Solution：

1. The short-term zero point fluctuation range is less than 1% of the maximum range, which is a normal range. When there is no measured gas concentration, the long-term drift is less than 2% of the maximum range, which is a normal range. If it exceeds this range, it is necessary to confirm whether the on-site environment exists. Gas being measured; if the temperature and humidity in the air fluctuate greatly, it will also cause large fluctuations in values ​​or unstable data.

2. Confirm whether the zero point calibration or target point calibration operation has been performed on the instrument. If the zero point calibration operation is performed in the presence of the measured gas or the target point calibration is performed in the presence of the measured gas, the calibrated concentration value is different from the actual value. The concentration values ​​do not match, which may cause the instrument value to fluctuate greatly or the detected value to be too small. These two situations can be solved by restoring the factory settings.

3. If the problem still cannot be solved, you need to confirm whether high-concentration gas is introduced or high-concentration gas impacts the gas sensor. If the gas sensor is impacted, it means that the value may not be stable after the instrument is turned on and aged for 24 hours. The gas sensor was damaged by impact and needs to be replaced.