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1. (WO2018178036) METHOD FOR DETERMINING THE PARTIAL PRESSURE OR A CONCENTRATION OF A VAPOUR

Pub. No.:    WO/2018/178036    International Application No.:    PCT/EP2018/057700
Publication Date: Fri Oct 05 01:59:59 CEST 2018 International Filing Date: Wed Mar 28 01:59:59 CEST 2018
IPC: C23C 14/04
C23C 14/54
G01N 29/036
Applicants: AIXTRON SE
Inventors: LONG, Michael
BECCARD, Birgit Irmgard
CREMER, Claudia
Title: METHOD FOR DETERMINING THE PARTIAL PRESSURE OR A CONCENTRATION OF A VAPOUR
Abstract:
The invention relates to a method for determining the partial pressure or concentration of a vapour in a volume (2), a sensor surface (6) of a sensor body (5) oscillating with an oscillation frequency being kept at a temperature at which the vapour condenses on the sensor surface (6), forming a constantly growing mass accumulation that affects the oscillation frequency. In order to increase the service life, according to the invention, the temperature is chosen such that when a limit partial pressure or a limit concentration of the vapour in the volume (2) is not reached, the mass accumulation decreases. The mass change increases for the period (t1) of a process step, in which the vapour flows through the transport conduit (1) or is present in the volume (2), and decreases to zero in a process pause (t2) between two process steps, in which pause no vapour flows through the transport conduit (1) or is present in the volume (2).