Abstract: Systems and methods using fluid-filled hollow microspheres to assist in monitoring or indicating high-energy blunt impacts on structures such as aircraft. A multiplicity of microspheres may be adhered to or embedded in a coating applied on a surface of a substrate (e.g., a tape or an appliqué), which substrate in turn can be adhered to a surface of a structure to be monitored. The microspheres are designed to rupture at one or more specified pressure thresholds. In some embodiments, the microspheres are filled with electrically conductive fluid which, if released from ruptured microsphere, changes the electromagnetic state of the substrate. In response to the detection of a sufficiently large change in the electromagnetic state of the substrate, a blunt impact indication is generated. The impact site may then undergo non-destructive inspection.

Abstract: The invention relates to a method for producing a magnet unit (1) for a sensor device for detecting a measured variable which characterizes a rotational state of a steering shaft of a motor vehicle, by way of provision of an annular magnet element (3), provision of a sleeve (2) for connecting the magnet unit (1) to a shaft part of the steering shaft, and connection of the magnet element (3) to the sleeve (2), the sleeve (2) being configured with a main body (6) and a multiplicity of tabs (7) which protrude from the main body (6), and the connection comprising the tabs (7) being embedded into respective cut-outs (5) of the magnet element (3) with heating of the magnet element (3).

Abstract: An apparatus for detecting a force effect comprises two electrical conductors which run at a distance from one another, a deformable spacer which is arranged between the two electrical conductors, a first measuring device which is electrically connected to one end of the two electrical conductors in each case and an electrical component which is electrically connected to the respective other end of the two electrical conductors. The first measuring device is designed to detect a change in a variable which can be measured by the measuring device, which change is caused by a change in the distance between the two electrical conductors which is caused by a force effect at at least one place along the two electrical conductors, in order to detect the force effect.

Abstract: A force sensor includes a rigid loaded member including a flat plate having a first major side, a second major side opposite the first major side, and a center; wherein the first major side and the second major side are substantially parallel to each other and to a plane including orthogonal X and Y axes, and are substantially perpendicular to the Z axis; at least two optical strain sensors directly secured to at least one of the first major side and the second major side; and an attachment means secured to the first major side substantially at the center; wherein the loaded member is configured to be securable to an associated supporting surface such that the second major side faces the associated supporting surface.

Abstract: In a fluid pressure sensor with a pressure sensing membrane and an electronic circuit, the electronic circuit is in a section realized so thin that a membrane is formed in this section of the electronic circuit. In the other sections, the electronic circuit is realized thicker than in the section that forms the membrane. This makes it possible to manufacture a particularly compact fluid pressure sensor.

Abstract: The invention provides a micro-electro-mechanical device which includes a substrate, an electrode, and a diaphragm. The electrode includes plural vent holes. The diaphragm is disposed above and in parallel to the electrode, to form a capacitive sensor with the electrode. The diaphragm includes plural ribs protruding upward and/or downward from the diaphragm; the ribs are respectively disposed in correspondence to the plural vent holes and do not overlap nor contact the electrode. A method for making the micro-electro-mechanical device is also provided according to the present invention.

Abstract: The present invention, in one embodiment, provides a method of measuring pressure or temperature using a sensor including a sensor element composed of a plurality of carbon nanotubes. In one example, the resistance of the plurality of carbon nanotubes is measured in response to the application of temperature or pressure. The changes in resistance are then recorded and correlated to temperature or pressure. In one embodiment, the present invention provides for independent measurement of pressure or temperature using the sensors disclosed herein.

Abstract: A pressure sensor includes a body made of semiconductor material having a first type of conductivity and a pressure-sensitive structure having the first type of conductivity defining a suspended membrane. One or more piezoresistive elements having a second type of conductivity (P) are formed in the suspended membrane. The piezoresistive elements form, with the pressure-sensitive structure, respective junction diodes. A temperature sensing method includes: generating a first current between conduction terminals common to the junction diodes; detecting a first voltage value between the common conduction terminals when the first current is supplied; and correlating the detected first voltage value to a value of temperature of the diodes. The temperature value thus calculated can be used for correcting the voltage signal generated at output by the pressure sensor when the latter is operated for sensing an applied outside pressure which deforms the suspended membrane.

