Operational Theory | Model 9060L |
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All Teledyne oxygen probe or sensors are designed and manufactured to exacting standards of performance and reliability and are the result of extensive research and development. Teledyne Analytical Instruments provides worldwide application and after sales support for its oxygen probes, sensors and analyzers.
Figure 2-1: Model 9060L Oxygen Probe
The probe assembly provides a means of exposing the zirconia
sensor to the atmosphere to be measured with sensor. It also provides for means of interfacing the sensor, thermocouple and heater wires with the control unit. Reference air is fed via the top plug for unheated probes or by a separate gas thread connection for heated probes. Connections are provided on probes for an in-situ gas calibration check. If required, an air purge can be admitted via the calibration gas check entry. The outer sheath of probes is either metal or ceramic, depending on the application. Calibration check can be achieved on 9060LEX sensors using a three way solenoid which blocks the sample and at the same time admits a calibration gas to the sensor. As mentioned above, probe purging for removing any dust build up can be achieved in the same way.
In-situ zirconia oxygen probes will give a lower oxygen reading than a sampled gas measurement on a chromatograph or paramagnetic analyzer because the flue gas contains a significant level of water vapor and a sampling system removes the water vapor through condensation. The oxygen content then appears as a higher percentage of the remaining gas. For example: If the gas contained five parts oxygen and fifteen parts moisture, removing the moisture would leave the oxygen at 5.88%. This phenomena will depend on the fuel and the completeness of combustion. They are common to all zirconia oxygen sensors.
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