were carefully instructed, with emphasis placed upon handling care, adequate field monitoring could be accomplished, 2,4.9 AM-1 The Eberline beta-gamma continuous air monitors functioned adequately during the entire Operation. However, the background monitoring probes didnot perform properly, It was thought that the probe assembly had a high voltage ground,but the probe could not be dismantled to remedy the situation, 2.4.10 TN-4D The TN-4D background monitor and recorder was used by the U.S. Public Health Service to record off-atoll radiation levels, It pos- sessed sensitive electronic circuit that caused trouble, primarily due to failure of the recorder. The Evershed recorder, Mark II, drive mo- tor gears stripped frequently, andit was necessary to replace the motor and enclosed main drive gear box. Only a few spare motors were avail- able, 2.4.11 FS-3 The Eberline film badge evaluation and recording system, FS-3, required the attention of a technician several hours daily to clean contacts, check tubes, and make miscellaneous adjustments. During the early phase of the operation the high voltage power supply caused trouble, until filtering was improved, The maximum, and only, voltage that could be obtained fromthe power supply was approximately 1275 volts, 10 It is felt that 1400 volts