Two systems for collection, storage, and analysis of measurements made with RF field survey instruments.
Two systems for storage and analysis of radiofrequency (RF) radiation exposure data were evaluated. OSHA occupational RF exposure limits have specified a time weighted average over any 6 minute period, and NIOSH epidemiological studies of RF exposure also required the ability to collect and analyze data over time periods. The Holaday HI-3320 and the Gulton RR-400 Rustrak Ranger data loggers were interfaced with the RF survey instruments and evaluated for data collection, storage, and analysis capabilities. The advantages of the Holaday HI-3320 included shielding against electromagnetic interference (EMI), variable sampling period, availability of connecting cables, availability of software for uploading data to microcomputers, and storage of data in a format which allowed further statistical analysis. Expense, lack of retention of individual readings in memory, voltage input requirement, extraneous information present in data files, and low battery destruction of data were considered to be the disadvantages of the system. The advantages of the Gulton RR-400 Rustrak Ranger were software provisions for uploading, statistical analysis, and graphic output, acceptance of different types of input, and low expense. The disadvantages of the Ranger were lack of EMI shielding, 0.65 second minimum sampling time, individual data points were not logged, and requirement for an interface pod. The authors conclude that most of the problems for RF measurement applications could be solved for either data logger.