Abstract: An arrangement for in situ determination of the quantity of turbid matter, aerosol and/or dust in flue gas which flows through a flue by measurement of intensity of light irradiated by means of an optical transmitter in the flue, and dispersed on solid or fluid dispersion particles. The dispersion light is detected by a detector which is arranged outside of the bundle of rays of the transmitter and provided with a wide angle focusing optic. A woodsche horn absorbs the not dispersed part of the bundle of rays of the transmitter. The light source of the transmitter is formed as a xenon spark discharger with intensity maximum in the region of 350-600 nm, the detector signal is evaluated by an evaluating electronic circuit. The arrangement determines extremely low quantities of harmful matter.

Abstract: A ceilometer operating according to a gating method integrates output signals from a light receiver. The output signals are passed by analog gating means during consecutive time slots following each other at the transmitter frequency and being phase shifted relative to transmitted light pulses. The phase shift of the time slots is varied stepwise after preset time intervals. Signals integrated during a time interval are digitalized, processed n a microprocessor and stored in a memory according to height values determined by respective phase shifts of the time slots. The micro-processors forms a smooth function of the signals accordint to height values, differentiates the smooth function, computes maxima and minima, determines maxima differing from a preset threshold value, and selects a maximum which with increasing height value is followed by a minimum.

Abstract: A high-speed photographic device including a spark-discharge flash light unit according to Cranz-Schardin slow-motion camera having an optical projecting and deflecting system for reproducing individual consecutively ignited spark discharges on an image plane is to be adjusted for optimum operation.The device for adjusting the optical system includes a pulse generator connected to ignition control means for the spark gaps and operating at a repetition rate to ignite simultaneously the spark gaps so as to produce a flicker-free test image of all spark discharges on the image plane.