Hi,

I am currently using Subway Enviornmental Design Handbook from 1974. I am following the design sample within the book and have found out that some of the calculation do not make any sense.

In section 3-91, the ß(T) values provided by the book on the Post Portal Transient look amusing since the equations provided do not dervie the same answer as indicated in the table.

I was using the equations as shown in the attachments below

I have no idea why 0.137 can be achieved for ß(T) whem T = 20.

ß(T) = 0.080 is from Portal Entry calculation.

Can someone give me a hand on what can be happened?