The CFC-11 scale was updated in 2016. An update was needed because existing primary standards dated to 1992 and some were showing signs of contamination. The following equation can be used to convert from the X1993 scale to the current X2016 scale.
Where: Y=value on X2016, and X=value on X1993 (pmol/mol, or ppt)
| CFC-11 calibration standards | X2016 scale | |||
|---|---|---|---|---|
| updated: July, 2016 | ||||
| year | prepared ppt | assigned ppt | residual ppt | |
| SX3585 | 2015 | 230.15 | 230.13 | -0.02 |
| SX3586 | 2015 | 258.93 | 259.07 | 0.14 |
| ALMX067946 | 2016 | 171.27 | 171.33 | 0.06 |
| ALM067687 | 2015 | 201.61 | 201.56 | -0.05 |
| ALM026729 | 2016 | 100.84 | 100.82 | -0.02 |
