Today's instruments typically record in the ITS-90 scale, but some old datasets will be in the IPTS-68 scale. T90fromT68() converts from the IPTS-68 to the ITS-90 scale, using Saunders' (1990) formula, while T68fromT90() does the reverse. The difference between IPTS-68 and ITS-90 values is typically a few millidegrees (see ‘Examples’), which is seldom visible on a typical temperature profile, but may be of interest in some precise work. Mostly for historical interest, T90fromT48() is provided to convert from the ITS-48 system to ITS-90.




Vector of temperatures expressed in the IPTS-68 scale.


temperature Temperature expressed in the ITS-90 scale.


P. M. Saunders, 1990. The international temperature scale of 1990, ITS-90. WOCE Newsletter, volume 10, September 1990, page 10.

See also


library(oce) T68 <- seq(3, 20, 1) T90 <- T90fromT68(T68) sqrt(mean((T68-T90)^2))
#> [1] 0.003027144