A load cell is actually a device that converts a mass signal into a measurable electrical output. This is essential for the correct choice of load cell, as it has a bearing on its ability to work properly and its safety and service life, as well as the reliability and safety of the whole scale. There are qualitative differences between the old and new national standards in terms of the basic concepts and evaluation methods of the main technical indicators of load cells.

Traditionally, load cells were used as a generic term for load cells and force sensors, and their metrological characteristics were evaluated using a single parameter. The old national standard will be applied to the object and use of environmental conditions completely different "weighing" and "force" two kinds of sensors into one to consider, the test and evaluation methods are not given a distinction. The old national standard has 21 indicators, are tested at room temperature; and non-linearity, hysteresis error, repeatability error, creep, zero point temperature additional error and rated output temperature additional error in six indicators to determine the accuracy of the load cell level, respectively, with 0.02, 0.03, 0.05 said.

A force transducer used on weighing machines. It converts the gravitational force acting on the object to be measured into a measurable output signal in a certain proportion. Taking into account the impact of gravitational acceleration and air buoyancy on the conversion in different places of use, the performance indicators of load cells are mainly linearity error, hysteresis error, repeatability error, creep, zero point temperature characteristics and sensitivity temperature characteristics.

A load cell usually consists of a spring element on which a strain gauge is placed. The spring element is usually made of steel or aluminium. This means that it is strong, but has very little elasticity. As the name suggests, "spring element" means that the steel deforms slightly under load, but then returns to its initial position and is elastic for each load. These small changes can be obtained by means of strain gauges, the deformation of which is interpreted by the analysis electronics to determine the weight. So how should you choose a load cell?

1. Capacity: In addition to the measured load to be measured, the initial load, the impact factor and the load eccentricity factor should also be taken into account. The capacity of the load cell selected should therefore be at least 10% higher than the load to be measured.

2. Dynamic range: In the practical application of electronic weighing systems, several load cells are often used at the same time, so the load cells are generally designed to operate at around 80% to 85% of the rated load, which leaves a safety margin and ensures their accuracy in use. If you choose a very high capacity sensor, you may not be able to measure very small loads very accurately. As a rule of thumb, the load to be measured should be between 10% and 90% of the rated capacity.

3. Shape: The shape of the load cell depends largely on its application and mounting arrangement. For example, the S-shape is suitable for applications where forces are applied at both ends, while the diaphragm type is suitable for applications where forces are applied at one end only.

4. Selection of the sealed state of the load cell: The harsher environment of use often requires the selection of a sealed load cell to protect the sensor from the external environment. Citing electronic load cells, such as humidity, dust, corrosive gases, etc., so that the accuracy and stability of the measurement can be guaranteed.

Attention should also be paid to other specifications such as rated output, temperature range, error and protection class