It should be understood that the counts per minute measurements listed for the items in the collection are very approximate. They are intended to provide only a very gross approximation of how "hot" the items are. The measurements have many limitations such as my use of an uncalibrated counter, geometry effects, and the fact that I made no attempt to distinguish between counts due to alpha, beta, or gamma radiation.
The counts were made with a Monitor 5 Geiger counter from S.E. International. Background was very roughly 24 cpm. Count rates at or below 500 cpm were were obtained on the X1 scale of the meter, count rates above 500 cpm but at or below 5000 cpm were obtained on the X10 scale of the meter, and count rates above 5000 cpm were obtained on the X100 scale of the meter. Count rates were made by visually approximating the average meter reading.