METHOD FOR DETERMINING CONCENTRATION OF SATURATED VAPOUR OF VOLATILE SUBSTANCES UNDER GIVEN CONDITIONS IN SEALED VOLUME Russian patent published in 2024 - IPC G01N5/04 

FIELD: testing.

SUBSTANCE: invention relates to testing of physical properties of various volatile substances, namely to creation of a method for determining concentration of saturated vapour of volatile substances under specified conditions in a sealed volume. Method of determining concentration of saturated vapour of volatile substances under given conditions in a sealed volume consists in the fact that, first, the volume of analytical balances of the second accuracy class is determined by measuring their geometrical dimensions. Then they are placed in a sealed device with a volume of not less than 0.02 m³ with transparent walls and a hermetically closing transparent cover. Analytical balances of the second accuracy class are switched on and a Petri dish is placed on them. After that, the value of mass with tare is reduced to value of 0 g, and readings of temperature and pressure, which are maintained during the research, are recorded. With a gap in time of not more than 5 seconds, one or more analysed volatile substances, which are in liquid and/or solid states, weighing not less than 10 g, are placed in a Petri dish placed on an analytical balance, the cover of the sealed device is tightly closed and the mass of the analysed volatile substances in the Petri dish is recorded. Change in the mass of the investigated volatile substances in liquid and/or solid states is recorded until the moment when it ceases to change, in particular, to decrease, after which concentration of saturated vapour of one or a mixture of several analysed volatile substances, in particular, liquid and/or solid, under given conditions, in particular temperature and pressure, in a sealed volume is calculated by formula:

where C_sv is concentration of saturated vapour of one or a mixture of several analysed volatile substances, in particular, liquid and/or solid, under given conditions, in particular temperature and pressure, in a sealed volume, g/m³; m₀ is the initial mass of one or a mixture of several analysed volatile substances in liquid and/or solid states, g; m_de is the mass of one or a mixture of several analysed volatile substances, which are in liquid and/or solid states, after the onset of dynamic equilibrium with their saturated vapour, g; V_SD is the volume of the sealed device, m³; V_ab is volume of used analytical balances of the second accuracy class, m³.

EFFECT: possibility of determining concentration of saturated steam of one or more known and (or) unknown volatile substances under specified conditions in a sealed volume.

1 cl, 1 dwg