1. Connected heating control Sampling detection type oxygen probe can work normally only after the oxygen sensor is connected with heating control. The output in the cold state is a random signal, which does not mean any significance. After the oxygen sensor is connected to the heating control, it is at room temperature conditions. Both can start normal gas detection. The general probe zero adjustment is at room temperature, after heating the probe, through the measurement of air, with a digital multimeter to measure the probe output millivolt value, this value is the probe zero deviation value, in the display instrument need to add The zero offset corrects the oxygen concentration displayed by the meter.
2. Precautions when installing or replacing an oxygen sensor When installing or replacing an oxygen sensor, correct the oxygen concentration displayed on the oxygen analyzer. Without this work, after replacing the new sensor, the oxygen concentration detected by the oxygen analyzer may deviate from the actual concentration, thereby affecting the measurement.
3. Principle and method of oxygen concentration correction The direct measurement of oxygen sensor output is the measured gas concentration and the standard air differential potential value. We call it the oxygen potential. The value of this potential is different at the zero point (ie, air measurement). There is a deviation in the output potential, and there may be an error in the output potential after the model output converts the oxygen concentration. Therefore, calibration of the probe signal in the oxygen analyzer is a necessary task. Otherwise, the oxygen concentration and the oxygen of the measured gas are displayed. There will be large deviations in concentration, which can not meet the needs of on-site production, or even misdirect the control of production.
The specific correction is generally calibrated by standard gas. The method is to pass the standard gas confirmed and confirmed by standard gas into the probe through the standard gas port, measure the output oxygen potential and the instrument display oxygen concentration. The instrument shows that the oxygen concentration should be the same as the standard gas concentration. Deviation corrects the linear parameters of the instrument. The standard measurement requires the use of at least three standard gas calibration systems with different concentrations, so that after three calibrations, the linearity of the system is corrected and the normal operation of the system is ensured.
4, the impact of dust on the oxygen sensor and purge cleaning method -
Since the oxygen sensor is a long-term on-line measurement device, the dust generated by boilers and other equipment (especially coal burners or powder-fired furnaces, etc.) will clog the air sampling pipeline, causing the measured values ​​to be distorted or even impossible to measure. The dust in the sampling pipe is purged. The length of the purge time is determined by the degree of dust accumulation. This purge method requires the oxygen analyzer to have a corresponding function or a maintenance device that is equipped with an oxygen sensor, if these devices are not available Install Manual Valve Control Compressed air or air pump periodically purges the probe through the purge port, but at this time the following must be observed:
(1) Because the oxygen potential of the oxygen sensor will drop during the purging process, the lowest potential may drop to 1,2 mV. At this time, the detected oxygen potential does not represent the atmosphere in the furnace. This point must be noted;
(2) The flow rate of purge air should be able to remove accumulated dust. During the purge process, the oxygen potential output value of the oxygen sensor can be observed. If the oxygen potential value does not decrease at all times, it indicates that the air flow rate is too small and the dust accumulation is not cleared. Adjust or inspect the purge line. The purge line may have been blocked;
(3) The passage of the purge port is directly connected with the furnace. After each purge, the valve should be closed to block the purge hole to prevent the negative pressure air from entering the furnace and affect the detection of the oxygen sensor.
When analyzing the quality of an oxygen sensor, it should be considered as a separate test component. In detecting the oxygen potential of the oxygen sensor, all the wires connected to the oxygen sensor should be disconnected, and the oxygen potential should be directly detected at the output end of the oxygen sensor with a digital meter of high internal resistance. By detecting the oxygen potential, it is compared with the values ​​in normal use.
2. Precautions when installing or replacing an oxygen sensor When installing or replacing an oxygen sensor, correct the oxygen concentration displayed on the oxygen analyzer. Without this work, after replacing the new sensor, the oxygen concentration detected by the oxygen analyzer may deviate from the actual concentration, thereby affecting the measurement.
3. Principle and method of oxygen concentration correction The direct measurement of oxygen sensor output is the measured gas concentration and the standard air differential potential value. We call it the oxygen potential. The value of this potential is different at the zero point (ie, air measurement). There is a deviation in the output potential, and there may be an error in the output potential after the model output converts the oxygen concentration. Therefore, calibration of the probe signal in the oxygen analyzer is a necessary task. Otherwise, the oxygen concentration and the oxygen of the measured gas are displayed. There will be large deviations in concentration, which can not meet the needs of on-site production, or even misdirect the control of production.
The specific correction is generally calibrated by standard gas. The method is to pass the standard gas confirmed and confirmed by standard gas into the probe through the standard gas port, measure the output oxygen potential and the instrument display oxygen concentration. The instrument shows that the oxygen concentration should be the same as the standard gas concentration. Deviation corrects the linear parameters of the instrument. The standard measurement requires the use of at least three standard gas calibration systems with different concentrations, so that after three calibrations, the linearity of the system is corrected and the normal operation of the system is ensured.
4, the impact of dust on the oxygen sensor and purge cleaning method -
Since the oxygen sensor is a long-term on-line measurement device, the dust generated by boilers and other equipment (especially coal burners or powder-fired furnaces, etc.) will clog the air sampling pipeline, causing the measured values ​​to be distorted or even impossible to measure. The dust in the sampling pipe is purged. The length of the purge time is determined by the degree of dust accumulation. This purge method requires the oxygen analyzer to have a corresponding function or a maintenance device that is equipped with an oxygen sensor, if these devices are not available Install Manual Valve Control Compressed air or air pump periodically purges the probe through the purge port, but at this time the following must be observed:
(1) Because the oxygen potential of the oxygen sensor will drop during the purging process, the lowest potential may drop to 1,2 mV. At this time, the detected oxygen potential does not represent the atmosphere in the furnace. This point must be noted;
(2) The flow rate of purge air should be able to remove accumulated dust. During the purge process, the oxygen potential output value of the oxygen sensor can be observed. If the oxygen potential value does not decrease at all times, it indicates that the air flow rate is too small and the dust accumulation is not cleared. Adjust or inspect the purge line. The purge line may have been blocked;
(3) The passage of the purge port is directly connected with the furnace. After each purge, the valve should be closed to block the purge hole to prevent the negative pressure air from entering the furnace and affect the detection of the oxygen sensor.
When analyzing the quality of an oxygen sensor, it should be considered as a separate test component. In detecting the oxygen potential of the oxygen sensor, all the wires connected to the oxygen sensor should be disconnected, and the oxygen potential should be directly detected at the output end of the oxygen sensor with a digital meter of high internal resistance. By detecting the oxygen potential, it is compared with the values ​​in normal use.
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