Maintenance of condenser-ion chamber calibration

Readings made with condenser-ionization chamber systems are frequently suspect because significant changes in calibration can occur without being evident in the normal use of the instruments. These changes can be traced to physical causes that alter the voltage sensitivity of electrical capacitance. Thus, measurement of these electrical parameters will indicate whether or not a change in calibration has occurred. Formulas are presented of calculating such changes and determining which parameter is responsible. Good agreement was obtained between the results of calculations with these formulas and the results of radiation measurements made with a Victoreen Condenser R-Meter after several components had been deliberately maladjusted.