ICRU Report 37, Radiological Health Handbook

[steven t hand <hand@wam.umd.edu>]

I need some help with film badge information:		

ICRU Report 37 lists on page 114 the average range of electrons in
A-150 tissue equivalent plastic, a chart of these is shown in the 	
Health Physics and Radiological Health Handbook page 184 - 185.

Please, some assistance with the interpretation of these charts as	
related to the data.  The covering on the film for our monitoring has
a thickness of 35 mg/cm sq plastic ( I am assuming for the moment that
it is the A-150) and the skin thickness is 7 mg/cm sq.  I am looking 
for the energy of the beta particle under which monitoring would not
be useful, feasible, practical based on this information.  We currently
do not monitor for H-3, C-14, and S-35, however the data on page 114 of
the ICRU document lists a .150 MeV beta as having an average range of
0.03 mg/cm sq (rounded up).  I am confused by this information.  Does the
factor of 8x thickness for the plastic have to do with this ?  Is there
also a limit to the thickness of the plastic around the film to keep 
light from entering?  I am sorry for the reference to the chart for those
of you who do not have the handbook or ICRU 37.

I have a query into our vendor as well.

Thank you.

steve at UMCP