High-Precision Digital Load Cell

Traditional analog load cells have the disadvantages of small analog signal, short transmitting distance, weak anti-interference ability and inconvenient installation. Moreover, with the advent of the information epoch, more and more testing tasks require computers as the test platform, to achieve highly accurate, fast, diversiform and flexible tests. So the trend that development of sensors toward small, modular, digital, intelligent and network is inevitable. Compared with analog load cells, digital load cell of the advantages of high reliability, strong anti-interference, high sensitivity, lightning performance, high communication speed and anti-cheat effect makes it the trend of sensors development.For some existing problems in analog load cells, such as weak anti-interference ability, short transmission distance, and low accuracy of some kinds of digital load cells, a current digital load cell system is established; whose accuracy can reach 0.05uV/10mV (5/1000000).The design fully integrates the function of hardware system and software system, makes use of fully differential signal conditioning, ratio measurement technology, AC excitation principle and digital filter technology to greatly reduce the system hardware requirements and the system costs; Moreover, the design uses of 32-bit microprocessor for digital signal processing to achieve the function of linear adjustment, temperature compensation and digital filtering which can improve the system precision, linearity and stability. Last, this design uses a unique digital filter technology which enables digital filter to maintain a high filtering performance in the premise of a short settling time to ensure that the data measured in real time. Verified that the design basically achieve the accuracy requirement of system.