Abstract: A plasma lamp is disclosed. The plasma lamp includes a gas containment structure configured to contain a gas and generate a plasma within the gas containment structure. The gas containment structure is formed from a glass material transparent to illumination from a pump laser and the broadband radiation emitted by the plasma. The gas containment structure includes a glass wall and the glass within the glass wall includes an OH concentration distribution that varies across a thickness of the glass wall.

Abstract: Systems and methods for detecting determining a volume of urine in an absorbent article such as a diaper. A diaper loading application obtains a first measurement of ambient light received from a photodetector while a light source is off and a second measurement from the photodetector while the light source is transmitting light on an absorbent article. The application determines a normalized measurement of light reflected from an absorbent article by removing an ambient light signal from the second measurement based on the first measurement. The application determines, from the normalized measurement, a presence of urine in the absorbent article. The application further determines an estimated volume of urine in the absorbent article, wherein the determining is based on an elapsed time since the presence of urine and an activity state of an infant wearing the absorbent article.

Abstract: A sunlight exposure indicator device is disclosed that can determine the amount of time (e.g., hours) of PAR sunlight that occurs in a specific area for the optimal growth of a plant, as corresponds to the plant industry common designations of Full Shade, Partial Shade, Partial Sun and Full Sun. These designations can be used to determine plant selection for all types of plants including grasses, shrubs, flowers, vegetables and herbs, and trees. This device utilizes irreversible, slow-reacting, photochromic pigments applied to a substrate. Using multiple instances of this device will allow someone to easily test and accurately determine the amount of PAR sunlight (hours) received during a one-day sunlight cycle in multiple spots simultaneously. The sunlight exposure indicator device is a one-time-use, non-electronic, disposable device.

Abstract: Examples provide for an apparatus, method, and computer program for comparing the output of sensor cells in an arrangement of sensor cells in an area A, including a set of at least two measurement units. A measurement unit includes at least two sensor cells, wherein at least one sensor cell of at least one measurement unit includes a sensitive sensor cell, which is sensitive with respect to a measured quantity. The sensor cells are intermixed with each other. The apparatus further includes means for selecting output signals of sensor cells of the arrangement and means for determining a measured quantity or determining an intact sensor cell by comparing output signals of different measurement units.

Abstract: A telescoping sensor mount capable of systematically extending a sensor above a crop growth canopy. The telescoping sensor mount of the invention includes a foldaway tripod support system and is further capable of being powered with solar energy. The sensor mount and support are capable of extension and retraction and provide a solid base support for the sensors.

Abstract: A Random Number Generator includes a photon source, one or more photon detectors configured to detect at least one photon belonging to a flow of detected photons (?) generated by the photon source, an electronic sampler operatively associated with the photon detectors and configured to implement a logic method for the extraction of a binary sequence based on the arrival time of each one of the detected photons (?). In the Random Number Generator, the photon source and the photon detectors are adjacent to one another and integrated in a single semiconductor substrate.

Abstract: A device or system to measure a soiling level and/or soiling level non-uniformity, or power loss arising from soiling including soiling non-uniformity, representative of a PV module. In one respect, a device comprising at least a first transparent window and at least two sensors, wherein said sensors comprise a soiling sensor, an irradiance sensor, or a photovoltaic device, and wherein at least two of said sensors are configured to measure separate regions of said first transparent window and at least one of said sensors is a soiling sensor configured to measure a soiling level of said first transparent window or of a second transparent window substantially close to said first transparent window, and wherein from said measurements of said sensors said device determines a soiling level and/or a non-uniformity of said soiling level of said first transparent window.

Abstract: An avalanche photodiode includes a first-conductivity-type semiconductor layer; a first second-conductivity-type semiconductor layer; a second second-conductivity-type semiconductor layer; a third second-conductivity-type semiconductor layer; a fourth second-conductivity-type semiconductor layer; a fifth second-conductivity-type semiconductor layer. The first-conductivity-type semiconductor layer and the second second-conductivity-type semiconductor layer form an avalanche junction. The first and third second-conductivity-type semiconductor layers are electrically connected together via the fourth second-conductivity-type semiconductor layer such that the semiconductor substrate and the first-conductivity-type semiconductor layer are electrically isolated from each other.

