A new pulse amplitude discriminator, especially suitable for counting experiments, has been developed. Ten units were built and tested, and all of the threshold temperature coefficients are in the range −0.03 to +0.12mV per °C. At very high rates the threshold is stable and the output pulse width and the dead time change negligibly. Since the unit incorporates a number of convenient features, including provision for automatic dead-time correction, it is an extremely versatile instrument.

A true random ratemeter which automatically corrects for dead time is described. The unit requires two inputs: the normal pulse input and a signal whose duration equals the dead time of the channel being monitored. Variations in dead time, whether they are random or not, are automatically accommodated. Accuracy is 1 % on all ranges even at duty factors up to 99%.