oce (version 0.9-18)

T90fromT68: Convert between temperature scales

Description

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.

Usage

T90fromT48(temperature)
T90fromT68(temperature)
T68fromT90(temperature)

Arguments

temperature

expressed in one scale

Value

• Temperature expressed in the second scale

References

P. M. Saunders, 1990. The international temperature scale of 1990, ITS-90. WOCE Newsletter, volume 10, September 1990, page 10. (http://www.nodc.noaa.gov/woce/wdiu/wocedocs/newsltr/news10/contents.htm)

Examples

library(oce)
T68 <- seq(3, 20, 1)
T90 <- T90fromT68(T68)
sqrt(mean((T68-T90)^2))