Aggregates are everywhere we look in the world around us. These materials, which are made up of an aggregate of different other materials, including various types of stones, clay, silt, and sand, include the asphalt that paves our roads, the concrete that is used for the foundations of our skyscrapers, or the cement that makes up the bricks of our homes. There is no single aggregate-each one is made differently for a different purpose. One aggregate that uses a certain mixture of stones, silt, and petroleum-based binding may have very different characteristics than one that uses another mixture of pebbles, clay, and a different binding. One aggregate may be more suitable for roads while another may be more suitable for sidewalks.

On any construction site, construction managers must ensure that the aggregate they are using, whether concrete or asphalt, meets the specifications necessary for the job. Therefore, at set intervals of time, the team must carry out a compositional analysis of the aggregate. The aggregate is poured into a sieve with large holes that will only block the largest pieces of stone from falling through. Following this, it is poured into sieves with consecutively smaller and smaller holes until each component of the aggregate is in its own sieve. Then, the sieves and their contents must be weighed with an electronic scale. The total percentage of each material is calculated and compared with the necessary standards.

It is necessary to measure the composition of each aggregate very accurately. This becomes particularly difficult when each component may weigh up to 100 pounds. A standard digital scale may only be able to weigh each component to .01 pounds, which is not precise enough. One scale company, Arlyn Scales, has developed ultra-precision electronic scales that use Surface Acoustic Wave (SAW) technology for aggregate testing. These industrial scales are rugged enough to withstand the force of aggregate components while being able to weigh each component to .001 pounds.

Industrial scales are often subject to very harsh conditions. A cylinder scale may have to support a 250 pound tilted liquid gas cylinder as it is being loaded on and off. A platform scale may be subject to high shock loads as large pallets are placed on it by a forklift. Parts counting scales may also have to support these shock loads if a large batch of parts are placed on it at one time.

The most important component of any electronic scale is the transducer, which senses force, and outputs an electronic signal. Most often, the transducer is a strain gauge load cell. When force from an object acts on the load cell, it bends in a very controlled manner. When the object is removed, the load cell unbends back to its original position, much like a spring. A strain gauge, a type of electrical resistor, is placed on the load cell. As the load cell bends under the weight of an object, the resistance of the strain gauge changes. The weight of the object is proportional to the change in resistance of the strain gauge, which is affected by the amount of bending of the load cell.

Many industrial scale manufacturers choose to use aluminum alloy load cells in their scales since it is relatively cheap and it is very easy to machine. However, these aluminum load cells are very easy to damage. A shock load may bend the aluminum so much that it will not be able to spring back to its original position. If this happens, the electronic scale is no longer usable. Other manufacturers used nickel-plated steel load cells. However, these devices are susceptible to corrosion. High-quality industrial scale manufacturers, like Arlyn Scales, often choose to use a 17-4 stainless steel alloy. Load cells made from this material are very difficult to damage, and therefore, can sustain larger shock loads and can last longer.