Fluke Calibration 1502A and 1504 support comparison measurements with reference temperature probes in the laboratory and field. The 1502A accepts nominal 10…100 Ω RTD, PRT and SPRT sensors; the 1504 accepts thermistors. The 1502A covers −200 to +962 °C with 0.001 °C resolution. The 1504 offers 0.0001 °C resolution, with its temperature range determined by the selected thermistor. Listed accuracy refers to the readout; probe uncertainty and characterization errors are additional. RS-232 is standard, with IEEE-488/GPIB available in -2506 versions. The 115 V or 230 V mains configuration is selected when ordering. The photograph shows the 1502A; 1504 specifications are identified separately.