Thermo Scientific 117080-00, Инструкция по эксплуатации

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Calibration
Pre-Calibration
4-2 48iQ Instruction Manual Thermo Scientific
vapor is not removed, it might be necessary to correct the flow
measurement data when calculating the dilution ratio of the span CO
reference.
A platinum on alumina catalyst, operated at 250 °C, has been found to be a
convenient oxidizer to convert CO to CO
2
.
In order to obtain an accurate dilution ratio in the dilution method used
for calibration, the flow rates must be regulated to 1%, and be measured to
an accuracy of at least 2%. The meter and controller can be two separate
devices, or combined in one device. The user's manual for the meter should
be consulted for calibration information.
Additional information on the calibration of flow devices can be found in
the
Quality Assurance Handbook
1
. It should be noted that all flows should
be corrected to 25 °C and 760 mmHg, and that care should be exercised in
correcting for water vapor content.
Prior to calibration, be sure the instrument is operating properly. Turn on
the instrument and allow it to stabilize for one hour. Select the operating
range and the averaging time of the 48iQ.
●
The averaging time should be less than the zero duration and less than
the span duration.
●
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.
●
If an optional sample line filter is used, the calibration must be
performed through this filter. Ensure that the flow rate into the output
manifold is greater than the total flow required by the analyzer and any
other flow demand connected to the manifold.
External Flow
Meter(s) and
Controller(s)
Pre-Calibration