Jim,
There’s a lot of folks around the country who bought surplus Civil Defense radiation meters.
What they don’t understand is the CDV-715, CDV-717 and CDV-720 meters WILL NOT measure background radiation and are useless if they are watching for increased radiation from Japan. Only the CDV-700 will measure background radiation.
According to an LAFD document: “Radiological survey instruments, if available, are recommended for initial entry to the site. Before entering the accident area, determine the background radiation level using the CD V-700, or a similar survey instrument.”
Background radiation levels cannot be determined using the CD V-715 or other high-range gamma-detecting instruments; therefore, a ‘positive response on high-rage’ meters such as these should stimulate immediate rescue and medical intervention.
I found this misunderstanding by my fellow man to be of concern and thought you might post it. Best regards to you and yours, – John