apparatus for metning of particle size and mengden in a liquid medium

摘要

An apparatus for the measurement of particle size and quantity in a fluid, especially air, contains a light- sensitive arrangement 4. The fluid is made to flow through a light beam emanating from a light source 2. The light which is then scattered by particles in the fluid flow, and a portion of the light in the beam that is supplied from a calibrated particle-imitating element 6, is converted by the light-sensitive arrangement into electric pulses. A pulse distributor 12 distributes these pulses according to particle size and is connected to signal inputs of threshold arrangements 11 corresponding to different particle sizes, whose outputs are connected to the inputs of one indicating counter 16 for each of them. The element 6 imitating a calibrated particle is arranged to periodically vary the light intensity for the light received by the light-sensitive arrangement while a measurement is taking place. Between the light-sensitive arrangement's output and the reference inputs of the threshold arrangements is connected a converter 10 for converting the output pulses of the light-sensitive arrangement into a D.C. voltage, which regulates the threshold levels of the threshold arrangements as a function of the amplitude of the pulse received from the element imitating a calibrated particle. IMAGE