Advantages and Disadvantages of Load Cell and Its Development Trend

Advantages and Disadvantages of Load Cell and Its Development Trend

A load cell is a sensor device used to measure the force of an object. It measures the weight of an object by checking the load carried by the load-bearing body. The load cell converts the pressure exerted on the load-bearing body by the object into an appropriate electrical signal, thereby achieving the purpose of measurement.

The weighing principle of load cell sensors

Load cell sensors use metal strain gauges to form a measurement bridge. Metal resistance wires are stretched and become thinner under tension, causing an increase in resistance, i.e. the metal resistance changes with the applied strain force. Therefore, if the metal wire is firmly attached to the measured object, the measured object will stretch or contract under external force, and the metal resistance wire will stretch or contract proportionally, and its resistance value will also be changed accordingly.

The Characteristics of Load Cell Sensors:

Advantages:
Low sensitivity to changes in the loading point
Good anti-skewed load performance
Good inherent linearity
Easy installation
Fixed without rotation
Low manufacturing cost

Disadvantages:
High center of gravity
Poor overload capacity
Large-scale weighing sensors are difficult to achieve high accuracy grades

The limitations of load cells:

Resistant to impact, overload, and easy to install: Each sensor sends its own signal, which is processed separately by a dedicated module. If multiple sensors are used to form a scale, there is no need to worry about the effects of uneven loading, thus providing overall measurement accuracy for the weighing system.
Digital signal output: The sensors output digital signals in units of kg and g, making on-site calibration relatively simple. Even without calibration, they can achieve high accuracy, especially in large-tonnage tank or inappropriate calibration situations.
Digital signal transmission: Digital signal transmission means that on-site electromagnetic interference has no effect on the signal, making the system more reliable.
High resolution: Each load cell has a resolution of up to 50,000 divisions, making it suitable for building more precise weighing systems.
Easy to replace: The signal is transmitted via RG58 coaxial cable, so if the sensor cable is cut, the user can simply purchase the cable and replace it on site without having to return the sensor to the factory for repair.
No calibration required: After replacing the sensor, the entire weighing system does not need to be recalibrated, greatly simplifying the maintenance workload.
Resistant to pipe deformation: Pipelines in tanks and containers often cause weighing errors, mainly because traditional strain-based load cells generate significant deformation when under load, causing additional forces to act on the weighing vessel. However, the MD series sensors have a maximum deformation of less than 0.1mm, so they are less affected by pipe deformation, providing a more reliable overall weighing performance.

The applications of load cells

Load cells are not only used to measure the weight of objects, but also in many other fields. For example, in modern science and technology industry, the principle of load cells is similar to that of pressure sensors, but the shape is different.