Piezoelectric droplet generator for the calibration of particle-sizing instruments

Using a piezoceramic tube and a continuous glass capillary, droplets in a d iameter range between 10 mum and 100 mum can be generated. This corresponds to a volume of up to 0.6 pi. The velocity of the generated droplets depend s on droplet size but is constant for each diameter. The liquid can be dose d as single droplet, as an accumulation of droplets or as a chain of drople ts in a frequency range between 1 Hz up to 3 kHz. The lifetime of the dropl ets depends on droplet size and the chemical and physical properties of the dispersed liquid. In addition, for water droplets the humidity of the air near the droplet trajectory influences the lifetime of the droplets.