These equations are called ITS-90
inverse polynomials because they determine temperature from voltage.
The realization of the International Temperature Scale of 1990 (ITS-90
) at METROSERT (Fig.
The thermometer conforms to ITS-90
International Temperature Standard.
For example, our lowest temperature of 24.5561 K is the value assigned to the triple point of neon in the International Temperature Scale of 1990 (ITS-90
The worldwide consistent temperature measurement is assured by the International Temperature Scale of 1990 (ITS-90
), which extends from 0.65 K to the highest temperatures, measurable with the aid of Planck's radiation law.
These estimates of [delta][DELTA][T.sub.pp] include a contribution associated with the ITS-90
thermocouple inverse polynomials (e.g., Omega ).
Hart adds that Met/Temp II also enables users to perform ITS-90
coefficient and residual calculations and generate corresponding tables and reports.
Callendar-Van Dusen coefficients for common RTD alphas Standard RTD Temperature A Coefficient ([alpha]) DIN 43760 0.003850 3.9080 [10.sup.-3] American 0.003911 3.9692 [10.sup.-3] ITS-90
0.003926 3.9848 [10.sup.-3] Standard B C * DIN 43760 -5.8019 [10.sup.-7] -4.2735 [10.sup.-12] American -5.8495 [10.sup.-7] -4.2325 [10.sup.-12] ITS-90
-5.870 [10.sup.-7] -4.0000 [10.sup.-12] * Used for temperature less than 0[degrees]C only.
PRTs may be read using the standard DIN curve or individually calibrated probes may use ITS-90
coefficients for higher accuracy.
These databooks are denoted as: 1 - Realising ITS-90
, Primary Laboratory; 2 - Secondary Laboratory Equipment; 3 - Industrial Laboratory Equipment; 4 - Blackbody and Thermocouple Reference Equipment; and 5 - Training and Services.
IF97 is based on the latest standard temperature scale, ITS-90
, which is a small improvement toward better representing physical reality.