FIELD: physics.
SUBSTANCE: invention relates to molecular physics, particularly to differential methods of determining diffusion coefficient of water molecules in gases. Differential method of determining diffusion coefficient of water molecules in gases includes measuring current in moisture sensor placed in a vessel with water, at distance (x) from water surface connected to electric circuit with current source and measuring device, is characterized by that current measurement is carried out in a vessel with water, in which two additional sensors are installed, to form a system of three sensors in a one-dimensional diffusion process, wherein one additional sensor is arranged at a distance (x-Δx) from the water surface, other at distance (x+Δx) from water surface, sensors of system are connected in parallel and connected to current source, each sensor is connected to own measuring device, current measurement in each sensor is started to be performed at change of currents in sensors in time, wherein all sensors in the circuit must satisfy the following condition: the current in each of the sensors, if placed at the same distance from the water surface, must be the same, the current in each of the three sensors is measured simultaneously, through experimentally calculated time interval, repeatedly measuring current in sensor, located at distance (x) from water surface, diffusion coefficient is calculated by formula
,
where Δx – distance between sensors; I1(t) is current in sensor arranged at distance (x-Δx) from water surface at time t; I2(t) is current in sensor arranged at distance (x) from water surface at time t; I3(t) is current in sensor arranged at distance (x+Δx) from water surface at time t; I2(t+Δt) is current in sensor arranged at distance (x) from water surface at time moment (t+Δt); Δt is the time interval through which current is measured again in the sensor located at a distance (x) from the water surface.
EFFECT: high accuracy of determining the diffusion coefficient of water molecules in gases.
1 cl, 2 dwg
