Ametek Thermox WDG-1200 Insitu, Руководство пользователя

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5-8 | Thermox WDG-1200/1210 Insitu Probes
in-situ Probe testing and checking
In-situ checking will assist with identifying errors or faults associated with the probe.
Cell output voltage can be displayed on the user interface using the
Diagnostics
menu as an alternative to the following manual checks. After any corrections the
system must be fully calibrated.
Equipment required:
• Digital multimeter (10M Ω input impedance on mV ranges).
• Earth continuity tester.
• Span calibration gas (within the range 10 to 21% O
2
in N
2
).
• Zero calibration gas (within the range 0.1 to 10% O
2
in N
2
).
Ensure that the flue temperature is within the limits 20 °C / 68 °F to 600 °C / 1112
°F and allow a 20-minute warm-up period for the probe.
1. Remove the blanking plug from the calibration gas inlet and fit the pipe, nut
and olive from the connector kit to the inlet.
2. Connect the calibration gas using flexible tubing to fit the outside diameter of
the pipe ( ¼” o.d.).
3. Apply the test gas at a rate of 2 l/min (4.5 ft
3
/hour) and allow 5 minutes for the
analyzer reading to settle.
If the analyzer response is normal when measuring calibration gas, but sluggish and
insensitive when measuring flue gas, replace the ceramic filter.
If you cannot obtain the correct calibration gas response, measure the cell output
voltage detailed in the Step 4.
4. With the calibration gas connected, display the EMF of the cell by selecting
CELL from the Diagnostics menu.
The measured voltage should correspond generally to the oxygen volume per-
centage for the calibration gas used. Slight differences result if the probe’s cell
constant is not zero.
If there is a difference of more than ±5mV between the measured cell output voltage
and the graph, check the probe heater temperature by measuring the thermocouple
voltage as described in the following Steps 5 and 6.
5. Using either a mercury or digital-type thermometer, measure the ambient
temperature in close proximity to the Probe T/C connections at the head of the
probe.