1) The failure of the trace oxygen analyzer shows that the temperature of the measuring cell is low. You can check the connection of the thermocouple of the measuring cell, check the insurance on the multiplexer board, and check the wiring of the circuit board.
(2) An instrument failure shows that the potential of the measuring cell is high or low. You can check the circuit connection of the measuring cell, check the connection between the circuit boards, and check the zirconia sensor.
(3) The sensor responds slowly to changes in the oxygen content of the sample gas, and the measured value is low. In January 2005, the measurement value of a zirconia trace oxygen analyzer was seriously low, and the sensor response was slow. After checking the sampling system of the instrument, calibrating the zero range, and checking the sensor, it is finally confirmed that the sensor is malfunctioning. After replacing the sensor, the instrument resumes normal measurement.
(4) The instrument calibration failed. The zero point gas and span gas of the instrument should be selected correctly. The zero point gas should be nitrogen with an oxygen content of about 100×10-6, and the span gas should be nitrogen with an oxygen content of 20-95%.
(5) The trace oxygen analyzer drifts greatly. The sample gas pressure is required to be controlled at (34?47±20?68) kPa [(5±3) psi], the flow rate should be controlled at 200~550mL/min, and the instrument should be checked regularly.
(6) The oxygen content in the working environment of the instrument should be the oxygen content of the air, so as to avoid other factors from affecting the oxygen content of the working environment. In June 2005, when the cabinet air conditioner in the analysis room of the company was replaced with freon, the measured value of several zirconia oxygen analyzers fluctuated instantaneously, and the measured value was too high to alarm. After ventilation and displacement analysis of indoor air, the instrument resumes normal measurement.
(7) When the instrument is started up, clean air or nitrogen must be passed into the sampling pipelines and purged clean; the inlet of the instrument should be installed with a filter to avoid damage to the sensor caused by impurities in the sampling pipeline when the air separation equipment is started up.
(8) Ensure that the discharge pipeline of the instrument is unobstructed under normal pressure, and avoid pressure and blockage of the vent pipe, which will affect the measurement accuracy of the instrument.
(9) The flammable gas in the sample gas measured by the trace oxygen analyzer has a certain influence on the measurement result of the zirconia oxygen analyzer, but because the flammable gas content (such as methane, carbon monoxide and carbon dioxide, etc.) is very low, the trace oxygen measurement The interference caused is minimal.
