The HT-DLPI+ (High Temperature Dekati® Low Pressure Impactor) is a 14-stage cascade impactor that is used to determine airborne particle mass size distribution. The HT-DLPI+ can be heated up to 180 °C allowing direct measurement of up to 180 °C aerosol samples without the risk of condensation or sample transformations. The impactor support and heater controller are all integrated into one easy-to-use unit, which also allows control and adjustment of the impactor low pressure and flow rate. The HT-DLPI+ classifies and collects particles into 14 size fractions in the range of 16 nm – 10 μm. In each size fraction, the particles are collected on 25 mm collection substrates that are weighed before and after the measurement to obtain gravimetric size distribution of the particles. A chemical analysis of the size classified particles can also be performed. Since the HT-DLPI+ impactor has the same design as the impactor used in the Dekati® ELPI®+ (Electrical Low Pressure Impactor), it can easily be upgraded into a full ELPI®+ or High Temperature ELPI®+ system for real-time particle size distribution measurements.