Hello Tim: I shall be very grateful if you can review the following calculation for me. It is based on the input received from you 3.2 pCi/L =1 TU = 2.09E7 atoms/L (Am I right here?? How do you get the atoms/L) Now 3g Tritium = 6.023E23 atoms So 1 atom of Tritium = (3/6.023E23) g So 1TU = (2.09E7*3/6.023E23) g/L = 1.04E-16 g/L Now 1 TU = 0.118 Bq/ L (from Clark & Fritz pp. 175) so 1 TU = 1.04E-16 g/L = 0.118 Bq/L Can we then say that 1.04E-16 g of Tritium = 0.118 Bq ???? Even though Bq is a frequency unit (dps)it appears that it can be equivalenced to mass of tritium. I have to convert TU into a mass unit for a contaminant transport simulation and this is the way I found But is this valid?? I shall be very grateful for your help Regards Bhaskar Joshi : -----Original Message----- From: Timothy P. Rose [mailto:[log in to unmask]] Sent: Tuesday, January 30, 2001 10:21 AM To: [log in to unmask] Subject: [ISOGEOCHEM] errata Bhaskar, You are correct that 1 TU = 3.2 pCi/L, not the other way around. Sorry for the misinformation. I'll go a little slower before I hit the reply button next time. - Tim ***************************************************************** Timothy P. Rose Analytical and Nuclear Chemistry Division, L-231 Lawrence Livermore National Laboratory Livermore, CA 94550 Phone: 925-422-6611 Fax: 925-422-3160 email: [log in to unmask] *****************************************************************