Abstract: A non-attenuating meter determines optical energy of laser light in an absence of optical attenuation of the laser light and includes: a recipient mirror that: receives laser light that propagates in a primary propagation direction; produces profile light; transmits the profile light through the recipient mirror along the primary propagation direction; produces first reflected light from the laser light; and reflects the first reflected light along a secondary propagation direction; a profilometer in optical communication with the recipient mirror and that: receives the profile light from the recipient mirror along the primary propagation direction; and produces a profile signal from the profile light; a sensor mirror in optical communication with the recipient mirror and a passer mirror and that: receives the first reflected light from the recipient mirror along the secondary propagation direction; produces, in a tertiary direction, a sensor force from the first reflected light; communicates the sensor force

Abstract: A light sensing apparatus includes: an arrangement of light sensing pixels, one or more pixels each associated with a noise floor and able to detect a triggering level of incoming light above the noise floor from a corresponding portion of a scene; readout circuitry to process and reset the triggering pixels; and an automatic gain control (AGC) to raise the noise floor of one or more pixels. Sometimes, the light sensing apparatus is part of a seeker that includes control circuitry to dynamically control the AGC to raise the noise floor of one or more pixels by an adjustable amount that varies in relation to the distance between the seeker and an intended target. Sometimes, the control circuitry dynamically controls the AGC in response to a concurrent triggering of two or more triggering pixels. or in response to a gain schedule corresponding to guiding the seeker to the intended target.

Abstract: A dual circuit current loading analysis apparatus enables the efficient testing of an electrical circuit, particularly those in vehicular applications. The apparatus electrically loads two circuits simultaneously and compares those readings to a battery or power source. Circuit input ports and ports to attach to the positive and negative sides of the battery are provided and attached to a microcontroller, voltage measurement device and load test device. The results of the test are indicated on a display and LEDs.

Abstract: Disclosed herein are various embodiments for laser apparatuses. In an example embodiment, the laser apparatus comprises (1) a laser-emitting epitaxial structure having a front and a back, wherein the laser-emitting epitaxial structure is back-emitting and comprises a plurality of laser regions within a single mesa structure, each laser region having an aperture through which laser beams are controllably emitted, (2) a micro-lens array located on the back of the laser-emitting epitaxial structure, wherein each micro-lens of the micro-lens array is aligned with a laser region of the laser-emitting epitaxial structure, and (3) a non-coherent beam combiner positioned to non-coherently combine a plurality of laser beams emitted from the apertures.

Abstract: A solar monitoring system for measuring solar radiation intensity comprising a tracking unit having two-axis movement comprising, head mounted with first and second irradiation measuring units, and a controller. The first irradiation measuring unit comprises a direct normal irradiance (DNI) sensor and the second irradiation measuring unit includes a diffuse horizontal irradiance (DHI) sensor and a global horizontal irradiance (GHI) sensor. The controller receives inputs from the sensors or a software program configured to control orientation of the image capturing head so that the DNI sensor is always exposed to the sun, and the shading disc is always directly between the DHI sensor and the sun.

Abstract: A method of re-configuring a lighting arrangement (120-170) used to light a scene (100) which is to be captured by an image capture device (110), the method including the steps of: obtaining an initial image of the scene (100) using an initial configuration (190) of the lighting arrangement; developing an image content map identifying at least one scene characteristic of at least a part of the scene (100) captured in the initial image; determining a desired aesthetic effect for a further image to be captured based on the scene (100); in accordance with the at least one scene characteristic identified in the image content map, selecting from a plurality of aesthetic factors at least one aesthetic factor involving adjustment in order to achieve the determined desired aesthetic effect for the further image; and developing at least one lighting parameter for re-configuring the lighting arrangement (120-170), wherein the at least one lighting parameter corresponds with the at least one selected aesthetic factor.

Abstract: Radiation-sensitive material embedded in a disposable radiochemistry device gives the device the additional capability of recording radiation dose, for readout at a later time. There is provided a device comprising means for the introduction of a precursor compound, means for the introduction of a radionuclide, a reaction vessel for reacting said precursor compound and said suitable source of a radionuclide to obtain a radiolabelled compound, and one or more pieces of radiation-sensitive material embedded into said device wherein at least one of said pieces is positioned to be exposed to radioactivity associated with said radiolabelled compound.

