In the last half of the 1970s, a variety of research reactor facilities were used to perform studies on the radiation hardness of solid-state devices. Due to the lack of a cohesive method for evaluating and measuring the relative damage effectiveness of the various environments, results of the studies varied widely, and it was difficult to compare the results from one facility with results obtained at a different facility. In response, the testing community developed a standard to evaluate an equivalent damage concept, which would provide a common basis for damage studies. ASTM E722, Standard Practice for Characterizing Neutron Spectra in Terms of an Equivalent Monoenergetic Neutron Fluence for Radiation-Hardness Testing of Electronics, has become the accepted standard for the test facilities. In this paper we document the significant changes to this response function, other functions commonly used with transport calculations, and the effect of the changes on evaluating the 1-MeV equivalent silicon displacement damage with a common set of reactor spectra. The data presented are of value to test programs that have used one or more of the facilities for an extended life-cycle test program.