Instrument nonlinearities and therapy unit timer error.
D003036:Cobalt Isotopes / Q000627:therapeutic use; D004553:Electric Conductivity; D011137:Polystyrenes; D011867:Radioisotope Teletherapy / Q000295:instrumentation*; D011879:Radiotherapy Dosage; D013997:Time Factors
D003036:Cobalt Isotopes; D011137:Polystyrenes