EML November 1993 Radon Graph
This Graph shows what we sent EML for the November 18, 1993 Intercomparison Exercise.
A' TESTING COMPANY INC. will report 669 ± 4 Bq/m^3 of Radon as our best estimate of the Radon concentrations in our four, 490 mL soda bottle scintillation cells that where filled by EML at 0730 EST November 15, 1993.
We made four changes since the April 1993 Intercomparison to correct the problems we experienced at that time.
Pressure Correction To determine the pressure correction for these cells, we counted each cell for 10 hours at the 756.0 mm Hg. pressure we received them using the calibration factors we established at 582.0 mm Hg. These values are expressed in pCi/L on the left side of the table below. We then briefly loosened the bottle caps of each cell to release the over pressure and normalize the cell pressure at 588.5 mm Hg. These Radon values are multiplied by 1.28462 to compensate for the Radon loss when the over pressure was released.
- 1.To reduce the leakage, we replaced the bottle caps. It appears as though butyrate thinner deteriorates the plastic gaskets in the caps.
- 2.A small amount of thinner was added to each cell to prevent uneven electrostatic plate out.
- 3.Each cell is now calibrated to it's own separate counter so they all can be counted simultaneously, rather than counting four cells on three counters.
- 4.We made a new filler assembly that will allow the air to pass from one cell to the other with only one vacuum connections at EML.
EML reported 675 Bq/m; Our 669 is 0.99 of the EML Mean.