factory supplying 400m 500 m portable steel ruler water level meter better import ruler material longer life span depth meter

the preparation of the movable steel ruler water level gauge is as follows: loosen the tightening screw behind the reel, let the reel rotate y, press the power button (the power supply is always on), and put the probe into the water pipe. hold the steel ruler cable and let the probe move slowly downward. when the contact of the probe touches the water surface, the sound of the receiving system will emit a continuous beeping sound. the distance of the mouth.