[for cleanup it is currently being assumed that IMP = soil (1:1)] Correcting for brush does not necessarily correct for the difference Church: Remeasured islands show higher IMP readings (more realistic) IMPS are consistent Are using corrected values for clean-up decisions. What is the standard calibration frequency? Healy requested a report on methods of calibration - Am-241 source placed in an area to determine angular response EG&G did theoretical calibration Concerned if there is no ground flat source calibration For calibration: should move point source around and use absorbers