Weighing instruments have many applications in many industries, so much so that it is easy to ignore how important they are in many of these applications. For centuries, the simple weighing scale has long been part of commerce. From the most precise laboratory instrument to the heavy-duty industrial type scales used in mining and construction, these scales are integral to specific processes such as quality control.
How do balances and scales work?
A balance works by matching the object to be weighed against a reference weight. Balances are commonly used in precision applications such as laboratories. Nowadays, most conventional balances have been replaced by an electronic weighing scale which is easier to use and more reliable.
A weighing scale, on the other hand, typically has springs and other mechanical components. Therefore, a digital scale and a mechanical scale function almost the same except for how the readouts are displayed. In a digital scale, a digital converter translates analogue data similar to how an MP3 player converts music waves into digital format.
In general, a digital scale is easier to use even if you are not an expert. These devices are also highly precise and process information faster. Nevertheless, the capacity of each weighing instrument varies, especially when it comes to weighing large objects.
The load cell
Although weighing scales come in all shapes, sizes, and designs, a common component shared by these devices is a load cell. It is similar to a transducer which functions by converting energy into a different form. In a digital weighing instrument, the load cell converts mechanical energy into an electrical output. Another widely used type of weighing component, the strain gauge, reads minute changes in electronic resistance. In both a load cell and a strain gauge, another principle remains the same. The readout produced will be transmitted to a CPU and interpreted using a display board.
Different weighing scale designs
Although a strain gauge is the most common type of load cell used today, there are many industries that require a different load cell design for their weighing instruments. For example, in a working environment where it is necessary to maintain a higher level of safety, it is often better to use a pneumatic load cell. Applications include food processing industries and other hazardous worksites because a pneumatic load cell does not contain any fluid and requires a clean and dry environment to function.
In contrast, a hydraulic load cell is commonly used in mobile weighing applications where there is no access to electricity. These devices are more rugged and can weigh heavy objects like trucks.
In addition to the type of load cell used, the specifications of a weighing scale also vary. From accuracy and measurement repeatability, range, and precision, there is an instrument that can meet almost every application requirement and budget. Manufacturers can also custom-design a scale should the client require it.
And while weighing scales may seem like ordinary pieces of equipment used today, their importance in various industries cannot be denied.
