Fathometer is used to measure Ocean depth. Fathometer is a depth finder that uses sound waves to determine the depth of water. The Richter Scale is used to measure the intensity of Earthquakes. A rain gauge (also known as an odometer, pluviometer, or an ombrometer) is an instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over a set period of time. A sound level meter is used to measure acoustic/Sound intensity.