Abstract: This disclosure provides example methods, devices, and systems for a flexible interconnect structure for a sensor assembly. In one configuration, a flexible interconnect structure may couple a first portion of a differential sensor structure to a second portion of the differential sensor structure. Further, the flexible interconnect structure may couple the differential sensor structure to an external component such as a circuit board, used to receive measurement information from the differential sensor.

Abstract: In a method for ascertaining an offset of an output signal of an evaluation circuit integrated in a sensor, the output signal is supplied to a control unit which analyzes the output signal, and a reset of the evaluation circuit for the adjustment of the output signal to a base level is performed prior to each measuring operation of the sensor, and the control unit ascertains the offset of the output signal of the evaluation circuit upon an occurrence of a start signal output by the evaluation circuit.

Abstract: There is provided a water leakage detection device including a water leakage detection unit which is configured to detect water leakage, a water leakage detection circuit unit which is configured to be driven by a DC voltage from a DC power source and apply an AC voltage for detecting water leakage to the water leakage detection unit, and is configured to determine whether water is leaking based on a detection signal of the water leakage detection unit. The water leakage detection unit includes an insulating transformer having a primary side and a secondary side, the second side being connected to the water leakage detection unit, and a water leakage detection determining unit which is connected to the primary side of the insulating transformer.

Abstract: A mobile terminal device includes: a housing; a measuring unit configured to measure an air pressure inside the housing; a detecting unit configured to detect whether the housing is sealed based on a change in the air pressure measured by the measuring unit while an operation is being conducted by a user; and a notifying unit configured to notify the user of a detection result of the detecting unit.

Abstract: Testing methods and equipment are provided for fast, non-destructive testing of the quality of seal and/or integrity of a package. According to certain embodiments, dynamic impact characterization is used to determine whether a loss of pressure due to a leak in the package occurs. The methods and equipment can be used in-line with product packaging processes. According to one embodiment, an initial pressure is applied to a package under test. A region of the package is impacted with a force sufficient to create a disturbance to the package while not destroying the package by using an impacting rod. Force sensors/transducers contact with the package and spaced a distance away from the impact region of the package detect a force signature from the impact. The existence of a leak is determined by evaluating the force signature.

Abstract: An apparatus for determining optical fiber array polarity is disclosed. The apparatus may be used to determine optical signal loss or intensity. An adapter may be used to couple the apparatus to a variety of optical fiber connectors. The apparatus includes a position sensing detector and processing circuitry. The position sensing detector includes a sensor that receives optical signals and electrodes that output respective output signals in response to receipt of an optical signal. The processing circuitry receives the output signals and identifies locations at which the optical signals were incident on the sensor. The processing circuitry also determines the receiving position in the optical array of an optical fiber and a polarity of the optical array based on the receiving position and a corresponding transmitting position. The processing circuitry may determine an intensity or loss of the optical signal based on an aggregate of the output signals.

Abstract: In a method for determining a dead time in the response characteristic of an exhaust gas sensor in order to determine an exhaust gas state quantity in an exhaust gas duct of an internal combustion engine, the dead time is determined from a measured output signal of the exhaust gas sensor and a comparison signal. An undelayed comparison signal is determined, and a cross-correlation is formed between the measured output signal and the comparison signal delayed by a model dead time selected in such a way that the cross-correlation function assumes a maximum, and the dead time of the measured output signal is set equal to the selected model dead time.

Abstract: A device for measuring vibration amplitudes of the blade tips in a turbomachine is provided. The device includes a support mounted in an orifice of a casing of a turbomachine, in which are housed two optical guides for the emission and reception of a light signal exiting inside the casing across from the tips of the blades of a turbine wheel Each optical guide includes an optical fiber connected by a mechanical connector to a needle of which the core is made of a material able to transmit a light signal and which is resistant to temperatures less than or equal to 1100° C. and which exits at its distal end in the casing across from the blade tips.

Abstract: An optical probe (10) includes an inner tube (30), and a light-redirecting element (54) disposed at a distal end (56) of the inner tube. The light-redirecting element is supported at the distal end by an affixing structure (57) not attached to an optically-working surface (58) of the light-redirecting element.

Abstract: The present invention discloses a gradually-ascending spiraled passive sampler for measuring sediment-water diffusion flux of organic polutants, which comprises a sediment pore-water sampler and a water sampler arranged above the sediment pore-water sampler, wherein a plurality of sediment sampling units are vertically arranged in the sediment pore-water sampler, and the water sampler is provided with a plurality of water sampling units arranged transversely along the vertical direction in sequence.

