Table 2.

Fixed points used for calibration of Pt/Pt – 10% Rh thermocouples using eq (82) and (83)

Fixed point	Defined temperature		Nominal electromotive force (IPTS–68) [1]
	IPTS–48 [4]	IPTS–68 [1]
	°C	°C	μV
Calibrated Pt resistance thermometer	630.5
Calibrated Pt resistance thermometer	(a)	630.74	5534
Normal freezing point of silver	960.8	961.93	9117
Normal freezing point of gold	1063.0	1064.43	10300

^aAccording to eq (80), t₄₈ = 630.538 °C when t₆₈ = 630.74 °C.