A system and method for testing a multimeter provides a mechanical arm to set a gear of the multimeter. Values displayed on the multimeter are captured by a camera. The computer obtains the displayed values from captured images using a difference image method. If a difference between each two obtained values is in an allowable error range of the multimeter, the computer displays that the gear is qualified. If the difference between each two obtained values is not in the allowable error range, the computer displays that the gear is out of tolerance.