Can the rad-D tell me when radiation levels are hazardously high?
Yes. The rad-D displays an alarm level of 1 through 9. This value tells you the number of photons being measured at the detector. At the point where the displayed alarm goes from an 8 to a 9 is equivalent to a dose rate of at least 8 mrems/hour. To determine whether the detected radiation source is at a hazardous, you need to find the range from the source where the rad-D display switches from an 8 to a 9. Once the range is known, it is easy to determine an approximate dose rate on a reference card.
