Thermo Scientific TVA2020, Instruction Manual

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Thermo Fisher Scientific TVA2020 Instruction Manual 4-1
Chapter 4
Calibration
This chapter describes procedures for performing a calibration on the
TVA2020. For details, see the following:
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“ Calibration Scenarios ” on page 4-1
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“ Calibration Configuration ” on page 4-3
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“ Detector Counts ” on page 4-9
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“ Defining the Response Factor ” on page 4-10
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“ Flow Calibration ” on page 4-18
The use of multipoint calibration and multiple response factors/curves with
the TVA2020 must be fully understood before employing these features.
To help explain these TVA2020 capabilities, three scenarios follow:
To maximize standard accuracy, it is highly recommended that you
calibrate with methane for the flame ionization detector and isobutylene for
the photoionization detector. Almost all published response factors for
FIDs and PIDs are based upon methane and isobutylene, respectively. By
employing a multipoint calibration for these compounds, you will improve
the accuracy of each detector over the entire dynamic range. Response
factors/curves can then be employed for correcting the detector’s response
to different compounds. However, once a multipoint calibration has been
employed, any response curve must characterize only the relative response
at each concentration, excluding curvature of the calibrated compound.
Thus, use of both multipoint calibration and response curves at the same
time is difficult, and is not recommended.
If, for example, you want to measure several different compounds over
wide concentration ranges, it is best to use a single-point calibration and
then enter response curves for each specific compound (up to 9 response
factors/curves can be entered into the analyzer).
Calibration
Scenarios
Scenario 1
Scenario 2