CPC G01L 21/34 (2013.01) | 14 Claims |
1. Method (100) for determining a pressure in a vacuum system, wherein the method comprises the steps of:
a) generating (101) a plasma in a sample chamber (20) which is fluid-dynamically connected to the vacuum system and wherein the plasma is in electrical contact with a first electrode and a second electrode;
b) measuring (102) a current intensity (C_plasma) of an electrical current flowing through the plasma between the first electrode and the second electrode;
c) measuring (103) a first radiation intensity (I_1) of electromagnetic radiation of a first wavelength range which is emitted from the plasma, wherein the first wavelength range contains at least a first emission line of a first plasma species of a first chemical element;
d) measuring (104) a second radiation intensity (I_2) of electromagnetic radiation of a second wavelength range, which is emitted from the plasma, wherein the second wavelength range contains a second emission line of the first plasma species of the first chemical element or of a second plasma species of the first chemical element, and wherein the second emission line lies outside the first wavelength range; and
e) determining (105) the pressure (p) in the vacuum system as a function of the measured current intensity (C_plasma), the measured first radiation intensity (I_1) and the measured second radiation intensity (I_2).
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