An experimental setup established for the calibration of temperature and pressure data loggers for use in the characterization of autoclaves and steam sterilizers is described. The results obtained on two devices in the range of 25 • C to 125 • C at absolute pressures from 100 kPa to 375 kPa are presented and discussed in the context of the manufacturer's specifications and their suitability for on-site characterization of the temperature and pressure conditions during the normal operational cycles. The recommendations on the calibration of these devices and the estimation of the contributions to the expanded uncertainty of measurement for the characterization of autoclaves are addressed.