This listing is for the pictured thoriated glass lens extracted from a pre-1970s Canon camera lens.

 

Size: 21x7mm

 

Thoriated glass may contain up to 30% thorium by weight.

 

Thorium is an ideal source for the Radiacode 101 because it provides the three data points required for calibration at 88, 583 and 2614kEv.

  

For more information regarding measurements between Geiger counters, please search the web for "How Many CPM Should My Sample Read?" quotes included.

 

If the lens has developed a brown tint over time, the discoloration can be mitigated by exposing the lens to ultraviolet light.