Abstract: A method for determining a refractive index in a surface region of an object from a production system which has not cooled to an ambient temperature includes emitting terahertz radiation from a transmitter at an angle of incidence to the surface region of the object. The terahertz radiation is reflected from the surface region of the object and received by a receiver. The refractive index of the surface region of the object from a ratio of the emitted and reflected terahertz radiation is determined using an evaluator in communication with the transmitter and the receiver. The influence of surface properties of the object on a portion of the reflected terahertz radiation is taken into account when determining the refractive index.

Abstract: A method for measuring a tubular strand exiting from an extrusion device comprises directing electromagnetic radiation from an inside of the tubular strand to an inner side of a tubular strand. The electromagnet radiation is radiated from at least one radiation source within a frequency range from 1 GHz to 6000 GHz. The electromagnetic radiation is reflected off of the tubular strand and received by at least one radiation receiver. A value for at least one of a diameter, a wall thickness, and a deviation in shape of the tubular strand is determined from the electromagnetic radiation received by at least one radiation receiver.

Abstract: A device for measuring a strand that is tubular includes a first radiation source to emit terahertz radiation in a first measurement region from an inside onto an inner surface of the strand. A first radiation receiver receives terahertz radiation reflected by the strand in a second measurement region. A first evaluation apparatus determines at least one geometric parameter of the strand in the first measurement region. A second radiation source emits terahertz radiation in the second measurement region from an outside onto an outer surface of the strand. A second radiation receiver receives terahertz radiation reflected by the strand in the second measurement region. A second evaluation apparatus determines at least one geometric parameter of the strand in the second measurement region. A third evaluation apparatus determines a change in the at least one geometric parameter of the strand between the first and second measurement regions.

Abstract: A method is provided for detecting a defect of a strand-like product conveyed in a conveying direction at a conveying speed of more than 50 m/min. The method includes determining a frequency of a lateral movement of the strand-like product. The lateral movement occurs in a direction that is transverse to the conveying direction. Terahertz radiation is emitted at a wavelength by at least one transmitter onto the strand-like product conveyed in the conveying direction. The terahertz radiation is reflected by the strand-like product and received by at least one receiver. A temporary change in the terahertz radiation received by the at least one receiver is detected. A defect in the strand-like product is inferred when the temporary change in the terahertz radiation received by the at least one receiver is higher than the frequency of the lateral movement of the strand-like product.

Abstract: A device for determining at least one of a speed and a length of a product. The device includes a laser for irradiating a surface of the product, a detector apparatus to detect laser radiation backscattered from the surface, a first sensor with a first transmission grid arranged in front of the first sensor and a second sensor. A first beam splitter splits laser radiation backscattered from the product into laser radiation conducted to at least one of the first sensor and to the second sensor. An evaluation apparatus determines at least one of: (i) the speed; and (ii) the length of the product. A third sensor is provided as is a second beam splitter that splits laser radiation coming from the first beam splitter to at least one of the sensors. The evaluation apparatus eliminates a direct component of the measurement signal received by the first sensor.

Abstract: A device for measuring a strand that is tubular includes a first radiation source to emit terahertz radiation in a first measurement region from an inside onto an inner surface of the strand. A first radiation receiver receives terahertz radiation reflected by the strand in a second measurement region. A first evaluation apparatus determines at least one geometric parameter of the strand in the first measurement region. A second radiation source emits terahertz radiation in the second measurement region from an outside onto an outer surface of the strand. A second radiation receiver receives terahertz radiation reflected by the strand in the second measurement region. A second evaluation apparatus determines at least one geometric parameter of the strand in the second measurement region. A third evaluation apparatus determines a change in the at least one geometric parameter of the strand between the first and second measurement regions.

Abstract: The invention relates to a method for measuring a tubular strand exiting from an extrusion device, wherein electromagnetic radiation is directed from at least one radiation source within a frequency range of 1 GHz to 6000 GHz from the inside to the inner side of the tubular strand, wherein electromagnetic radiation reflected by the tubular strand is received by at least one radiation receiver, and wherein the diameter, and/or the wall thickness, and/or deviations in shape of the tubular strand are ascertained from the received electromagnetic radiation. Moreover, the invention relates to a corresponding device.

Abstract: Mass spectrometers ionize samples by matrix-assisted laser desorption (MALDI). The samples are located on a moveable support plate, and irradiated by a pulsed laser. A fast positional control of laser spots is provided via a system of rotatable mirrors to relieve strain on a support plate motion drive. If the spot position is finely adjusted by the mirror system and follows the movement of the sample support plate, the intermittent movement of the sample support can be replaced with a continuous uniform motion. The fast positional control allows more uniform ablation of a sample area. Galvo mirrors with low inertia may be used between the beam generation and a Kepler telescope in the housing of the laser. The positional control can also provide a fully automatic adjustment of MALDI time-of-flight mass spectrometers, at least if the ion-optical elements are equipped with movement devices.

Abstract: The amplification of secondary-electron multipliers in mass spectrometers is automatically adjusted by generating mass spectra with single ion signals, determining the average value of the peak heights of these single ion signals, and setting the amplification so that the average peak height assumes a desired nominal value. The amplification may be set via the supply voltage of the secondary-electron multiplier and can be increased or decreased by a desired factor using the known characteristic of the secondary-electron multiplier.

