原理
principle
基于阿基米德原理，测量浮子处于被测液体的表面，测量浮子的底部通常沉入液面1-2mm。此时，测量浮子受到其本身的重力和液体的浮力（阿基米德浮力原理），在测量钢丝上则表现为测量浮子所受重力和浮力之合力，即测量钢丝上的张力。
Based on Archimedes principle, the float is measured to be on the surface of the liquid under test. The bottom of the float is usually measured to sink 1-2 mm. At this time, the float is measured by its own gravity and the buoyancy of liquid (Archimedes buoyancy principle), while the steel wire is measured by the combined force of gravity and buoyancy, that is, the tension of the steel wire.
当液位静止时，测量浮子处于相对静止状态。此时，测量钢丝、测量鼓及力传感器以杠杆滑轮原理构成力平衡。
When the liquid level is still, the measurement float is in a relatively static state. At this time, the measuring steel wire, the measuring drum and the force sensor constitute the force balance based on the principle of lever pulley.
当液位下降时，测量浮子所受浮力减小，则测量钢丝上的张力增加，张力的改变立即传达至力传感器的张力丝上，使其拉紧，检震器检测到张力丝上的频率增加，伺服控制器随即发出命令，令伺服电机带动测量鼓逆时针转动，伺服电机以0.05mm的步幅放下测量钢丝，测量浮子不断地跟踪液位下降的同时，计数器记录了伺服电机的转动步数，并自动地计算出测量浮子的位移量，即液位的变化量。
When the liquid level drops, the buoyancy of the measuring float decreases, and the tension on the measuring steel wire increases. The change of tension is immediately transmitted to the tension wire of the force sensor to tighten it. The frequency of the tension wire increases when the vibration detector detects it. The servo controller then issues an order to make the servo motor drive the measuring drum to rotate counter-clockwise. The servo motor lowers the measuring steel wire at a 0.05mm step. The float keeps tracking the drop of the liquid level. At the same time, the counter records the rotating steps of the servo motor and automatically calculates the displacement of the measurement float, i.e. the change of the liquid level.
当液位上升时，这个过程相反。
When the liquid level rises, the process is reversed.