Metrology equipment like industrial scales are essential for a wide range of commercial operations. Higher resolution is particularly important for any operation in which you must be able to detect the most minute changes in weight.
For many years, high load cell resolution was something that could only be found on a laboratory scale. Resolution in scales beyond 50 lbs. was average, at best; and the higher the capacity, the lower the resolution.
Higher capacity scales just could not produce the necessary accuracy and resolution that some operators required. However, here at Arlyn Scales, we’ve been working day in and day out to help solve this problem, and we are pleased to announce that we have found a solution: Surface Acoustic Waves.
What is the Best High Precision Load Cell?
Higher load cell resolution and accuracy is now available for high-capacity scales with this incredible innovation. However, before we talk about our load cell solution for higher accuracy and resolution, it’s important to talk about the kind of standard technology that exists for scale purchasers and users.
There are several forms of load cells, including:
- Strain Gauge Scales
- Magnetic Force Resolution (MFR) Scales
- Surface Acoustic Wave (SAW) Scales
The primary difference between them is in how they determine weight measurements, but this difference often impacts their effectiveness.
Strain Gauge Scales
Strain Gauge instruments have been the standard of the scale industry for more than sixty years. Any load that is placed on the scale platform is transferred to the load cell, so the foundation of these scales is their strain gauge load cell.
How Do Strain Gauge Load Cells Work?
The strain gauge load cell is precisely machined using computer-controlled machining centers. The load cell uses four, thin sections called flexures that are machined out of a thin metal, usually aluminum.
The strain gauges are bonded onto the flexures, so they bend when the flexures bend. Once a force is applied, they bend, and the gauge’s resistance changes.
The gauges are wired together in the form of a Wheatstone bridge.
The bridge’s voltage output changes when the resistance of the gauges changes. The voltage is then translated into a numeric format by the Analog to Digital Converter, which corresponds to the object’s weight.
However, the thin metal design of this load cell can create significant vulnerabilities in the scale.
A drift in accuracy can be caused by damage to the load cell, including:
- Shock Loading: Dropping a load onto the platform
- Overloading: Placing a load on the platform that’s beyond the scale’s capacity
Once the load cell is damaged, the scale must be taken out of service for repairs. This downtime may impact your productivity and your budget.
Our strain gauge load cells are manufactured from stainless steel, which makes them more durable and more accurate. However, they don’t provide the high resolution required by some applications.
Magnetic Force Resolution (MFR) Scales
The MFR scale is a great alternative for a high resolution and precision scale, but only for low capacities. Using electromagnetic force to measure the weight on the platform, the scale has high accuracy and resolution.
However, these scales are vulnerable to air currents and temperature changes in the work environment. This can create drifts in accuracy. Additionally, from a practical perspective, they can only provide scale capacities up to about 25 lbs.
Finally, the scales aren’t economical enough to be beneficial. These scales, while sufficient enough for some applications, cannot provide higher resolution at higher capacities. They are primarily designed for laboratory work or working with small amounts of materials.
Surface Acoustic Wave (SAW) Scales
SAW load cells measure displacement, as opposed to the stress and strain that the strain gauge load cells measure. Inherently better than strain gauge load cells, the spring element of our SAW load cells have one transmitting transducer and one receiving transducer placed on either side.
The receiver detects the SAW wave coming from the transmitter, and after it’s passed between the transmitter and receiver, it’s amplified and fed back to the transmitter. When weight is placed on the load cell, the spring element bends, which changes the frequency at which the SAW wave is passed between the two transducers.
By measuring this frequency, SAW load cells can digitally determine the weight of an object. This means that precision is inherent, since there is no analog-to-digital conversion taking place.
What is the Load Cell Resolution & Load Capacity of SAW Technology?
SAW scales are capable of weight capacities of up to 500 pounds, and for lower capacities, with resolution as fine as .0001 pounds — that’s 1/10,000th of a 1 pound!
This makes them up to twenty times more accurate than their strain gage counterparts.
What are the Benefits of Choosing High Resolution Scales from Arlyn Scales?
Arlyn Scales is a leader in the scale industry and has been for the past thirty years. We work hard to make sure our scales are both tough and contain cutting edge technology.
Our research and development staff constantly works at finding new ways to push the envelope — for current industries that use scales and emerging applications that may someday use them. We stay informed of new advances in metal alloys, electronics, and scale components (like our high quality load cells).
Our internationally patented Ultra Precision Scales, for example, utilize SAW technology.
They’re much more budget-friendly than MFR scales.
We manufacture our scales in our factory located in Long Island, New York. It’s conveniently located at our company headquarters so we are able to ship factory direct to our customers.
This helps them save money that distributors would normally add on to the price.
We take the money we save from shipping the factory direct and use it to deliver a high quality scale that our competition can’t beat even at normal retail prices.
Find the Best High Resolution Load Cells at Arlyn Scales
Whatever precision scale you decide to purchase from us, rest assured that our customer support staff is highly trained and very knowledgeable about our product line. Not only do they know about our scales, but they also have years of experience in the scale industry and can provide practical, applicable tips.
Should you find that the standard models of our precision scales do not quite meet your company’s expectations, we are more than happy to discuss the various customization options. To learn more about our Ultra Precision scales and SAW load cells, reach out to our team today.