NIST Temperature Scale Database (SRD 60), Version 3.0
ITS-90 Primary Fixed Points:
International Temperature Scale Primary Fixed Points
We provide the primary (defined) fixed points on the International Temperature Scale of 1990 (ITS-90) along with uncertainties. We provide the primary references for all primary fixed points. In addition, to this primary reference, we also provide OTHER references (generally multiple) to the literature for these primary fixed points in the menu item References for Temperature Points.
Instruction:- Click on the hyperlink in the column for more information.
Substance | Transition | T90 (K)
| u(T90) (mK) | T-T90 (mK) | u(T-T90) (mK) | Squib |
More Data |
|---|---|---|---|---|---|---|---|
| He | VP | 0.65 to 5.0 | <1 | |T-T90|<2 | <1 | manage_search | |
| H2 | TP | 13.8033 | 0.15 | 0.36 | 0.01 | manage_search | |
| e-H2 | VP1 | 17.035 | 0.15 | 0.29 | 0.01 | manage_search | |
| e-H2 | VP2 | 20.27 | 0.15 | 0.16 | 0.01 | manage_search | |
| Ne | TP | 24.5561 | 0.09 | -0.06 | 0.2 | manage_search | |
| O2 | TP | 54.3584 | 0.06 | -2.21 | 0.14 | manage_search | |
| Ar | TP | 83.8058 | 0.06 | -4.21 | 0.15 | manage_search | |
| Hg | TP | 234.3156 | 0.2 | -2.89 | 0.13 | manage_search | |
| H2O | TP | 273.16 | 0 | 0.1 | 0.1 | manage_search | |
| Ga | MP | 302.9146 | 0.2 | 3.84 | 0.34 | manage_search | |
| In | FP | 429.7485 | 0.8 | 10.1 | 0.8 | manage_search | |
| Sn | FP | 505.078 | 0.6 | 11.5 | 1.3 | manage_search | |
| Zn | FP | 692.677 | 0.8 | 13.8 | 6.9 | manage_search | |
| Al | FP | 933.473 | 2 | 28.7 | 6.6 | manage_search | |
| Ag | FP | 1234.93 | 4 | 46.2 | 14 | manage_search | |
| Au | FP | 1337.33 | 25 | 39.9 | 20 | manage_search | |
| Cu | FP | 1357.77 | 25 | 52.1 | 20 | manage_search |