Abstract: Mass spectrometers ionize samples by matrix-assisted laser desorption (MALDI). The samples are located on a moveable support plate, and irradiated by a pulsed laser. A fast positional control of laser spots is provided via a system of rotatable mirrors to relieve strain on a support plate motion drive. If the spot position is finely adjusted by the mirror system and follows the movement of the sample support plate, the intermittent movement of the sample support can be replaced with a continuous uniform motion. The fast positional control allows more uniform ablation of a sample area. Galvo mirrors with low inertia may be used between the beam generation and a Kepler telescope in the housing of the laser. The positional control can also provide a fully automatic adjustment of MALDI time-of-flight mass spectrometers, at least if the ion-optical elements are equipped with movement devices.

Abstract: The invention relates to the measurement of daughter ion spectra of analyte substances that are ionized by means of matrix-assisted laser desorption. The invention shows how to record several daughter ion spectra from several parent ions per single pulse of laser light, that is per desorption event, by spatially splitting the ion beams or by temporally sequencing the spectral measurement; the various parent ions are selected one after another by switching the parent ion selector several times. Summing up corresponding individual daughter ion spectra from many pulses of laser light leads to several sum spectra being recorded practically synchronously with the same series of laser light pulses, with correspondingly reduced sample consumption and shortened data acquisition time.

Abstract: The invention relates to spatially resolved mass spectrometric measurement and visualization of the distribution of small molecules in a mass range from approximately 150 to 500 Daltons, for example drugs and their metabolites, in thin sections or other two-dimensional samples, preferably with ionization of the molecules by matrix-assisted laser desorption. The invention includes the steps measuring a daughter ion produced by forced decomposition of the molecular ion instead of the ionized analyte molecule itself, the daughter ion having a much better signal-to-noise ratio. The daughter ions are detected in a relatively simple reflector time-of-flight mass spectrometer instead of using an expensive time-of-flight tandem mass spectrometers for the measurement of the daughter ions.

Abstract: In a mass spectrometer having an ion source in which analyte substances are ionized by matrix assisted laser desorption and form an ion beam that travels to a parent ion selector for selecting ions to form daughter ions, the ion beam is reflected in at least one reflector prior to the parent ion selector so that only ions that have both the mass of the parent ions and their kinetic energy are allowed to pass to the parent ion selector. By taking this measure, the mass resolution in the daughter ion spectra is also increased; the improved mass resolution and improved signal-to-noise ratio produce higher sensitivity, even though fewer ions are admitted for analysis in the daughter ion spectrum.

Abstract: In an ion source that generates ions by matrix-assisted laser desorption (MALDI), ion acceleration diaphragms having apertures though which ions are accelerated and which have become contaminated by matrix material, are cleaned by temporarily heating the diaphragms. During the cleaning process, the sample support plate is moved aside but remains in the ion source housing, and the heating is preferably limited to regions surrounding the apertures in the diaphragms. In one embodiment, the diaphragms are heated by irradiation generated by infrared laser diodes.

Abstract: The amplification of secondary-electron multipliers in mass spectrometers is automatically adjusted by generating mass spectra with single ion signals, determining the average value of the peak heights of these single ion signals, and setting the amplification so that the average peak height assumes a desired nominal value. The amplification may be set via the supply voltage of the secondary-electron multiplier and can be increased or decreased by a desired factor using the known characteristic of the secondary-electron multiplier.

Abstract: In an ion source that generates ions by matrix-assisted laser desorption (MALDI), ion acceleration diaphragms having apertures though which ions are accelerated and which have become contaminated by matrix material, are cleaned by temporarily heating the diaphragms. During the cleaning process, the sample support plate is moved aside but remains in the ion source housing, and the heating is preferably limited to regions surrounding the apertures in the diaphragms. In one embodiment, the diaphragms are heated by irradiation generated by infrared laser diodes.

Abstract: The invention relates to the automatic cleaning of ion sources inside mass spectrometers, especially the cleaning of ion sources where the ions are generated by matrix-assisted laser desorption (MALDI). The invention consists in cleaning the electrodes of the ion source, which are contaminated with organic material, in the mass spectrometer itself by etching with reactive ions produced by an electrically generated gas discharge in a specially admitted reactant gas.

Abstract: The invention relates to the measurement of daughter ion spectra of analyte substances that are ionized by means of matrix-assisted laser desorption. The invention shows how to record several daughter ion spectra from several parent ions per single pulse of laser light, that is per desorption event, by spatially splitting the ion beams or by temporally sequencing the spectral measurement; the various parent ions are selected one after another by switching the parent ion selector several times. Summing up corresponding individual daughter ion spectra from many pulses of laser light leads to several sum spectra being recorded practically synchronously with the same series of laser light pulses, with correspondingly reduced sample consumption and shortened data acquisition time.

Abstract: In a mass spectrometer having an ion source in which analyte substances are ionized by matrix assisted laser desorption and form an ion beam that travels to a parent ion selector for selecting ions to form daughter ions, the ion beam is reflected in at least one reflector prior to the parent ion selector so that only ions that have both the mass of the parent ions and their kinetic energy are allowed to pass to the parent ion selector. By taking this measure, the mass resolution in the daughter ion spectra is also increased; the improved mass resolution and improved signal-to-noise ratio produce higher sensitivity, even though fewer ions are admitted for analysis in the daughter ion spectrum.

Abstract: The invention relates to spatially resolved mass spectrometric measurement and visualization of the distribution of small molecules in a mass range from approximately 150 to 500 Daltons, for example drugs and their metabolites, in thin sections or other two-dimensional samples, preferably with ionization of the molecules by matrix-assisted laser desorption. The invention includes the steps measuring a daughter ion produced by forced decomposition of the molecular ion instead of the ionized analyte molecule itself, the daughter ion having a much better signal-to-noise ratio. The daughter ions are detected in a relatively simple reflector time-of-flight mass spectrometer instead of using an expensive time-of-flight tandem mass spectrometers for the measurement of the daughter ions.