Clean the workshop and filter tube regularly and use clear water and fine cloth when wiping. If you are testing perspiration fastness standard, you need to clean the external filter tube and inner box every 200 hours to remove the inorganic salt that is attached to the surface. It is recommended to change the air filter (paper net) every 3 months, depending on the filth of the filter. Clean air filter (metal mesh) - check the air filter for dust, sundries. If you are in a dusty environment, you should clean it every two weeks, using a vacuum cleaner, or you can clean it with compressed air or tap water. The irradiance calibration (information prompt M31) is conducted for every 500 hours of the equipment, and the calibration tool is the CR20 irradiance calibration meter; The blackboard (black mark) thermometer is calibrated every six months. It can be done by customers themselves or by professional engineers. Case temperature and humidity sensor probe needs to be replaced...