How Do Planar Beam Load Cells Work?

Planar beam load cells operate based on the principle of elasticity, where the material deforms under the influence of an applied load or force. The deformation is typically minute, and barely visible to the human eye.

The core component of a planar beam load cell is the strain gauge, an electrically conductive device that alters its electrical resistance when subjected to strain. When a force is exerted on the load cell, the strain gauges - bonded securely to the load cell - also deform. This deformation, in turn, alters the electrical resistance of the strain gauges. Importantly, the change in resistance is directly proportional to the amount of strain, i.e., the weight or force applied.

These changes in resistance can be accurately measured through accompanying electronic components. The readings are then converted into an output signal, which can be processed further and translated into a weight or force measurement.

Types of Planar Beam Load Cells

Planar beam load cells typically have a fixed design, however, differences in design allows for the sensor to be used in different situations. Differences result in the following types:

• Standard Planar Beam Load Cells: These are the most common type of planar beam load cells and have a standardised size and capacity. They are used in a wide array of general weighing applications, including retail scales, medical scales, and postal scales.
• Miniature Planar Beam Load Cells: Compact and lightweight, these cells are ideal for applications where space is limited or where minimal impact on the mechanical design is required. They are typically used in medical devices, portable equipment, and small-scale laboratory apparatus.
• High-Capacity Planar Beam Load Cells: These load cells are designed to handle larger loads and are often used in industrial applications. They have a robust construction to withstand the rigours of heavy-duty use.
• Custom Planar Beam Load Cells: Designed and manufactured to meet specific customer requirements, these could include unique sizes, shapes, capacities, or environmental protection needs. They are typically used in specialised applications where off-the-shelf products may not suffice.

Planar beam load cells, owing to their unique structure and high performance, have gained prevalence in numerous industries, and continue to be a go-to choice for various weighing applications.

Typical Applications of Planar Beam Load Cells

• Retail Scales: Planar beam load cells are often the preferred choice for retail scales due to their low-profile design and high precision, combined with relatively low cost.
• Medical Equipment: In the medical industry, where precision and space constraints are critical factors, planar beam load cells are used in various types of equipment, including patient weighing systems and medical infusion pumps.
• Postal and Parcel Weighing: Planar beam load cells are used in postal scales and parcel weighing systems for their ability to provide accurate readings and their slim form factor, which fits well within the design of these scales.
• Airport Baggage Scales: The robust design and high capacity of planar beam load cells make them ideal for airport baggage scales, which need to withstand heavy loads and frequent use.
• Industrial Weighing Platforms: Planar beam load cells are used in industrial applications where large platform scales are required. The robust nature of the sensor allows for heavy, industrial usage.

These typical applications reflect the versatility and high performance of planar beam load cells, highlighting their key role in various industries where precise weight measurement is critical.