The working principle of the system

The working principle of the system is summarized as follows: the system USES pressure sensors to convert the water pressure signal into a weak electrical signal at the millivolt level. The size of the electrical signal reflects the height of the liquid level. After converting the signal into analog and digital, the available voltage signal of the computer acquisition system is obtained. The change of the liquid level can be intuitively displayed in the way of Numbers and curves on the operation interface. The level control is to compare the collected level with the level set on the interface to form a negative feedback. The computer sends out a digital signal to control the on-off of the inlet valve and outlet valve, so that the actual level reaches the set level. The mechanical part consists of a water tank and an inlet/outlet pump. The non-linear water pump is used for the water outlet and the water inlet, with only two working states of on and off, which is used to automatically or manually add and release water into the container during the experiment. The computer measurement and control part is composed of pressure sensor, stc89c52 MCU, water pump control circuit, computer and the software system running on it. The sensor module has completed the A/D conversion, and the computer and the software system running on it are responsible for real-time display and control of liquid level height. .