This is a 100-meter steel ruler water level meter used for measuring water depth in wells and boreholes. [1, 2]
Functionality: It features a probe that lowers into a well; when the probe touches water, it activates a light and audible signal to indicate the depth.
Measurement: The tape is typically marked in meters or feet to provide accurate readings for surveyors and borehole drillers.
Components: The device consists of a stainless steel probe, a reel with a handle for easy deployment, and a housing that often includes a voltmeter. [1, 2, 3, 4, 5]