IEC60270 has recently undergone revision, but the scope for performance tests on calibrators remains largely the same. Three methods are applicable for determination of partial discharge (PD) calibrator charge and risetime numerical integration, passive integration, and active integration. The suitability of each method for determination of charge has been evaluated in EURAMET.EM-S36 Comparison of Partial Discharge Calibrators and is documented in its associated report. However, due to the infeasibility of deriving a comparison reference value for rise time, this metric is omitted from the comparison. Reasons for widely diverging results for rise time derivation are discussed in this paper.