuracy level that’s 10 times better than strain gage load cells. Unlike MFR scales, our Ultra Precision Scales can have a large maximum capacity of 500 lbs. or higher. And while a strain gage scale at this capacity has a resolution of 0.1 lb., our SAW scales have an unrivaled precision of 0.005 lb. at the same 500 lb. capacity.
System Automation, Liquid Gas Monitors and Programmable Alerts
When combined with our optional set point controller, our Ultra Precision Scales allow you to automate certain manufacturing processes and monitor the level of material in your liquid gas cylinders. You can use any of the controller’s 8 target weights to signal the start up or shut down of other equipment such as feeders, mixers, motors, values, pumps, solenoids and other computerized devices. For example, a paint manufacturer can attach the set point controller to a vat of dye and use it to add the exact amount needed to a base of white. The set point controller can also be used to clear the pumps and pipes that feed liquid material into the larger mixing vat. By setting two target weights, you can use the first to slow the feed down to a trickle and use the second to shut the pump off completely. This means you’ll get exactly the amount of liquid you need without leaving anything in the system. And while some liquids can be monitored using a simple drum scale and the scale’s tare feature, this method doesn’t work for liquefied gases because the drum will appear full until the container is very nearly empty. This doesn’t leave operators a lot of time to refill or change the container. Our set point controller can also be used to create an alert system that lets workers know in advance when a container is running low on material so that there are no hiccups in the manufacturing process. If you’d like to learn more about Arlyn’s Ultra Precision scale technology and how it can benefit you, contact us today!
