Table 6.

Industrial platinum resistance thermometer calibrations. The expanded uncertainty (k = 2) is denoted by U

Comparison calibration
Comparison bath	LN2	Cryostat	Cryostat	Cryostat	Water	Oil	Salt
Temperature range	−196 °C	0 °C to −70 °C	−70 °C to −80 °C	−80 °C to −97 °C	0.5 °C to 95 °C	95 °C to 300 °C	300 °C to 550 °C
U(m°C)	2.3	2.3	4	9	2.4	4.8	7.5

Fixed-point calibration
Fixed point Temperature	ice point 0 °C	H2O TP 0.01 °C	Ga MP 29.7646 °C
U(m°C)	1.8	1.4	1.6