An improved single-blow model with nonuniform radial temperature distribution was developed and employed to measure the thermal performance of a Gifford-McMahon regenerator. In the present study, a test facility was established to conduct the single-blow measurement for evaluating the thermal performance of the regenerator with large NTU values (NTU greater than or equal to 150). A comparison on the NTU value of the test regenerator between this improved model and two prior models is shown. Empirical correlations were presented to show the relationships of the friction factor and the Nusselt number vs, the Reynolds number for the test regenerator.