The core logic behind the instability of the baseline caused by pressure fluctuations is that chromatographic analysis requires high pressure stability of the carrier gas and auxiliary gas, usually allowing the fluctuation range to be controlled within ± 0.001MPa. When the output pressure of the air generator fluctuates, it can cause uneven airflow velocity, unstable combustion state (such as FID detector) or ionization efficiency fluctuations in the detector, which are reflected in the baseline, manifested as baseline drift, sawtooth noise or sudden fluctuations.

From the perspective of equipment and usage scenarios, the common causes of pressure fluctuations mainly include four categories. One is the malfunction of the air source system, such as the blockage of the intake filter element of the air compressor causing insufficient intake volume, and frequent start stop of the compressor causing pressure fluctuations; The molecular sieve or activated carbon adsorption tower is saturated, which cannot effectively purify the air and causes changes in airflow resistance; The pressure sensor malfunctioned and could not accurately provide feedback on the pressure signal, resulting in misoperation of the control system. The second issue is the connection of pipelines. Aging pipelines, loose joints, or damaged seals can cause air leakage, and the system frequently replenishes pressure to maintain the set pressure; The pipeline is too long, excessively bent, or the pipe diameter is mismatched, resulting in turbulent airflow and uneven pressure loss. The third is the fluctuation of gas load. If the same gas source supplies gas to multiple devices at the same time, the start and stop of other devices will cause instantaneous pressure shock; The internal gas circuit valve of the chromatograph malfunctioned, resulting in a sudden change in gas consumption. The fourth is environmental and maintenance factors, as unstable laboratory voltage affects the operation of compressors and control systems; Long term failure to replace the filter element and discharge condensate water has led to the accumulation of dirt or moisture inside the equipment, affecting the stability of the airflow.

For the above reasons, we can gradually solve them by following the idea of "checking the external first, then repairing the internal". Firstly, conduct a quick investigation by closing the inlet valve of the chromatograph and observing whether the pressure display of the air generator is stable. If it still fluctuates, the problem lies with the generator itself; Check the parts of the pipeline joints, valves, etc. that are prone to air leakage, and apply soapy water to observe the formation of bubbles; Check if there is water accumulation at the condensate discharge outlet of the equipment, and if the filter element is blackened or blocked.

In terms of targeted solutions, if it is a problem with the gas source system, it is necessary to regularly replace the intake filter element and adsorbent material, calibrate or replace malfunctioning pressure sensors, and ensure stable operating voltage of the compressor; For pipeline connection issues, aging pipelines and seals should be replaced, pipeline layout should be optimized, bending and long-distance transmission should be reduced, and pressure regulating valves or buffer tanks should be installed if necessary; If there is a fluctuation in gas load, a separate gas source can be used to supply gas to the chromatograph to avoid multiple devices sharing, and the internal gas circuit valves of the chromatograph should be inspected; In daily maintenance, it is necessary to regularly discharge condensate water, keep the equipment ventilated and dry, and develop replacement cycles for filter elements and adsorbent materials according to usage frequency.

In addition, it is recommended to install precision stabilizing valves and flow meters at the output end of the air generator to monitor pressure changes in real time and provide early warning of fluctuation risks; When installing new equipment, ensure that the pipeline connections are standardized and reserve sufficient maintenance space; The laboratory can establish an equipment operation ledger to record pressure fluctuations and maintenance records, making it easier to trace the root cause of problems.