Patent ID: 7350970

Claim:
A method for dew point measurement, comprising the steps of: providing cooled element having a condensation surface on a dielectric plate; feeding a gas to be studied onto the with a condensation surface to form a condensate film on the condensation surface onto which a light flux is incident; measuring the dew point from a value of reflection of the light flux from the condensation surface, polarizing the incident light flux in a plane of incidence, selecting an angle for the incident light flux so that there is no reflection of the incident light flux in the absence of the condensate film on the condensation surface; measuring a phase difference between the light flux reflected from the condensation surface of the cooled element and from the surface of the condensate film; determining a thickness of the condensate film on the condensation surface of the cooled element; determining a concentration of condensed admixtures in a predetermined volume of the gas on the basis of the value of the thickness of the film formed during a certain period of time.