Guidelines for realizing the International Temperature Scale of 1990 (ITS-90)

Calibration of Thin-Film Platinum Sensors for Use in the JILA Sr II Clock

“…Two SPRTs were used to determine the bath temperature. The reference thermometer, serial number 4386, and check thermometer, serial number 4388, have both been calibrated according to ITS-90 definitions [7] in the TMG's SPRT calibration laboratory [8]. The water comparison bath is a special deep-well custom-designed forced-circulation bath built by Hart Scientific for NIST with a 42 L working volume.…”

The Gage block handbook

“…First, the SPRT is calibrated using methods described in NIST Technical Note 1265 [44]. Second, the bridge is calibrated as described the K -"tpfV (6.10) and thus Given this fact, phase shifts must be measured indirectly.…”

Standard Platinum Resistance Thermometer Calibrations from the Ar TP to the Ag FP

“…The ITS-90 defines temperature through a set of specified thermometric fixed points, interpolation instruments, and interpolation equations [3]. Over the range from the Ar TP to the Ag FP, the interpolation instrument is a platinum resistance thermometer constructed with a strain-free platinum resistance element and meeting certain performance criteria.…”

“…Note. NIST added subscripts to the ITS-90 coefficients as a means to easily identify the calibration range of the SPRT [3].…”

“…The National Institute of Standards and Technology (NIST) is in charge of realizing, maintaining, and disseminating the International Scale of 1990 (ITS-90) [1][2][3][4][5]. The Standard Platinum Resistance Thermometer (SPRT) Calibration Laboratory of the NIST Thermometry Group realizes the ITS-90 from the argon triple point (Ar TP, -189.3442 °C) to the silver freezing point (Ag FP, 961.78 °C) for the calibration of SPRTs.…”