Calibration
Multipoint Calibration in Dual/Auto Range Mode
Thermo Fisher Scientific
Model 43i Trace Level-Enhanced Instruction Manual
4-7
11.
To enter the calibration gas concentration, use
to move
the cursor left and right. Use
to increment and decrement
the digit. Press
to calibrate the instrument to the SO2 calibration
gas.
The display flashes the message “SAVING”, and the corrected SO2
reading is displayed.
12.
Press the
pushbutton to return to the Run screen. If using a
chart recorder hooked up to an analog output channel, the SO2
recorder response will equal:
Where:
URL
=
upper range limit of the analyzer's operating range
Z
SO2
=
analyzer response to zero air, % fullscale
13.
For multi-point calibration, generate five SO2 concentrations equally
spaced between zero and the concentration above. Record instrument
reading for each concentration after allowing time for both gas
generation system and instrument to stabilize. Plot a graph of
instrument readings against the SO2 concentrations generated. This is
the instrument calibration curve. All future measurements should be
interpreted using this curve.
Regulations typically require multipoint calibration when the instrument is
newly installed, moved, repaired, interrupted for more than a few days, or
when span or zero shift by more than 15%.
All gas must be supplied to the instrument at atmospheric pressure. It may
be necessary to employ an atmospheric bypass plumbing arrangement to
accomplish this.
If a filter is used, all gas must enter the instrument through the filter.
For detailed information about the menu parameters and the icons used in
these procedures, see the “Operation” chapter.
Note
The calibration and calibration check duration times should be long
enough to account for the transition (purge) process when switching from
Z
=
100
x
URL
]
SO
[
SO
OUT
2
2
Multipoint
Calibration in
Dual/Auto Range
Mode