Abstract: An exhaust sampling system for an engine is provided. The exhaust sampling system may include a source of exhaust gas, an exhaust collection unit including at least one collection bag that selectively receives the exhaust gas, and a first sample probe in fluid communication with the source of exhaust gas that selectively supplies the at least one collection bag with the exhaust gas at an extraction rate. The exhaust sampling system may also include a controller that permits flow of the exhaust gas from the first sample probe to the at least one collection bag in a first state and prevents flow of the exhaust gas from the first sample probe to the at least one collection bag in a second state. The controller may control the extraction rate of the first sample probe based on a time during a test phase at which the engine is switched to an ON state.

Abstract: A container or vial for the cryopreservation and/or vitrification and storage of a biological sample, including cellular samples and embryos is described. The container comprises a sealable closure that isolates a biological sample held in the container lumen from the external environment and is suitable for storage of the sample in liquid nitrogen. Methods for introducing and sealing biological samples within the container for cryopreservation and/or vitrification and storage are also described.

Abstract: A system and method that enables automated reagent dispensing for tissue stainers. The stainers receive staining protocols from a central controller. The central controller may control a plurality of stainers simultaneously. The stainers obtain information provided on slide identifiers which is communicated to the central controller. The central controller determines a particular staining protocol to apply to a particular slide. The staining protocol is downloaded to the stainer which enables the stainer to operate without additional communication with the central controller. A user may manually initiate a staining protocol or the central controller may operate the stainers on a scheduled basis.

Abstract: A sample preparation system for an analytical system for determining a measured variable of a sample liquid, comprising: a transport unit connected with a sample taking location via a first fluid conducting line; a sample collecting unit, which serves the analytical system as a staging area for automated removal of liquid samples, based on which the measured variable is determined; a filter unit arranged between the sample taking location and the transport unit; and at least one reservoir connected via a second fluid conducting line with the filter unit for providing a cleaning medium for cleaning the filter unit; wherein the transport unit is embodied to transport sample liquid from the sample taking location through the filter unit into the sample collecting unit. The cleaning medium includes an oxidizing agent.

Abstract: The present invention is to provide a pretreatment method that allows RNA to be detected promptly and simply. RNA degradation activity due to lactoferrin present in the human rhinal mucosa is inhibited, for example, by adding iron ion and carbonate ion to a biological sample that contains the human rhinal mucosa. With the pretreated biological sample, an RNA virus gene can be amplified by a reverse transcriptase. Iron ion and carbonate ion can also inhibit reverse transcriptase inhibition due to lysozyme C contained in the human rhinal mucosa. Further, it is preferable to remove the envelope of the RNA virus by adding SDS to the biological sample that contains the human rhinal mucosa.

Abstract: An embedder is provided. The embedder includes a body having a working stand; a paraffin reservoir disposed in the body; a paraffin dispenser disposed on the body and connected with the paraffin reservoir; a heated working plate disposed on the working stand; a cooling plate disposed on the working stand; a tray disposed on the working stand; and a ceramic layer at least formed on an inner wall surface of the tray. With the embedder according to the present invention, by coating the ceramic layer on the inner wall surface of the tray to form an anti-scratch protective layer, when removing solidified paraffin wax on the inner wall surface of the tray, it is possible to avoid scratching the inner wall surface of the tray so as to avoid the damage to the surface of the tray.

Abstract: An adapter for a sliding head of a sample processing system is provided that includes a plate and a magnet mounting recess wall. The plate includes a top surface, a bottom surface, a front wall extending between the top surface and the bottom surface, and a back wall extending between the top surface and the bottom surface. The magnet mounting recess wall is mounted to the top surface. The magnet mounting recess wall is configured to accommodate a magnet of a sliding head of a sample processing system. At least a portion of the bottom surface is curved in a first direction from the front wall to the back wall and is concave relative to the top surface.

Abstract: A system and method of taking a sample of hydrogen gas and reducing the hydrogen concentration by a factor greater than 1×108 while increasing the partial pressure of the contaminating gases by a factor greater than 100, so that extremely low levels of contamination can be accurately detected. A sample of hydrogen gas is captured. Only the hydrogen gas is removed leaving all the contaminating gases in the collection chamber. This causes the total pressure of the gas sample within the collection chamber to decrease dramatically since most of the gas was hydrogen. All the contaminants remain in the collection chamber. None are lost through pumping. As such, the concentration of contaminants within the remaining sample increases dramatically. The residual partial pressures of the contaminating gases within the collection chamber and can now be measured by a variety of techniques.

