Teledyne 3290 - OEM percent oxygen analyzer - Manual (Page 44)

Maintenance Model 3290
Teledyne Analytical Instruments 34
If a cell was working satisfactorily, but ceases to function before
the warranty period expires, the customer will receive credit toward the
purchase of a new cell.
With any warranty claim, the customer must return the cell in
question to the factory for evaluation. If it is determined that failure is
due to faulty workmanship or material, the cell will be replaced at no
cost to the customer.
Note: Evidence of damage due to tampering or mishandling will
render the cell warranty null and void.