International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

A method was developed for contactless evaluation of the number and diameter of droplets in a jet, by means of gravitational separation and measurement of an electrical signal from a laser-induced electromagnetic echo effect (EMEE), at several points of the jet. With it, only with modulated laser radiation, an electrical signal is induced. The measured value of the signal from this EMEE depends on the parameters of the fog (number and sizes of droplets). This signal is measured at several points of the jet, as the droplets must be in laminar flow. After measuring the signal at the first point, the signals at the previous points are subtracted from its value at each subsequent point, in order to separate the measured signal at each point and determine the change in fog parameters. The method represents an affordable and reliable alternative to existing fog characterization techniques.

In this work a new device for measuring the parameters of a fog is described. It is developed by our team and is called Fog Detector Indicator 1 (FDI-1). It is a part of a sensor system for control of the parameters of a fog which is used for decontamination of objects polluted by different circumstances. FDI-1 is a custom indication unit used in various systems for evaluation of fog parameters that gives the operator a visual result for the change of the input voltage. The main function of the indicator is to show the measured voltage applied on its coax input. Usually, this measurement can be done with a regular voltmeter, but the nature of the measurement of a fluid (fog) density, droplet diameter or contamination assumes very rapid changes of the measured values and also very short peaks of the maximum and the minimum of the measured variable. FDI-1 is can be used namely in such cases.