The oxygen analyzer is designed according to the characteristic that oxygen has high paramagnetism. In the mixed gas, the magnetic susceptibility of oxygen depends almost entirely on the amount of oxygen contained, that is, the amount of oxygen can be determined according to the magnetic susceptibility of the gas.
When using oxygen analyzer, please pay attention to the following points:
- If the air separation unit is shut down for a long time or is stopped for heating, the injection valve of the analytical instrument should be placed in the cut-off position, and the analysis sample gas pipe should be disconnected from the inlet of the analysis cabinet, and the sample gas pressure tube should be Heat and sweep clean together.
2. During measurement, in order to reduce the hysteresis of the measurement, while ensuring the measurement flow of the analytical instrument, the bypass flow of the instrument should be increased as much as possible.
- Zero point calibration of trace oxygen and trace carbon dioxide. At present, the more commonly used method is to add a set of purification devices to remove trace carbon dioxide or trace oxygen and nitrogen in its zero-point sample gas processing system, which is feasible when the complete analysis system is just put into operation. However, as time goes by, each purification device will be in contact with the atmosphere and become invalid, so that the zero point of the calibration instrument is not accurate. Our approach is to learn from the migration principle of the instrument, analyze a bottle of high-purity argon standard gas with an offline analyzer, and measure the O2 content and CO2 content in the high-purity argon as the zero point gas for calibrating the trace oxygen and trace carbon dioxide analyzers. When the instrument is zero, calibrate the zero point of the instrument to the measured value, that is, move the zero point of the instrument to about 0.1∽0.3ppm, and then calibrate the range of the instrument. Practice has proved that this method is feasible.
- The primary battery of the trace oxygen analyzer is a consumable product. When the oxygen content in the sample gas is too high, the inlet and outlet valves of the instrument should be cut off quickly. If the instrument is not used for a long time, consider introducing a higher purity argon gas into the instrument It is used as a protective gas, but it should be noted that the pressure of the protective gas should not be greater than 10KPa, otherwise the back pressure generated is too large and the membrane of the primary battery will be damaged.