[ RadSafe ] Counting Efficiencies for Helgeson (Neutron Products) Whole Body Counter

[James Barnes]

Folks;
 
I need the approximate efficiencies for the Helgeson (now Neutron Products) 
whole body counter (the "trough" version where the person laid down inside of 
the lead lined well and the counter trolly rolled above him / her)).  
Particularly I need it for I-131, Cs-134, Cs-137.  I looked in our old Helgeson 
reports, but efficiencies weren't really listed.
 
Any help (even educated guesstimates) would be useful.
 
Thanks,
 
Jim Barnes