Abstract:According to the comparative observing data of more than 20 SL3-1 double tipping rain gauges from two verifications made in the same verification period by Jiangsu Meteorological Instrument Metering and Calibration Station,this paper analyses the self verification data and measuring changes for these sensors in a year.The reasons caused the sensor abnormity are introduced and methods for maintaining and adjusting abnormal sensors are studied.The regularly verification of the rain gauge should be made by the time,which could ensure the accuracy and reliability of measuring data.