NEWS

Bench scales, also known as tabletop or platform scales, are widely used in retail, laboratories, warehouses, and light industrial environments. At the heart of these weighing systems is the single point load cell, a sensor specifically designed to deliver accurate measurements even when loads are placed off-center. Selecting the right single point load cell for a bench scale is essential for achieving long-term accuracy, reliability, and compliance with application requirements.

Understand the Bench Scale Application

Before choosing a load cell, it is important to clearly define how the bench scale will be used. Typical bench scale applications include counting, portion control, quality inspection, and packaging. Each application places different demands on capacity, accuracy, and durability. Environmental factors such as temperature changes, humidity, dust, or washdown requirements should also be considered at the selection stage.

Determine the Required Capacity

Capacity is one of the most critical parameters when selecting a single point load cell. The rated capacity should exceed the maximum expected load, including the weight of the platform and any containers. As a general guideline, choosing a load cell with a capacity 20–30% higher than the maximum working load helps protect the sensor from overload and ensures stable performance over time.

For example, if a bench scale is designed to weigh up to 30 kg, a 40 kg or 50 kg single point load cell may be a suitable choice.

Consider Platform Size and Off-Center Load Performance

Single point load cells are designed to support a platform of a specific maximum size while maintaining accuracy for off-center loading. Manufacturers usually specify the maximum platform dimensions for each model. Selecting a load cell that matches or exceeds the platform size of the bench scale ensures consistent readings, even when the load is placed near the edges or corners.

This factor is especially important in bench scales, where users often place items quickly and not always in the center.

Evaluate Accuracy and Resolution Requirements

Accuracy requirements vary depending on the application. Bench scales used in laboratories or quality control environments typically require higher precision than those used for general industrial weighing. Key specifications to review include non-linearity, hysteresis, repeatability, and combined error.

If the scale needs to display small weight increments, selecting a load cell with higher sensitivity and better repeatability will help achieve the desired resolution.

Choose the Right Material and Protection Level

The material of the load cell should match the working environment. Aluminum single point load cells are commonly used in dry, indoor bench scale applications due to their cost-effectiveness and good performance. Stainless steel load cells are better suited for humid, corrosive, or washdown environments, such as food processing or pharmaceutical applications.

Ingress protection ratings, such as IP65 or IP67, indicate resistance to dust and water and should be selected based on environmental exposure.

Check Mounting and Mechanical Compatibility

Proper mounting is essential for accurate weighing. Ensure that the selected single point load cell is compatible with the bench scale’s mechanical structure. This includes checking mounting hole patterns, load introduction points, and recommended installation methods. Following the manufacturer’s mounting guidelines helps minimize mechanical stress and measurement errors.

Review Electrical Specifications and Certification

Electrical output, typically expressed in mV/V, must be compatible with the scale indicator or controller. Cable length, shielding, and connection type should also be considered for reliable signal transmission.

For commercial bench scales, compliance with relevant standards and certifications, such as OIML or NTEP, may be required. Selecting a certified load cell can simplify system approval and market access.

Conclusion

Selecting a single point load cell for a bench scale requires a balanced evaluation of capacity, platform size, accuracy, environmental conditions, and mechanical compatibility. By carefully matching the load cell specifications to the real-world application, users can ensure stable performance, accurate measurements, and long service life. A well-chosen single point load cell is the foundation of a reliable and efficient bench scale system.