METHOD FOR DETERMINING CONCENTRATION LIMITS OF BENZENE VAPOR WITH AIR INFLAMMATION Russian patent published in 2008 - IPC G01N27/12 

FIELD: chemistry.

SUBSTANCE: lower concentration limit of the inflammation of benzene vapor with air is determined, for this purpose, the electrodes of the piezoelectric quartz resonator of AT section with oscillation frequency 9 MHz are modified by applying on them by static evaporation, the drop of fullerene C₆₀ solution; the tested air is blown off with compressor through the detection cell, preliminary, it is passed through the filtrating cartridge containing stripping powder to capture the unsaturated aromatic hydrocarbons, and the grained calcium chloride to capture the water steam; the compressor is switched off, and the input and output nipples of the detection cell are closed with plugs; a sensor is placed into the detector and connected to the high-frequency generator; the analytic signal is recorded as oscillation frequency of the resonator quartz plate when the thermodynamic equilibrium is achieved in the sorptive system which is determined by constancy of the resonator's oscillation frequency in time, the lower concentration limit of the inflammation of benzene vapor with air is found. To determine the upper concentration limit of the inflammation of benzene vapor with air, the apiezone-N modified sensor is used. The technique of determination is the same as in determination of the lower concentration limit of the inflammation of benzene vapor with air.

EFFECT: method provides simple testing, doesn't require preliminary sample preparation, and allows determining concentration limits of inflammation of benzene vapor with air in real time mode and timely detecting highly explosive situation.

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