The study and implementation of connected liquid level detection technology applying to medical equipment

A liquid level detection technology for medical devices is introduced. Based on the principle of capacitance detection, the design uses a single needle as the liquid level detection probe to achieve automatic liquid level detection. In the design, a 32-bit high-performance processer, STM32 is used for the system controller. The detection system consists of detection circuit and signal processing unit. The detection circuit includes a capacitance detection circuit, a band pass filter and a differential amplification circuit. The system has been employed in a fully automatic chemiluminescence immune analyzer. A lot of experiments prove that the design can achieve 10 μL liquid level detection in a diameter of 1 cm micro tube and it has a better practicability and stability.