| 摘要 |
FIELD: measuring equipment.SUBSTANCE: method of monitoring changes integral composition gas relates to electrical measurements and can be used in analytical-measuring complexes for continuous monitoring of parameters of atmosphere in closed spaces in mines and tunnels, as well as in automatic control systems of technological processes, systems of continuous environmental monitoring and meteorology. Properties of invention is especially important for use in coal mines, on plants with toxic and harmful environment, as well as on inflammable and explosive production works, where gases, dust and vapors are non-uniformly distributed in volume of working space. Novel in method of monitoring changes integral gas medium is using only microwave communication channel for phase measurements and synchronisation of high-frequency high-Q quartz reference generators in order to reduce costs for design and production of equipment and optimising of radio channel. During controlling changes in integral gas medium microwave signal, modulated by amplitude of low-frequency clock signal is emitted into measuring channel. Then microwave signal is received by relay and amplified, then low-frequency clock signal is separated from it, which is used to synchronise local reference generator using automatic phase frequency control system. Then monotonously rising phase shift in microwave controlled phase shifter is introduced into microwave signal, after which microwave signal is emitted back. From received microwave signal, after homodyne frequency conversion low-frequency information component is selected. By phase difference measured between low-frequency reference and information signals, change of relative permittivity of medium is determined, and hence integral gas medium composition.EFFECT: advantage of this method consists in protection of sensors against dust, moisture, vapors, low measurement time and possibility of monitoring changes integral gas medium on long routes and in large volumes of working spaces.1 cl |
