Devices and corresponding methods can be provided to test an ionization gauge, such as a hot cathode ionization gauge, for leakage currents and to respond to the leakage currents to improve pressure measurement accuracy. Responding to the leakage current can include applying a correction to a pressure measurement signal generated by the gauge based on the leakage current. Responding to the leakage current can also include removing contamination causing the leakage current, where the contamination is on electrical feedthrough insulators or other gauge surfaces. Testing and correcting for leakage currents and removing contamination can be completed with the ionization pressure gauge in situ in its environment of use, and while the gauge remains under vacuum.

Provided are: a vacuum gauge that, with a simple configuration, can accurately diagnose the degree of contamination of the vacuum gauge; and a contamination diagnosis method that, with a simple process, can accurately diagnose the degree of contamination of a vacuum gauge. Provided is a cold cathode ionization vacuum gauge that has a normal operation mode and a contamination diagnosis mode, the cold cathode ionization vacuum gauge comprising: an anode 1 and a cathode 3 that are for measuring vacuum pressure in the normal operation mode; an anode 7 and the cathode 3 that are for measuring the vacuum pressure in the contamination diagnosis mode; and a controller 10 that compares the size of a current measured between the anode 7 and the cathode 3 and the size of a current measured between the anode 1 and the cathode 3.

A vacuum feedthrough (10) which is constructed in radial layers comprises the following elements (from inwards to outwards): a lens element (11), a first ring (12) made of glass, a first hollow cylinder (13) made of a first dielectric material, a first electrically conductive layer (18), a second hollow cylinder (14) made of glass, a third hollow cylinder (15) made of ceramic, a second ring made of glass (16), anda frame (17) made of metal. On the basis of the vacuum feedthrough, the invention additionally relates to an electrode assembly, to a device for generating a DBD plasma discharge, to a measuring device for characterizing a pressure and/or a gas composition, and to a method for operating the measuring device.

The invention relates to a 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 which is fluid-dynamically connected to the vacuum system and which is in electrical contact with a first electrode and a second electrode; b) measuring 102 a current intensity of an electrical current flowing through the plasma between the first electrode and the second electrode; c) measuring 103 a first radiation intensity 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 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 is outside the first wavelength range; and e) determining 105 the pressure in the vacuum system as a function of the measured current intensity, the measured first radiation intensity, and the measured second radiation intensity. Further, the invention relates to a vacuum pressure sensor.

An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

Devices and corresponding methods are provided to operate a hot cathode ionization pressure gauge (HCIG). A transistor circuit can be configured to pass the electron emission current with low input impedance and to control cathode bias voltage. Emission current and cathode bias voltage can be controlled independently of each other, without a servo settling time. HCIGs can be calibrated with respect to leakage current.

Devices and corresponding methods are provided to operate a hot cathode ionization pressure gauge (HCIG). A transistor circuit can be configured to pass the electron emission current with low input impedance and to control cathode bias voltage. Emission current and cathode bias voltage can be controlled independently of each other, without a servo settling time. HCIGs can be calibrated with respect to leakage current.

A thermionic sensor is disclosed. The sensor includes a sensor housing at least partially defining an emission chamber in which at least a partial vacuum is maintained; a cathode disposed in the emission chamber; an anode disposed in the emission chamber and spaced apart from the cathode; and an electrically conductive layer disposed in the emission chamber facing the anode and cathode. The thermionic sensor is configured to output a detection signal when the anode and cathode are at substantially the same temperature.

A thermionic sensor is disclosed. The sensor includes a sensor housing at least partially defining an emission chamber in which at least a partial vacuum is maintained; a cathode disposed in the emission chamber; an anode disposed in the emission chamber and spaced apart from the cathode; and an electrically conductive layer disposed in the emission chamber facing the anode and cathode. The thermionic sensor is configured to output a detection signal when the anode and cathode are at substantially the same temperature.