Which method is NOT typically used to measure water level?

The magnetometer is not typically used to measure water level directly. Instead, it is a device that detects and measures the strength and direction of magnetic fields. While it can be used in geological surveys and environmental investigations to locate metallic objects or determine geological formations, it does not have the capability to measure water levels in wells or other bodies of water.

In contrast, methods like wetted tape, air line, and electronic sensor systems are specifically designed for water level measurement. Wetted tape relies on the principle of measuring the height of water by the tape being wetted up to the water surface. The air line method involves using a pressure sensor connected to a tube that allows air to be compressed by the water column, enabling calculations of water depth. Electronic sensor systems, including radar and ultrasonic sensors, provide precise water level measurements through various technologies that analyze the distance to the water surface.

Thus, identifying the magnetometer as the method that is not typically used to measure water level is accurate, given the specialized functions of the other methods.