Abstract: A block-and-tackle transmission includes a timing belt input pinion, a timing belt, two or more shuttles, an output cable, and an output hub. The timing belt input pinion is for receiving input power. The timing belt is driven by the input pinion. The timing belt causes two shuttles of the two or more shuttles to move in opposing directions. Opposing ends of the output cable are pulled by two of the two or more shuttles. The output cable causes the output hub to transmit output power.

Abstract: A pulse wave sensor includes: a light emitting unit configured to emit light onto a living body; a light receiving unit configured to receive light transmitted through or reflected from the living body based on the light from the light emitting unit; a pulse wave detecting unit configured to detect a pulse wave of the living body based on a result of light reception by the light receiving unit when the light is emitted from the light emitting unit with a normal light emission intensity; and a light emission intensity adjusting unit configured to cause the light emitting unit to emit light with a predetermined test light emission intensity in a test period prior to the detection of the pulse wave, and set the normal light emission intensity using detection light reception intensity in the light receiving unit by the light emission and a predetermined reference light reception intensity.

Abstract: An optical random number generator has: a light source (2) for randomly emitting photons (9); an array (3) of single photon avalanche diodes for detecting the photons (9) provided by the light source (2), wherein the array (3) of single photon avalanche diodes is positioned in a predefined distance (d) to the light source (2); and a control (10) coupled to the array (3) of single photon avalanche diodes and for determining an arrival time of the photons (9) detected by each of the single photon avalanche diodes of the array (3) of single photon avalanche diodes, and for generating a random number on the basis of the arrival time.

Abstract: An optical measurement apparatus includes: a hollow cylindrical member having one plane with a first opening and the other plane with a second opening; a rotation mechanism for rotating the cylindrical member about a first axis; a support unit for arranging a light source at a measurement position which is on the first axis and from which the emitted light enters the cylindrical member through the first opening; a first reflection unit arranged inside the cylindrical member for reflecting the light emitted from the light source and entering through the first opening; a second reflection unit for reflecting the light inside the cylindrical member and propagating the light through the second opening along the first axis to the outside of the cylindrical member; and at least one third reflection unit for causing the light reflected by the first reflection unit to be incident on the second reflection unit.

Abstract: An objective lens driving unit including a moving structure to which an objective lens and a driving coil are operatively installed, a static structure which includes a magnetic circuit corresponding to the driving coil, a plurality of suspension wires each of which has a first end and a second end, the first end being operatively connected to the static structure, and the second end being operatively connected to the moving structure, and circuit boards operatively installed to the moving structure, the circuit boards including a plurality of wiring layers, wherein the wiring layers include first terminals to which the driving coil is connected and second terminals to which the second end of each of the plurality of is connected.

Abstract: A mobile apparatus is provided for measuring photometric characteristics of airport marker lights. The mobile apparatus includes a measuring rod configured to be moved above the marker lights to be checked, in light beams emitted by these marker lights, and a device for measuring the distance between the measuring rod and the marker lights to be checked. The measuring rod carries at least one photometric sensor and includes a device for acquiring and processing the signals emitted by the photometric sensor or sensors during its movement, as a function of the distance measured between the measuring rod and the marker lights to be checked. The device for acquisition and processing is configured to generate a set of data representing photometric characteristics of each marker light checked.

Abstract: The range image sensor is a range image sensor which is provided on a semiconductor substrate with an imaging region composed of a plurality of two-dimensionally arranged units (pixel P), thereby obtaining a range image on the basis of charge quantities QL, QR output from the units. One of the units is provided with a charge generating region (region outside a transfer electrode 5) where charges are generated in response to incident light, at least two semiconductor regions 3 which are arranged spatially apart to collect charges from the charge generating region, and a transfer electrode 5 which is installed at each periphery of the semiconductor region 3, given a charge transfer signal different in phase, and surrounding the semiconductor region 3.

Abstract: There is provided a semiconductor integrated circuit for an optical sensor for receiving environmental light through a cover member that attenuates visible light and transmits infrared light and a collecting lens, performing luminosity factor correction based on an amount of received light, and detecting an illuminance, wherein the semiconductor integrated circuit includes a first light receiving element having a first spectral property; a second light receiving element having a second spectral property; and a luminosity factor correction unit configured to perform the luminosity factor correction according to output of the first light receiving element and output of the second light receiving element, wherein the luminosity factor correction unit includes an AD conversion unit performed by time division on the output of the first light receiving element and the output of the second light receiving element, and a calculating unit subtracting digital signals obtained by the conversion.

