Teledyne 9060 - Zirconium oxide flue gas oxygen analyzer - Manual (Page 23)

9060-Zirconia Analyser
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CAUTION DANGER
Return the ‘BURNER BYPASS’ switch to normal (off) before installing the probe in the flue .
For unheated probes, the probe sensing tip must be raised to at least 650°C
(1200°F) with a portable furnace.
Determine the probe offset in ‘RUN’ mode. Select ‘Sensor EMF’ on the lower line.
With probe in air, stabilised at temperature for 30 minutes, read the ‘Sensor EMF’.
Switch back to ‘set-up’ mode and enter ‘Sensor Offset’ of equal value and the same
polarity.
eg. If the measured ’SENSOR OFFSET’ was -1.2 mV, enter -1.2 mV.
When reading the EMF offset, the flue pressure compensation must be set. If the
probe has been removed from the flue, set the flue pressure compensation set up to
“Fixed” in set-up 34, and the value to 0 in set-up step 38.
2. To set the probe “Low Oxygen Calibration”, replace the air purge in the calibration
check port with a flow of gas from a certified gas bottle. A flow of <1 l/min should be
used. After purging for 1 minute compare the oxygen reading to the oxygen
concentration on the bottle certificate. If the transmitter is reading lower than the
certified level, switch to the ‘set-up’ mode and raise the figure set-up 90 (for sensor
1). An increase of 1% in the set-up entry will increase the oxygen reading by about
3% of the actual oxygen reading.
NOTE: If the set-up items 90 and 91 are not available, see section 5.1.
It is very unusual to need to change the settings by more than 1%. If a setting
of more than 1% seems necessary, check for gas leaks, reference air flow or
excess calibration gas flow.
2.10 AUTO CALIBRATION CHECKING - PROBES
On-line automatic gas calibration check is not normally required. Where it is required
however, the probe can be checked for accuracy in-situ and on-line. Solenoid valves can
admit up to two calibrated gas mixtures into the probe via solenoid valves under
microprocessor control on a timed basis. For details on installation refer Section 3.11. For
details on setting up this facility refer to Set-up steps 57 to 69 in Section 5.5.
During probe auto calibration checking, the transmitter output will freeze and remain
frozen for a further adjustable period, allowing the probe time to recover and continue
reading the flue gas oxygen level.
Calibration check gases may be manually admitted by pressing the ‘CAL’ buttons on
the keyboard while in ‘RUN’ mode. The transmitter output is frozen during the pressing of
these buttons and immediately becomes active when the button is released. If calibration
gas checking is enabled in the Set-up menu for either gas, an automatic gas cycle can be
started by pressing the ‘CAL’ buttons in RUN mode. Pressing any other button can
terminate the cycle.