Single Point Internal Calibration - Thermo Scientific 48i Instruction Manual

Single Point Internal
Calibration
Span Adjust
Thermo Fisher Scientific
The calibration and calibration check duration times should be long
enough to account for the transition (purge) process when switching from
sample to zero and from zero to span. This transition time is the time
required to purge the existing air.
Depending on the plumbing configuration and the instrument, data from
approximately the first minute of a zero calibration or check should be
disregarded because of residual sample air. Also, data from approximately
the first minute of a span calibration or check should be disregarded
because the span is mixing with the residual zero air.
See the following procedures for a single point internal calibration.
Zero Adjust
Use the following procedure to set the CO reading to zero.
1. Allow the analyzer to sample ambient air for at least 5 minutes, or until
a stable reading is obtained.
2. Press
3. Allow the instrument to run with the zero scrubber activated for at least
5 minutes, or until a stable signal is observed.
4. In the CO Background screen, press
zero.
Use the following procedure to adjust the span.
1. If necessary, open the main cylinder valve on the CO span gas and
adjust the output pressure to 10 ± 2 psi.
2. Press
The display shows the current CO concentration reading. The next line
of the display shows the CO concentration of the span gas cylinder.
3. If you have not already done so, verify that excess span gas is flowing
out the "Span Out" bulkhead at 250 to 750 cc per minute.
▲
and choose Calibration > Cal Background.
and choose Calibration > Cal Coefficient.
Model 48i Trace Level-Enhanced Instruction Manual
Calibration
▲
to set the CO reading to
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