Before we answer the question of why we use load cells to measure weight, let’s take a step back and examine the basics of weighing.
Interestingly, weight is actually the amount of force that the acceleration of gravity exerts on an object and because it’s a force, the proper scientific unit of measurement is a Newton, written as N. However, the conventional definition of weight is actually mass, which is the amount of matter something contains.
The need for units of weight and measurement has evolved since the earliest civilizations and it’s impossible to imagine everyday life without being able to weigh things. From bathroom and kitchen scales to bags of tomatoes in the supermarket and suitcases on an airport conveyor, we rely heavily on the ability to measure items by weight.
And that’s from a personal perspective. The ability to measure weight is also a critical business imperative across the A-Z of industry from agriculture to zoo-keeping. Whether it’s determining the weight of the raw materials or the finished products, any operation involved in the production, distribution or servicing of a physical object has a need for accurate weight measurements.
Early load cells
Load cells were developed in response to a growing need for more accurate and more reliable methods of weighing and the first bonded resistance wire strain gage was introduced in 1938. However, the new technology only became technically and economically feasible with the development of modern electronics – and since then various types of load cell designs have proliferated throughout industry.
How load cells work
Essentially, load cells convert force into a measurable electrical output and the various types include hydraulic load cells, pneumatic load cells and strain gauge load cells which are the most common in industry.
Strain-gage load cells convert the load acting on them into electrical signals and in the majority of instances, four strain gauges are used for maximum sensitivity and accuracy. The gauges themselves are bonded onto a beam or structural member that deforms when weight is applied, but they need to be sufficiently robust to withstand the continuous shock, vibration and heavy loads in their often harsh operating environments.
A more recent development has been the introduction of digital load cells. These measure capacitance as opposed to the strain in the load cell body, and they have the same advantages as analogue load cells but with improved functionality. They can be interfaced with other equipment more easily, they’re harder-wearing and more resistant to outside forces such as shock, wet conditions and corrosion – plus the speed and efficiency of digital communications makes it possible for faster and more efficient information transfer.
From a productivity and profitability perspective, anything that speeds up operations, improves accuracy, reduces costs, increases throughput and output and makes things more efficient, user-friendly and manageable, translates into bottom-line benefits. And those are all key reasons why operations use load cells to measure weight.
Different types of load cells
Load cells are necessary for many different load-bearing applications including large buildings which need to be designed to withstand impacts such as high winds and natural disasters, to freight vehicles which have onboard weighing scales, weighbridges and docking locations. Load cell types include single point load cells, shear beam load cells, low profile load cells, tank and silo load cells, weighbridge load cells, on-board truck load cells and double-ended beam load cells.
Because various types of load cells are needed to operate different pieces of machinery, choosing the right load cell is important in order to maximise efficiencies, restrict downtime, lower costs and ensure accurate, consistent and reliable weighing results.
It’s best to find a supplier which isn’t limited to offering one particular brand of load cell, but which can rather provide a tailormade solution based on the application and client’s individual needs. One such supplier is AccuWeigh, Australia’s largest industrial weighing company which has extensive experience with load cells of all types and models, including load cells suitable for dynamic weighing applications.
There are many reasons that load cells are used to measure weight, and if you discuss your load cell needs with AccuWeigh, you’ll find that there are a whole lot more benefits to load cells than simply quantifying objects and materials. Call them on 08 9259 5535 or visit www.accuweigh.com.au to discover more about their extensive range of weighbridges, weighing scales and product inspection equipment.