[en] In the pulsed reactivity operation of the reactor ''Yayoi'' at the Nuclear Engineering Research Laboratory, University of Tokyo, the half width of output pulses is approximately 100 μs and the maximum output is 1 GW. Since high speed response and wide-range output were required for the initial output waveform measurements, new 3 channel (compensated ionization chamber (CIC) 2 channels, plastic scintillator plus photomultiplier 1 channel) linear output systems have been provided in addition to the existing 6 channels of nuclear instrumentation. The performances of these additional 3 channels and a reserve system (plastic scintillator plus photo-diode) prepared separately for the purpose of pulsed reactor instrumentation are reported. First, the outline of the detectors, power supply, amplifier system, recording system, source trip generator and others is described, and next, response test, output calibration, and the examples of measuring the characteristics in pulsed reactivity operation are explained in detail. The features of this nuclear instrumentation are listed in a table in a simple form. The CIC and photomultiplier systems did not necessarily measure the true output waveform, generated in the core because of their sensitivities and the shapes of the CIC systems though they showed excellent stability and reliability and of the poor output current of the photomultiplier. The photo-diode seems to afford comparatively true waveforms because it can be inserted into the core for the reason of its small size, low sensitivity, and high peak output current. (Wakatsuki, Y.)