Abstract: A method of anticipating defects in the operation of a machine, especially a rotary machine in which high-frequency and low-frequency ranges of a body-wave spectrum in a solid part of the machine are detected and respective auto-spectral density functions G.sub.11 and G.sub.22 are formed, the cross spectral density function G.sub.12 being formed from the measurements as well. The magnitude .gamma..sup.2 =G.sub.12.sup.2 /G.sub.11 .multidot.G.sub.22 is formed and the defect is anticipated by an increase in the value of .gamma..sup.2.
Abstract: A method of and an apparatus for measuring the solids content of a hot waste gas wherein the hot waste gas, without cooling, is mixed with a cool gas so that the mixture is at a reduced temperature at which substances in the sample are transformed into the solid state and the sample is cooled without condensation. The gas mixture is then passed through a measuring filter on which the solids are collected. The mixture is preferably formed coaxially.