Digital load cells (referred to as digital sensors) are a new type of load cell developed on the basis of traditional analog load cells. Compared with analog sensors, they have high reliability, digital cores with protection circuits, fault alarm indications, good consistency, no need for calibration, and easy adjustment of Angle differences. It features long transmission distance, fast communication speed, remarkable anti-cheating effect and reduced usage cost. Therefore, it is currently highly favored in the weighing instrument industry. In order to better apply digital sensors, it is very necessary to conduct research on the working principle and application skills of digital sensors.

The working principle of digital load cells

Traditional analog load cells output analog signals. As the name suggests, digital load cells output digital signals. Due to the inherent disadvantages of analog load cells such as small output analog signals, short output distance, poor anti-interference ability, and inconvenient installation and adjustment, as early as the 1980s, people built amplification and A/D conversion circuits inside the sensor housing, that is, analog sensor + digital transmission (amplification and A/D circuits). It formed the first generation of "digital load cells", overcoming the shortcomings of analog load cells such as small signal, short transmission distance and poor anti-interference ability. However, since the various indicators of the sensor are determined by its own manufacturing, compensation and adjustment processes, its original functions have not been broken through. At present, this type of sensor is widely used. The second-generation digital load cell is based on the first generation and adds intelligent compensation of sensor software, which is called a digital intelligent load cell. Through digital compensation circuits and processes, linear, hysteresis, creep and other compensations can be carried out. It is equipped with a temperature sensor, and real-time temperature compensation can be performed through compensation software. The address is adjustable, which is convenient for application and interchangeability, as well as remote diagnosis and correction. Overall, the digital intelligent sensors at this stage are mainly reflected in the intelligent compensation and correction of the sensors themselves. However, strictly speaking, the intelligence of digital intelligent sensors is not only reflected in the intelligent compensation and correction of the sensors themselves, but more importantly, it is to achieve the intelligence of the application.

The third-generation digital intelligent load cell is composed of analog sensors, digital transmitters (amplification and A/D conversion), sensor software compensation and intelligent automatic control software. It has a sensitive function. It can complete all or most of the functions such as weighing signal detection and processing, logical judgment, closed-loop control, bidirectional communication, cyclic self-check and self-diagnosis, automatic correction and compensation, and automatic calculation, overcoming the shortcomings of the second-generation digital load cell. It can be either an integral integrated structure or a separable modular structure. The latest third-generation digital intelligent load cell has been applied in various intelligent closed-loop control, multi-purpose, multi-component measurement, high-speed dynamic digital signal processing and network communication scenarios.