# ITS-90 4He vapour pressure equation coefficients (1.25 K to 2.1768 K)
Coefficient	Value
A0	1.392408
A1	0.527153
A2	0.166756
A3	0.050988
A4	0.026514
A5	0.001975
A6	-0.017976
A7	0.005409
A8	0.013259
A9	0.0
B	5.6
C	2.9