Abstract
The second virial coefficient of helium was measured in the temperature range 0° to 600°C by an expansion procedure previously described. Within our limits of error, estimated to be approximately 0.5 percent at 0° and approximately 1 percent at 600°, the results (expressed in Amagat units of volume) are given by: 10 3 B T =0.5485–0.1315×10 −3 T+(3.754/T) where T is in °K. A comparison with existing data is given.