SloGlo, Makua13 and JJordon
Thanks for the replies. This is what I thought you guys used. I just looking for confirmation
JJordon: Do you have a Beta correction factor for your RO20 due to your calabration source being a really strong Beta emitter. (According to Eberline the RO20 is 93% efficienct for SR90 but only 30% efficient for Uranium Slab detection.) I believe I know the answer but since I worked there before but I would just like it for the record, so to speak.