Abstract: A luminous intensity test device includes an optical frequency converter, a display, and a processor. The optical frequency converter selectively converts at least a portion of light emitted by a light source into a digital signal. The display displays a color selection interface. The processor processes the digital signal and obtains the luminous intensity. When a tester inputs a color parameter into the color selection interface via an input device, the optical frequency converter converts a kind of light to the digital signal and then the processor processes the digital signal to obtain a luminous intensity and display the luminous intensity on the display.

Abstract: An electronic device may be provided with an image sensor for capturing digital images. The image sensor may be used as part of image-sensor-based ambient light sensing circuitry for producing ambient light sensor readings. The image-sensor-based ambient light sensing circuitry may include a reference array. The reference array may be formed from an array of light sensor elements that are matched to elements in the image sensor but that are covered with a light blocking material. Control circuitry can measure current flow into the reference array and the image sensor array and can use current measurements from these arrays in producing a calibrated ambient light sensor reading. The control circuitry may make current measurements by measuring a decay time associated with the voltage of a discharging capacitor. A comparator, pulse generator, and switch may be used in periodically recharging the capacitor. The capacitor may be adjusted to ensure accurate readings.

Abstract: A luminescence detecting apparatus and method for analyzing luminescent samples is disclosed. A detecting apparatus may be configured so that light from luminescent samples pass through a collimator, a first lens, a filter, and a camera lens, whereupon an image is created by the optics on the charge-coupled device (CCD) camera. The detecting apparatus may further include central processing control of all operations, multiple wavelength filter wheel, and/or a robot for handling of samples and reagents.

Abstract: A method for controlling a light source associated with an environment includes: receiving, over a wireless mesh network and by a control node corresponding to the light source, a first light intensity value for the environment from a first sensor node; calculating, by the control node, a resulting light intensity (RLI) value based on the first intensity value; determining, by the control node, that the RLI value exceeds a light intensity threshold; and modifying, by the control node and in response to determining the RLI value exceeds the light intensity threshold, an output of the first light source.

Abstract: Disclosed is an inspecting equipment for inspecting a light emission characteristic of a display screen includes: a carrying device provided for carrying the display screen, a cover device and a data analyzing device. The cover device has a detecting surface provided with a plurality of luminance detectors, and covers an emitting surface of the display screen to form a darkroom between the cover device and the detecting surface. A plurality of corresponding luminance information is generated by the luminance detectors provided for detecting a plurality of measuring zones of the emitting surface. The data analyzing device receives the luminance information and analyzes the light emission characteristic of the display screen according to the luminance information. And, it is thus able to rapidly inspect the light emission characteristic of the display screen during manufacture process, and is easy to be applied to a present producing line.

Abstract: An optical device is disclosed, including a surface emitting laser element having a surface emitting laser which emits a light in a direction which is perpendicular to a substrate face; a light receiving element which monitors the light of the surface emitting laser; a package provided with a region on which the surface emitting laser element and the light receiving element are provided; and a lid which has a window through which passes the light of the surface emitting laser, the window being formed with a transparent member, and which covers the surface emitting laser element and the light receiving element.

Abstract: For transferring optical energy, a first multimode wave guide transmits radiant energy with a homogenized beam to a first plurality of optical sensors of an array of optical sensors. The array measures the homogenized radiant energy. Each optical sensor of the first plurality of optical sensors measures a pixelized portion of the homogenized radiant energy. A method and system also perform the functions of the apparatus.

Abstract: The range image sensor is a range image sensor which is provided on a semiconductor substrate with an imaging region composed of a plurality of two-dimensionally arranged units (pixel P), thereby obtaining a range image on the basis of charge quantities QL, QR output from the units. One of the units is provided with a charge generating region (region outside a transfer electrode 5) where charges are generated in response to incident light, at least two semiconductor regions 3 which are arranged spatially apart to collect charges from the charge generating region, and a transfer electrode 5 which is installed at each periphery of the semiconductor region 3, given a charge transfer signal different in phase, and surrounding the semiconductor region 3.

Abstract: A light sensor is used to detect ambient light conditions. According to an example embodiment, a light sensor (112) detects color temperature and, in some instances, intensity characteristics of ambient light (120, 130, 140) in an environment and uses these detected characteristics (116) to determine the location of the sensor relative to natural and artificial light sources. This location determination is used to selectively operate circuits in a device such as a hand-held telephone, computer device or personal data assistant (PDA).

