For the measurement of neutron fluence rate in reactor and reliable assurance of γcount measurement of activated 55 M n-58 Ni alloy irradiated foils in reactor ,9-channel amplifier-discriminator was developed . The main technical parameter test and application test show that the gain of each channel amplifier-discriminator is continuously adjustable from 1 to 21 , the threshold of each discriminator circuit is continuously adjustable ,the maximum count rate and sensitivity of discriminator circuit are high , and the system has stable property ...