The new International Temperature Scale of 1990 (ITS-90).
A new international temperature scale, the ITS-90, will replace the International Practical Temperature Scale of 1968 (amended edition of 1975), IPTS-68(75), on 1 January 1990. Temperatures on the ITS-90 will agree more closely with thermodynamic temperatures; therefore, the ITS-90 represents a substantial improvement over the IPTS-68(75). Fortunately for the clinical laboratory community, the change in the scale will be at most only 0.05 degrees C or less in the range from 0 to 60 degrees C, but corrections in primary calibrations should be made so that the calibrations are based on the ITS-90.
Mangum
B W
BW
Temperature and Pressure Division, National Institute of Standards and Technology, Gaithersburg, MD 20899.
D002138:Calibration; D013696:Temperature; D013816:Thermodynamics; D013821:Thermometers; D014894:Weights and Measures