Teledyne 3010TB Operating Instructions Manual page 80

4 Operation Model 3010TB
c. Check whether more time is needed for PPM readings to drop to
an acceptable level. This is true when coming down from high
level.
If there are no leaks and the span gas is OK, replace the cell as de-
scribed in Part II: Analysis Units chapter 5, Maintenance.
4-4: Part II
Teledyne Analytical Instruments