Disdrometer is a laser based optical device for simultaneous measurement of PARticle SIze and VELocity of all liquid and solid precipitation. The patented extinction method for simultaneous measurements of particle size and velocity of all liquid and solid precipitation performs the direct physical measuring principle and classification of hydrometeors. The instrument provides a full picture of the precipitation event in all weather phenomena and provides accurate reporting of precipitation types and intensities without degradation of performance in severe outdoor environments. Parsivel ® operates in any climate weather regime and the incorporated heating device minimizes the negative effect of freezing and frozen precipitation accreting critical surfaces on the instrument.