‘Weighing in’ on Load Cell components and application within industry.
The market for load cells is anticipated to expand over the next four years and is expected to reach approximately $1.75bn by 2024! Load cells have a wide array of industry applications including agricultural, inventory management, oil/gas, medical, construction, robotics, and many more. Here we take a look at the common types of Load Cells, their components and their functions within these industries.
A load cell is a force transducer. It converts a force such as tension, compression, pressure, or torque into an electrical signal that can be measured and standardized. As the force applied to the load cell increases, the electrical signal changes proportionally. The most common types of load cell used are hydraulic, pneumatic, and strain gauge.
Strain gauge - most often found in industrial settings. It is ideal as it is highly accurate, versatile, and cost-effective. Structurally, a load cell has a metal body to which strain gauges have been secured. The body is usually made of aluminum, alloy steel, or stainless steel which makes it very sturdy but also minimally elastic.
Pneumatic - designed to automatically regulate the balancing pressure. Air pressure is applied to one end of the diaphragm and it escapes through the nozzle placed at the bottom of the load cell. A pressure gauge is attached with the load cell to measure the pressure inside the cell. The deflection of the diaphragm affects the airflow through the nozzle as well as the pressure inside the chamber.
Hydraulic - uses a conventional piston and cylinder arrangement with the piston placed in a thin elastic diaphragm. The piston doesn't actually come in contact with the load cell. Mechanical stops are placed to prevent over strain of the diaphragm when the loads exceed a certain limit. The load cell is completely filled with oil. When the load is applied on the piston, the movement of the piston and the diaphragm results in an increase of oil pressure. This pressure is then transmitted to a hydraulic pressure gauge via a high pressure hose. The gauge's Bourdon tube senses the pressure and registers it on the dial. Because this sensor has no electrical components, it is ideal for use in hazardous areas. Typical hydraulic load cell applications include tank, bin, and hopper weighing.
Piezoelectric - works on the same principle of deformation as the strain gauge load cells, but a voltage output is generated by the basic piezoelectric material – proportional to the deformation of the load cell. Useful for dynamic/frequent measurements of force. Most applications for piezo-based load cells are in the dynamic loading conditions, where strain gauge load cells can fail with high dynamic loading cycles. The piezoelectric effect is dynamic, that is, the electrical output of a gauge is an impulse function and is not static. The voltage output is only useful when the strain is changing and does not measure static values.
Load Cell Calibration - Load cells are an integral part of most weighing systems in industrial, aerospace and automotive industries, enduring rigorous daily use. Over time, load cells will drift, age and misalign; therefore, they will need to be calibrated regularly to ensure accurate results are maintained. A five step calibration process is usually sufficient for ensuring a device is accurately calibrated. Repeating this five-step calibration procedure 2-3 times is recommended for consistent results.
Measured Results - By measuring and managing product usage in near real time, our load cell technology allowed one of our client’s supply decisions to be made proactively rather than reactively. This meant that shifts in demand were easily recognized and responded to. In turn, it reduced service interruptions, allowing their healthcare workers to focus on patient care.
If you’re looking for a load cell manufacturer or want to understand more about the use of load cells take a ‘load off’ call us today!