an instrument that measures the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute
轉速表
motorsports、motor sports、racing、rev counter、revolution-counter、RPM、rpm gauge、speed、tach、tachometer
賽車、賽車運動、賽跑、吼tsounter、革命櫃檯、RPM、轉速表、速度、轉速表、轉速表
資料來源：openclipart ( https://openclipart.org/ )