The invention relates to the logical pen of the acousto-optic indicator with the twelve frequency sections which has the three characteristics when it detects the impulse signal: (1) the frequency of the impulse signal is divided into twelve frequency sections according to the decimal mode and indicates the frequency section of the detected signal by combining the two indicating information; one the one side, it indicates the dimension frequency section of the detected signal by dividing to four dimension frequency sections(hertz, kilohertz, megahertz, gigahertz); on the other side, it indicates the magnitude of the detected signal by dividing to three magnitudes(one, ten and hundred) according to the decimal mode in every dimension frequency; (2) it indicates the dimension frequency sections and the magnitude of the detected impulse signal by the luminescent indicator of four different color and three different flicking speed; (3) it indicates the dimension frequency sections and the magnitude of the detected impulse signal by the acoustic indicator of four different tones and three different cutting speed. |