Teledyne t320u Manual Do Utilizador

Teledyne API – Model T300/T300M CO Analyzer 

EPA Calibration Protocol 

A Level 1 zero and span calibration is a simplified, two-
point analyzer calibration used when analyzer linearity 
does not need to be checked or verified.  (Sometimes 
when no adjustments are made to the analyzer, the 
Level 1 calibration may be called a zero/span check, in 
which case it must not be confused with a Level 2 
zero/span check.)  Since most analyzers have a reliably 
linear or near-linear output response with concentration, 
they can be adequately calibrated with only two 
concentration standards (two-point concentration).  
Furthermore, one of the standards may be zero 
concentration, which is relatively easily obtained and 
need not be certified.  Hence, only one certified 
concentration standard is needed for the two-point (Level 
1) zero and span calibration.  Although lacking the 
advantages of the multipoint calibration, the two-point 
zero and span calibration--because of its simplicity--can 
be (and should be) carried out much more frequently.  
Also, two-point calibrations are easily automated.  
Frequency checks or updating of the calibration 
relationship with a two-point zero and span calibration 
improves the quality of the monitoring data by helping to 
keep the calibration relationship more closely matched to 
any changes (drifts) in the analyzer response. 

A Level 2 zero and span check is an "unofficial" check of 
an analyzer's response.  It may include dynamic checks 
made with uncertified test concentrations, artificial 
stimulation of the analyzer's detector, electronic or other 
types of checks of a portion of the analyzer, etc. 

Level 2 zero and span checks are not to be used as a 
basis for analyzer zero or span adjustments, calibration 
updates, or adjustment of ambient data.  They are 
intended as quick, convenient checks to be used 
between zero and span calibrations to check for possible 
analyzer malfunction or calibration drift.  Whenever a 
Level 2 zero or span check indicates a possible 
calibration problem, a Level 1 zero and span (or 
multipoint) calibration should be carried out before any 
corrective action is taken. 

If a Level 2 zero and span check is to be used in the 
quality control program, a "reference response" for the 
check should be obtained immediately following a zero 
and span (or multipoint) calibration while the analyzer's 
calibration is accurately known.  Subsequent Level 2 
check responses should then be compared to the most 
recent reference response to determine if a change in 
response has occurred.  For automatic Level 2 zero and 
span checks, the first scheduled check following the 
calibration should be used for the reference response.  It 
should be kept in mind that any Level 2 check that 
involves only part of the analyzer's system cannot 
provide information about the portions of the system not 
checked and therefore cannot be used as a verification 
of the overall analyzer calibration. 

A system of Level 1 and Level 2 zero span checks is recommended.  These checks must 
be conducted in accordance with the specific guidance given in Section 12 of the QA 
Handbook Vol II Part 1

1

.  It is recommended that Level 1 zero and span checks be 

conducted every two weeks.  Level 2 checks should be conducted in between the Level 
1 checks at a frequency desired by the user.  Span concentrations for both levels should 
be between 70 and 90% of the measurement range. 

Zero and span data are to be used to: 

1.  Provide data to allow analyzer adjustment for zero and span drift; 
2.  Provide a decision point on when to calibrate the analyzer; 
3.  Provide a decision point on invalidation of monitoring data. 

Items 1 and 2 are described in detail in Subsection 9.1.3 of Section 2.0.9 (Q.A. 
Handbook Vol II

4

).  Item 3 is described in Subsection 9.1.4 of the same section. 

Refer to the Troubleshooting and Repair (see Section 13) of this manual if the 
instrument is not within the allowed variations. 

06864B DCN6314