Precision Scales Without Premium Cost

Many different kinds of industrial measurement devices are used to obtain information that is used during an industrial process. This may be an electronic thermometer to keep track of temperatures while mixing chemicals. Or a flowmeter to measure the amount of liquid that has been dispensed. Or a pressure transducer to keep track of pressure inside a tank or cylinder. Or calipers or micrometers to carefully measure distance. Almost without exception, there is a standard trade off in choosing the best device. Greater accuracy means a higher cost. Less expensive tools are less expensive. This has also been true with industrial scales. For the same class and size of device, the more accurate scales are more expensive.

Digital scales manufacturers have had a choice of two prevalent technologies. The most common has been industrial scales that use one or more strain gage type load cells. Smaller bench scales and parts counting scales use a single load cell mounted in the center of the scale platform. Larger platform scales and floor scales use one load cell under each corner of the scale platform. Depending on the size of the scale platform, intermediate sized scales, such as cylinder scales and drum scales may use either a single load cell or four. The accuracy of this type of scale is quite good, often delivering error levels of only one tenth of one percent. Using modern electronics, some of the other error terms, such as temperature effects and non linearity, have been improved with smart algorithms. But there is still a limit of accuracy that cannot be exceeded.

The second technology is known as force restoration. Industrial scales using this method can achieve accuracy levels up to twenty times better than strain gage electronic scales. Unfortunately, the cost is generally two or three times higher.

Arlyn Scales has invented a third technology for precision scales called Surface Acoustic Wave scales. Semiconductor transducers provide digital weight values that are equal to force restoration, but at costs that are similar to strain gage digital scales. These precision scales are also much more rugged than the other technologies.