Abstract: A luminous intensity test device includes an optical frequency converter, a display, and a processor. The optical frequency converter selectively converts at least a portion of light emitted by a light source into a digital signal. The display displays a color selection interface. The processor processes the digital signal and obtains the luminous intensity. When a tester inputs a color parameter into the color selection interface via an input device, the optical frequency converter converts a kind of light to the digital signal and then the processor processes the digital signal to obtain a luminous intensity and display the luminous intensity on the display.

Abstract: A fiberized single photon sensitive spectrometer based on a 32-channel PMT sensor is highly sensitive with broad detection dynamic range. The spectrometer enables accurate and high speed detection, identification and analysis of biological samples labeled with multiple fluorescent markers, such as compositions of multi-color fluorescence signals or radiation emitted by multiple fluorescence dyes. A fiberized optical input of the spectrometer allows an easy and efficient coupling to any measurement system based on fiber collection of the analyzed fluorescence. The spectrometer provides highly accurate DNA sequencing. A 32 channel PMT single photon detector has a detection dynamic range of more than 20 bits and has a frame rate of about 3300 frames per second. The dynamic range of the detector's pixels reaches 108 photocounts per second.

Abstract: A noninvasive physiological sensor for measuring one or more physiological parameters of a medical patient can include a heat sink that can direct heat away from the light source.

Abstract: An optical measurement system includes a holder, a bracket, a plurality of optical sensors, a motor and a processing unit. The holder is provided for holding a test light source at the origin of a spherical coordinate system. The optical sensors are located on the bracket at different elevation angles with respect to the origin. Moreover, the optical sensors are spaced the same radial distance apart from the origin to aim at the test light source. The motor is configured to drive either the holder or the bracket to rotate such that the test light source at the origin is able to relatively rotate with respect to the optical sensors about a zenith axis of the spherical coordinate system. The processing unit is coupled to the optical sensors for processing of data captured from the optical sensors.

Abstract: A projection type display apparatus in which an inclination and a positional deviation of optical axes among a plurality of light sources can be easily corrected to obtain a high quality projection image. Green, blue and red laser beams emitted from light sources are converted into collimated beams by condenser lenses, and the positions and angles of the optical axes of the beams of the three colors are evaluated by position detection imaging device and angle detection imaging device, respectively. The positions and angles of the light sources are adjusted by respective actuators so that the positions and angles of the optical axes match each other. Consequently, the laser beams emitted from the light sources can be combined with high accuracy to thereby realize a high definition projection type display apparatus.

Abstract: A particulate detector (10) comprises a radiation source (12) arranged to emit radiation in at least first and second predetermined wavebands towards a sampling region (18) suspected of containing particulates, and a detection element (14), shielded from the radiation source (12), and arranged to detect radiation from the sampling region (18) at least first and second instances. The radiation source (12) is such that the emissions in the wavebands temporarily overlap. The detector is such that, at the instances at which the radiation is detected, the relative contributions from the emissions in each predetermined waveband are distinguishable, thereby allowing characteristics of the particulates to be determined. The radiation source (12) may comprise a light emitting diode (24).

Abstract: An area dosimeter for measuring the ambient equivalent dose of photon radiation with a diffuser, and a detector card with at least one pair of detection elements, preferably LiF-chips. A first of the two detection elements is positioned between two filters in order to spectrally filter the photon radiation. A second of the two detection elements is not positioned between such filters in order that the photon radiation arriving at the second detection element will have a different spectral distribution from the spectrally filtered photon radiation arriving at the first detection element. The two measurement values are used to obtain a weighted sum in order to achieve an optimized response characteristic.

Abstract: A system for analyzing smoke has a plurality of units, wherein each unit includes an optical emitter for alternately directing horizontally and vertically polarized light along a beam path, and into a smoke cloud, to generate scattered light. A horizontally polarized detector and a vertically polarized detector are positioned at different locations, but at a same distance and scattering angle relative to the beam path. Each unit has a different wavelength. A computer receives signals from the detectors of all units, in response to each emitter, for analysis of the smoke.

Abstract: A luminescence detecting apparatus and method for analyzing luminescent samples is disclosed. A detecting apparatus may be configured so that light from luminescent samples pass through a collimator, a a first lens, a filter, and a camera lens, whereupon an image is created by the optics on the charge-coupled device (CCD) camera. The detecting apparatus may further include central processing control of all operations, multiple wavelength filter wheel, and/or a robot for handling of samples and reagents.

