The invention relates to an ionization vacuum measuring cell (10) comprising an evacuable housing (12) with a measurement connection for a vacuum to be measured at an end portion; a measurement chamber (14) in the housing (12), said measurement chamber being fluidically connected to the measurement connection, wherein the measurement chamber (14) is designed as a replaceable component; and a first and a second electrode (16, 18) in the measurement chamber (14), said electrodes being substantially coaxial to an axis and being arranged at a distance from each other. The measuring cell further comprises an electrically insulating and vacuum-tight feedthrough (20) for an electric supply to the second electrode (18) and a magnetization assembly which is designed to generate a magnetic field in the ionization chamber. According to the invention, the measurement chamber (14), in particular at least one of the electrodes (16, 18), comprises a magnetic material.

The disclosure provides a gas detector with an ionizing device for producing ions depending on a gas to be detected. The gas detector includes a catcher for receiving the electrical current produced by the ions, and a measuring device with an electrical measuring resistor. The electrical measuring resistor produces an electrical measuring potential from the current and is surrounded, at least in part, by an electrical shield resistor, denoted by R.sub.T. The same potentials, up to a deviation of at most 25%, are applied in the longitudinal direction of the electrical measuring resistor to mutually opposed regions of the electrical measuring resistor and the electrical shield resistor.

In a described example, an apparatus includes: at least one electrode having a base on a first surface of a substrate and extending away from the base to an end; a counter-electrode spaced from the end of the at least one electrode, having a first conductive surface facing the end; and a package having a cavity containing the at least one electrode, the substrate, and the counter-electrode, the package having at least one opening configured to allow an atmosphere to enter the cavity.

In a described example, an apparatus includes: at least one electrode having a base on a first surface of a substrate and extending away from the base to an end; a counter-electrode spaced from the end of the at least one electrode, having a first conductive surface facing the end; and a package having a cavity containing the at least one electrode, the substrate, and the counter-electrode, the package having at least one opening configured to allow an atmosphere to enter the cavity.

A light source emits excitation light to discharge gas that flows through a dielectric tube. A ground electrode unit includes a first ground electrode and a second ground electrode arranged at a distance from each other in an axial direction of the dielectric tube. A high-voltage electrode is provided between the first ground electrode and the second ground electrode. A first distance between the first ground electrode and the high-voltage electrode is shorter than a second distance between the second ground electrode and the high-voltage electrode. A cover is provided on an outer wall of the dielectric tube at a position between the first ground electrode and the high-voltage electrode. The light source is arranged to emit excitation light such that an optical axis thereof is directed toward a position where the cover is not provided on the outer wall of the dielectric tube.

A light source emits excitation light to discharge gas that flows through a dielectric tube. A ground electrode unit includes a first ground electrode and a second ground electrode arranged at a distance from each other in an axial direction of the dielectric tube. A high-voltage electrode is provided between the first ground electrode and the second ground electrode. A first distance between the first ground electrode and the high-voltage electrode is shorter than a second distance between the second ground electrode and the high-voltage electrode. A cover is provided on an outer wall of the dielectric tube at a position between the first ground electrode and the high-voltage electrode. The light source is arranged to emit excitation light such that an optical axis thereof is directed toward a position where the cover is not provided on the outer wall of the dielectric tube.

A degree of similarity in the peak pattern between a mass spectrum obtained for an unknown target substance in a sample and a mass spectrum of a known specific substance is calculated (S4). If the degree of similarity is within a range of 80-60% (“No” in S6), the ratio between the signal intensities at two mass-to-charge ratios characteristic of the specific substance is calculated and compared with a reference value (S7 and S8). If the intensity ratio exceeds the reference value, the target substance is likely to be the specific substance. Therefore, as in the case where the degree of similarity is equal to or higher than 80%, it is concluded that the specific substance is contained in the sample (S10). In advance of such a judgment, whether or not the sample has been certainly subjected to the mass spectrometric analysis is determined from a graph of the total ion current signal created from data collected by performing a measurement from a point in time before the sample is placed at a measurement position (S2 and S3). If no significant peak is present in the graph, it is concluded that a sample introduction error has occurred (S11). By such a method, a higher level of qualitative determination accuracy can be achieved than in a conventional qualitative analysis using only the degree of similarity.

A degree of similarity in the peak pattern between a mass spectrum obtained for an unknown target substance in a sample and a mass spectrum of a known specific substance is calculated (S4). If the degree of similarity is within a range of 80-60% (“No” in S6), the ratio between the signal intensities at two mass-to-charge ratios characteristic of the specific substance is calculated and compared with a reference value (S7 and S8). If the intensity ratio exceeds the reference value, the target substance is likely to be the specific substance. Therefore, as in the case where the degree of similarity is equal to or higher than 80%, it is concluded that the specific substance is contained in the sample (S10). In advance of such a judgment, whether or not the sample has been certainly subjected to the mass spectrometric analysis is determined from a graph of the total ion current signal created from data collected by performing a measurement from a point in time before the sample is placed at a measurement position (S2 and S3). If no significant peak is present in the graph, it is concluded that a sample introduction error has occurred (S11). By such a method, a higher level of qualitative determination accuracy can be achieved than in a conventional qualitative analysis using only the degree of similarity.

Pulsed Field Magnetometry (PFM) method and apparatus to compensate for zero signal errors in a material characterisation process involving first constructing a synthesised zero signal expressed with a range of variable parameters. A measurement cycle is performed on a sample of material to be characterised the waveform data obtained in said measurement cycle is stored. The synthesised zero signal is then applied to the stored data while adjusting the values of the variable parameters, and the values are selected which best fit the synthesised zero signal to the stored data. The synthesised zero signal with the selected values is then removed from the stored data to obtain compensated material characterisation data.

Embodiments relate generally to an ultraviolet lamp (100) for use with a photoionization detector comprising a sealed tube (102) configured to contain at least one gas; a coating (120) applied to the inner surface (110) of the sealed tube (102); and a crystal window (112) attached to the sealed tube (102), configured to allow transmittance of ultraviolet (UV) light generated within the sealed tube (102). Additional embodiments include a method of forming an ultraviolet lamp (100) for use with a photoionization detector, the method comprising applying at least one layer of a coating (120) onto an inner surface (110) of a sealed tube (102); sealing a crystal window (112) onto the sealed tube (102); filling the sealed tube (102) with at least one gas; sealing the sealed tube (102) containing the at least one gas; generating ultraviolet radiation using the at least one gas within the sealed tube (102); and directing the generated ultraviolet radiation through the crystal window (112) toward a sample gas in the photoionization detector.