Abstract: Disclosed herein are devices for measuring, at one or more time points, one or more properties or changes in properties of a fluid sample. The devices may comprise a chamber defining an internal volume of the device suitable for receiving and retaining the fluid sample; a plurality of layers, the plurality comprising at least a first layer below the chamber, at least a second layer above the chamber, and a substrate layer between the first and second layers, wherein: the substrate layer is linked to at least one suspended element located within the chamber; the suspended element is linked to the substrate layer by at least two compliant structures located within the chamber; and the suspended element is configured to oscillate upon application of an actuating signal to at least one electrically conductive path, which runs across at least two of the compliant structures and the suspended element. Related methods and uses are also disclosed.

Abstract: A method for measuring the properties of a fluid that uses a torsionally resonant structure having a base structure; at least two parallel tines affixed to the base structure and projecting in the same direction from the base structure; and wherein the base structure is sufficiently compliant as to mutually couple the tines so that they behave as a single resonator when the tines are driven in synchronized manner. The torsionally resonant structure is immersed in the fluid to be measured and a tine driving mechanism is used to drive the tines torsionally. A tine movement sensing mechanism form measurements of tine movement response to the driving mechanism and the measurements of tine movement to form measurements of fluid properties.

Abstract: Apparatus and methods to determine structural integrity of composites are described herein. One described example method for determining sufficiency of structural integration of a composite structure for an aircraft includes applying a fluid droplet to a surface of the composite structure, determining a three-dimensional contact angle between the surface and a portion of the droplet, comparing the three-dimensional contact angle to a threshold angle, and determining whether the structural integration of the composite structure is sufficient based on the comparison.

Abstract: An object is to measure a mechanical property of a fluid at a temporal resolution of at least 100 [?s]. Therefore, a method comprising: causing a droplet 21 to fly by ejecting a fluid to be measured from a nozzle 11a as the droplet 21; generating an electric field in a space around a flight path 22 of the droplet 21 by applying a voltage to an electrode arranged in the vicinity of the flight path 22; deforming the droplet 21 in a way of contactless deformation with a dielectric force induced by the electric field; and measuring a mechanical property of the fluid based on temporal variation of deformation state of the droplet 21 after deforming the droplet 21.

Abstract: The invention relates to a particle detector including a substrate made of a semiconductor material, in which at least one through-cavity is formed, defined by an input section and an output section, wherein the input section thereof is to be connected to an airflow source, the substrate supporting: an optical means including at least one laser source, and at least one waveguide connected to the at least one laser source and leading into the vicinity of the output section of the cavity; and a photodetector located near the output section of the cavity and offset relative to the optical axis of the optical means.

Abstract: A smoke detection unit has two identical smoke detectors juxtaposed horizontally, each made up of at least one smoke sensor positioned beneath and coupled to a measuring chamber fitted with walls. The detectors are encapsulated in a rigid cavity having an upper base and a lower cover positioned opposite the smoke sensors. A base is formed by the walls of each of the two measuring chambers. A method further fixes the smoke detection unit to a bearing structure.

Abstract: In the case of an impactor (1) with an impact plate (7) and a classifying nozzle (2) directed at this impact plate (7), in the case of which the impact plate (7) is formed as an electronically readable resonantly oscillating, mass-sensitive element (7, 33), it is proposed to move the oscillating crystal (7, 33) held in an impact plate holder (8) in relation to the static classifying nozzle (2) by a motor (12) during the operation of the impactor (1).

Abstract: Apparatus and methods determine a permeation characteristic of a challenge chemical for a chemical protective material. A processor retrieves barrier characteristics of the chemical protective material for which the permeation characteristic is to be determined from a computer memory. Information regarding the challenge chemical is obtained. A temperature is received of the chemical protective material for which the permeation characteristic is to be determined. The permeation characteristic is determined from the temperature, the barrier characteristics, and the information regarding the challenge chemical.