Abstract: Generally described, one or more embodiments of the present disclosure are directed to pulse oximeter test instruments and methods for testing pulse oximeters. The pulse oximeter test instruments may be configured to sense light at different wavelengths simultaneously. In some embodiments, light pulses having a wavelength above a particular threshold may be detected and used to test measurements made by a pulse oximeter. In that regard, the pulse oximeter test instruments disclosed herein are able to provide improved accuracy and more reliable test results over prior art pulse oximeter test instruments.

Abstract: An avalanche photodiode is disclosed. The avalanche photodiode includes a substrate of a first conductivity type. A first well of a second conductivity type is formed within the substrate. A second well of the second conductivity type is formed substantially overlying and extending into the first well. A heavily doped region of the first conductivity type is formed substantially overlying and extending into the first well, the junction between the heavily doped region and the second well forming an avalanche multiplication region. A guard ring is formed from a first conductivity material positioned substantially about the periphery of the multiplication region at least partially underlying the heavily doped region. An outer well ring of the second conductivity type is formed about the perimeter of the deep well and the guard ring.

Abstract: An integrated circuit memory device includes a refresh control circuit that generates an internal memory refresh command signal having a period that is changed relative to a period of an external memory refresh command signal received by the memory device. This change in the period of the internal memory refresh command may be in response to detecting a change in temperature of the memory device. In particular, the refresh control circuit is configured so that the period of the internal memory refresh command signal is increased in response to detecting a reduction in temperature of the memory device.

Abstract: The present disclosure relates to a sensor having a set of photodetectors that are arranged at various locations to enable the measurement of blood glucose. The photodetectors are arranged across multiple locations. For example, the detector may comprise multiple photodetector arrays that are arranged to have a sufficient difference in mean path length to allow for noise cancellation and noise reduction. Walls may be used in the detector to separate individual photodetectors and prevent mixing of detected optical radiation between the different locations on the measurement site. A window may also be employed to facilitate the passing of optical radiation at various wavelengths for measuring glucose in the tissue.

Abstract: For transferring optical energy, a first multimode wave guide transmits radiant energy with a homogenized beam to a first plurality of optical sensors of an array of optical sensors. The array measures the homogenized radiant energy. Each optical sensor of the first plurality of optical sensors measures a pixelized portion of the homogenized radiant energy. A method and system also perform the functions of the apparatus.

Abstract: An optical measurement system includes a holder, a bracket, a plurality of optical sensors, a motor and a processing unit. The holder is provided for holding a test light source at the origin of a spherical coordinate system. The optical sensors are located on the bracket at different elevation angles with respect to the origin. Moreover, the optical sensors are spaced the same radial distance apart from the origin to aim at the test light source. The motor is configured to drive either the holder or the bracket to rotate such that the test light source at the origin is able to relatively rotate with respect to the optical sensors about a zenith axis of the spherical coordinate system. The processing unit is coupled to the optical sensors for processing of data captured from the optical sensors.

Abstract: A computer implemented method for utilizing a plurality of self-activating display shaping devices to provide shape adjustment information for a digital image projected on a display is disclosed. In one embodiment, the plurality of display shaping devices are automatically activated, the plurality of display shaping devices defining a desired digital image shape for a display. In addition, the plurality of display shaping devices is utilized to identify an actual projected digital image shape. The actual projected digital image shape is then compared with the desired digital image shape for the display. Correction information is then provided for adjusting the actual projected digital image shape to approximate the desired digital image shape for the display.

Abstract: A mobile device including a solar battery having a light-receiving surface provided on a casing of the mobile device, an illuminance detector that detects an illuminance of light incident on the casing, an output section that outputs a state of light incident on the light-receiving surface of the solar battery, and a controller that controls the output section based on the illuminance detected by the illuminance detector.

Abstract: A solar radiation detector comprises a shading element that casts a shadow over one of a number of sensors disposed about the shading element. The shading element and the sensors are spaced in relation to each other that the shadow cast by the shading element always falls on one of the sensors, completely shading that one sensor, while at the same time leaves at least another one of the sensor completely exposed to direct solar radiation. The completely shaded sensor measures substantially only diffuse solar radiation.