The single channel analyzer (SCA) that was being used for validating events from the well counter had one major flaw: there was no way of visually verifying either the starting point or the extent of the energy window, and therefore no way of being absolutely certain that the right energies were being counted. At one point the severity of this problem was brought home when the window was changed accidentally, and this change was not detected for several days.
In addition, two multichannel analyzers with displays were available, but due to the age of the instruments, neither one had an appropriate computer interface.