Abstract: A method for detecting particles in a fluid stream includes generating a measurement field that can be passed through by the fluid stream, acquiring and evaluating measurement values of the fluid stream passing through the measurement field, and detecting at least one particle by way of a distinctive sequence of measurement values. Each of the distinctive successions of measurement values is acquired and evaluated to determine if a particle or a gas bubble is passing through the measurement field.

Abstract: System and method for point-of-care monitoring of neutrophils in a peritoneal dialysis sample with the use of a microfluidic system. The immunoassay based chip is configured to bound neutrophils to a microfluidic channel surface while leaving auxiliary cells and particles unattached and suspended in the sample and flushable with a wash buffer. Data representing images of neutrophils, formed by an (optionally lensless) imaging system, are processed to determine a count of neutrophils based on statistical parameters including characteristics of the microfluidic channel.

Abstract: A corrosivity associated with each of multiple locations near, on, or within a structure exposed to an environment that can corrode the structure is determined. Each of multiple sensor nodes is mounted at a corresponding one of the locations and measures environmental sensor information using one or more environmental sensors and corrosion sensor information using one or more corrosion sensors. The environmental sensor information is processed to obtain for the sensing node a first atmospheric corrosivity category value in accordance with a corrosivity classification system, and the corrosion sensor information is processed to obtain a second atmospheric corrosivity category value for the sensing node in accordance with the corrosivity classification system. One or more of the first and second atmospheric corrosivity category values is provided for use in determining a corrosion classification value for each of the locations.

Abstract: Disclosed are apparatus and methods for determining a structure or process parameter value of a target of interest on a semiconductor wafer. A plurality of collection patterns are defined for a spatial light beam controller positioned at a pupil image plane of a metrology tool. For each collection pattern, a signal is collected from a sensor of the metrology tool, and each collected signal represents a combination of a plurality of signals that the spatial light beam controller samples, using each collection pattern, from a pupil image of the target of interest. The collection patterns are selected so that the pupil image is reconstructable based on the collection patterns and their corresponding collection signals. The collected signal for each of the collection patterns is analyzed to determine a structure or process parameter value for the target of interest.

Abstract: MIR spectroscopy systems comprising hierarchical spectral dispersion that enables fine spectral resolution and high sensitivity spectroscopy are disclosed. Hierarchical spectral dispersion is derived by employing at least two diffractive lens arrays, located on either side of a test sample, each receiving input radiation having an input spectral range and distributing the input radiation into a plurality of output signals, each having a fraction of the spectral range of the input radiation. As a result, the signal multiplication factor of the two arrays is multiplied in a manner that mitigates the propagation of wavelength harmonics through the system. In some embodiments, an emitter array comprising a plurality of spectrally selective emitters provides the input MIR radiation to a spectroscopy system. In some embodiments, spectrally selective detectors are used to detect narrow spectral components in the radiation after they have passed through the test sample.

Abstract: Incoherent millimeter wave, sub-millimeter wave and terahertz test signals are used to probe metal substrates that are covered by a protective coating or outer layer, such as paint or thermal insulation, obscuring direct assessment of the substrate. The incoherent test signals, which may be from a naturally occurring passive source (such as the sky) and/or from an active noise source, provide signal dispersion and angular variation of the test signals with respect to angular incidence to the substrate. Illumination of the substrate permits differentiation between un-corroded and corroded sections of the sample because reflectivity (and emissivity) from a metal-based substrate is heavily dependent on the surface resistivity which in turn is dependent on the corroded state.

Abstract: An apparatus for measuring a hemoglobin concentration includes a reference light source unit, a light and heat light source unit configured to emit a light and heat beam for generating a light and heat effect, an accommodation unit configured to accommodate obtained blood samples, an image acquisition unit configured to write a primary pattern formed after the reference beam emitted by the reference light source unit is incident on the accommodation unit and a secondary pattern formed under an influence of a light and heat effect after the light and heat beam emitted by the light and heat light source unit is incident on the accommodation unit, and a concentration calculation unit electrically connected to the image acquisition unit and configured to calculate a hemoglobin concentration based on a difference between the primary pattern and the secondary pattern.

Abstract: Among other things, a first surface is configured to receive a sample and is to be used in a microscopy device. There is a second surface to be moved into a predefined position relative to the first surface to form a sample space that is between the first surface and the second surface and contains at least part of the sample. There is a mechanism configured to move the second surface from an initial position into the predefined position to form the sample space. When the sample is in place on the first surface, the motion of the second surface includes a trajectory that is not solely a linear motion of the second surface towards the first surface.

