Abstract:At present,the acid rain stations in China have adopted the latest production of lightning-sensitive PHS-3E PH meter and DDS-307A conductivity meter that used to detect the PH value and K value of conductivity.During the operation,most observers do not understand the principles and lack of experience in routine maintenance and common troubleshooting.By using the acid rain observation equipment of PHS-3E PH meter and DDS-307A conductivity meter with proper routine maintenance and summary of common faults,the observers can use the instrument correctly in acid rain observations,maximize the accuracy of acid rain observation,reduce the number of retests and ensure the normal operation of acid rain observation.