ppm
Estimate of the relative standard deviation of the mean of the fit to eq (1)	2.63
Estimate of the relative standard deviation of the mean of the thermal expansion	1.5
Estimate of the relative uncertainty of the dead space effect (1 standard deviation)	0.3
Estimate of the relative uncertainty of the gas imperfection correction (1 standard deviation)	0.3
Estimate of the relative uncertainty of the pressure ratio in addition to the first item (1 standard deviation)	0.5
Estimate of the total relative standard deviation of the steam point:.	3.1
Estimate of the total relative uncertainty of the steam point at the 99 percent confidence level (3 standard deviations): 9.3 ppm or 3.5 mK