Abstract: Provided herein are magnetic silica fluorescent nanoparticles and fluorescent silica nanoparticles comprising an aggregation induced emission luminogen and magnetite nanoparticles and use of the same as a fluorescent bioprobe for intracellular imaging and a protein carrier. Also provided are processes for preparing and fabricating the same.

Abstract: An arrangement for in situ measurement of at least one oxygen partial pressure within a solids heap, including: at least one measuring transducer arranged within the solids heap for locally registering oxygen partial pressure, wherein each measuring transducer is embodied to output a measurement signal representing oxygen partial pressure to a superordinated unit, which is arranged outside the solids heap and is embodied to receive and to process the measurement signals of each measuring transducer.

Abstract: A fluorescence detection system is provided. The fluorescence detection system includes a light source adapted to emit excitation light; a sample unit in which a sample is disposed; a first optical fiber adapted to connect the light source to the sample unit; an avalanche photodiode array detector adapted to receive fluorescent light generated by the sample when the sample is irradiated with the excitation light; and a second optical fiber adapted to connect the sample unit to the avalanche photodiode array detector, wherein the second optical fiber has a numerical aperture of equal to or greater than about 0.15 and the second optical fiber is positioned such that a longitudinal axis of the second optical fiber is orthogonal to a longitudinal axis of the first optical fiber. A method for detecting fluorescence and a computer-implemented method for detecting fluorescence are also provided.

Abstract: The invention provides a fluoroscopy apparatus including an image-capturing device that acquires a fluorescence image of a subject; a sensitivity adjusting portion that sets a sensitivity of the image-capturing device to fluorescence on the basis of a gradation value of the fluorescence image; a notifying portion that extracts a lesion part from the fluorescence image acquired by the image-capturing device with the sensitivity set by the sensitivity adjusting portion and presents it to an operator; and a display switching portion that displays the fluorescence image on a display unit when the sensitivity in the image-capturing device is equal to or less than a predetermined threshold and that presents information showing the existence of the lesion part on the notifying portion when the sensitivity is greater than the predetermined threshold.

Abstract: The invention provides a high resolution, wide dynamic range, multi-color detection platform for microfluidic analyzers/instruments and methods. The detection platform uses multiple high gain semiconductor optical sensors for the detection of luminescence from cellular or biological samples. The digitized outputs from these sensors are combined and weighted in a signal processing unit, using pre-determined algorithms for each color, which optimize the resolution in each of these high gain semiconductor optical sensors while extending the dynamic range of the detection platform.

Abstract: The invention is a surface plasmon resonance (SPR) sensor to determine the presence and quantity of biological or chemical entities in an analyte. The sensor comprises a metal periodic structure deposited as a thin layer of a noble metal, comprising a one dimensional array of nanoslits or a two dimensional array of nanoholes on a transparent dielectric substrate, a nm-thick layer of transparent dielectric protection layer on top of the metal periodic structure and a functionalization layer, which acts as a binding layer to biological or biochemical entities in an analyte that is in contact with the functionaliztion layer.

Abstract: In a Surface-Enhanced Raman Scattering (SERS) substrate and the manufacturing method thereof, the SERS substrate includes a low thermal conductivity base and a plurality of metal nanoparticles (NPs). The surface of the low thermal conductivity substrate has a first surface, and the first surface has a plurality of ripple micro/nano structures. The plurality of metal NPs are non-continuously densely arranged on the ripple micro/nano structures of the first surface. The metal NPs have a height difference along the ripple micro/nano structures, and form a 3D electric field enhanced region. The manufacturing methods includes sputtering a metal nano-thin film on a surface of a low thermal conductivity base, and the surface of the low thermal conductivity base has a plurality of ripple micro/nano structures; using laser to ablate the metal nano-thin film; and forming a plurality of metal NPs, which are non-continuously densely arranged.

Abstract: The invention is related to an optode for determining chemical parameters of a sample wherein the optode consists of a polymer matrix consisting of sulfonated polyether ether ketone (SPEEK) in which a sensor dye is immobilized or more than one sensor dye is immobilized, wherein at least one of the immobilized sensor dyes is pH-sensitive. In addition, the present invention also concerns a method for determining the pH of a sample in which the invention-related optode is used.