ISO 9096:2017 describes a reference method for the measurement of particulate matter (dust) concentration in waste gases of concentrations from 20 mg/m3 to 1 000 mg/m3 under standard conditions. ISO 9096:2017 is applicable to the calibration of automated monitoring systems (AMS). If the emission gas contains unstable, reactive or semi-volatile substances, the measurement will depend on the filtration temperature. In-stack methods can be more applicable than out-stack methods for the calibration of automated monitoring systems.