The measurement accuracy of residual oxygen meters is affected by various factors. Sensor performance is a key factor, as different types of sensors have different accuracies, and sensor aging and contamination can reduce measurement accuracy. In terms of environmental factors, changes in temperature, humidity, and pressure can affect the state of gases and the performance of sensors. For example, excessively high or low temperatures can alter the chemical reaction rate of electrochemical sensors, leading to measurement deviations; High humidity may cause sensors to become damp, affecting measurement accuracy. The gas flow rate can also affect the measurement results. Unstable or non compliant flow rates can lead to insufficient or excessive gas response within the sensor, resulting in measurement errors. In addition, the calibration status of the instrument, the length and material of the sampling pipeline, etc. can also affect the measurement accuracy. If the sampling pipeline is too long or the material has strong adsorption, it may cause changes in the gas composition, thereby affecting the measurement results.