Continuous monitor of dangerous levels of microwave power

High mortality rates have been observed when animals arc exposed for up to 100 min in r.f. radiation having frequencies greater than 10 MHz and power densities of the order of 100 mW/cm2. A safety level of 10 mW/cm2 for frequencies above 10 MHz and exposures of the order of 5 min has therefore been generally adopted. A continuously monitoring small-size instrument for dangerous maximum and average levels of microwave power is required, particularly if it can be carried in the pocket of a person in a similar manner as the well known X ray photographic monitor.