An optical rain sensor device includes a first light emitting element adapted to emit a first light pulse toward an inner surface of a transparent substrate, a second light emitting element adapted to emit a second light pulse toward the inner surface of the transparent substrate, a photodetector adapted to detect a light from the first light pulse and the second light pulse that is reflected by the inner surface of the transparent substrate, and a rain sensor controller. The rain sensor controller includes a regulated current source adapted to apply a compensation current signal at a terminal of the second light emitting element based on a regulation signal, so that a total current across the second light emitting element is increased or decreased to reduce an imbalance between the first light pulse and the second light pulse.

A sensor platform for the assessment of the condition and quality of fluids while in service is based on a combination of solid-state light sources (LEDs) and detectors housed within a single integrated package. The sensor platform configured to be standalone in operation and comprises interfacing optics and acquisition and processing electronics. The sensor platform is configured to obtain inputs from multiple stimulus points and correlates these to changes in the overall composition or condition of the fluid. The sensing method can be described as a combination of a differential sensor, by monitoring changes from the normal status of the fluid, and an inferential sensor where changes are interpreted in terms of global impact rather than specific localized changes in component concentration.

An instrument for processing and/or measuring a biological process contains a sample processing system, an excitation source, an excitation optical system, an optical sensor, and an emission optical system. The sample processing system is configured to retain a first sample holder and a second sample holder, wherein the number of sample cells is different for each sample holder or a characteristic dimension for the first sample cells is different from that of the second sample holder. The instrument also includes an excitation source temperature controller comprising a temperature sensor that is coupled to the excitation source. The temperature controller is configured to produce a first target temperature when the first sample holder is retained by the instrument and to produce a second target temperature when the second sample holder is retained by the instrument.

An instrument for processing and/or measuring a biological process contains a sample processing system, an excitation source, an excitation optical system, an optical sensor, and an emission optical system. The sample processing system is configured to retain a first sample holder and a second sample holder, wherein the number of sample cells is different for each sample holder or a characteristic dimension for the first sample cells is different from that of the second sample holder. The instrument also includes an excitation source temperature controller comprising a temperature sensor that is coupled to the excitation source. The temperature controller is configured to produce a first target temperature when the first sample holder is retained by the instrument and to produce a second target temperature when the second sample holder is retained by the instrument.

Disclosed is a method for measuring the absorbance of light of a substance in a solution in a measuring cell, said method comprising the steps of: transmitting a first light beam from a light source towards a beam splitter; dividing the first light beam into a signal light ray and a reference light ray by the beam splitter; modulating the signal light ray; modulating the reference light ray; providing the measuring cell such that the signal light ray passes through the measuring cell; detecting a signal in a detector, which signal is the combined signal intensity of the signal light ray and the reference light ray detected by the detector; performing synchronous detection of the detected signal in order to reconstruct the intensities of the signal light ray and the reference light ray from the combined signal detected by the detector, said synchronous detection being based on the modulation performed to the signal light ray and the reference light ray. Disclosed also is a measuring device for carrying out said method

A measurement system for measuring blood characteristics includes a controller, an emitter, a sensor, and a reference sensor. The emitter emits light at a plurality of wavelengths from a first side of a blood flow channel to a second side of the blood flow channel The sensor is provided on the second side of the blood flow channel. The reference sensor is provided on the first side of the blood flow channel The controller compensates measurements from the sensor based upon measurements from the reference sensor. The reference sensor may be disposed in a position to increase noise immunity of the measurement system. The measurement system may be connected to or part of a dialysis system.

Disclosed is a method for measuring the absorbance of light of a substance in a solution in a measuring cell (23; 223), said method comprising the steps of: transmitting (S1) a first light beam (27; 27) from a light source (25; 25) towards a beam splitter (29; 29); dividing (S3) the first light beam (27; 27) into a signal light ray (31; 31) and a reference light ray (33; 33) by the beam splitter (29; 29); modulating (S5) the signal light ray (31; 31); modulating the reference light ray (33; 33); providing (S9) the measuring cell (23; 23) such that the signal light ray (31; 31) passes through the measuring cell; detecting (S11) a signal in a detectoR (39; 39), which signal is the combined signal intensity of the signal light ray (31; 31) and the reference light ray (33; 33) detected by the detector (39; 39); performing synchronous detection (S15) of the detected signal in order to reconstruct the intensities of the signal light ray (31; 31) and the reference light ray (33; 33) from the combined signal detected by the detector (39; 39), said synchronous detection being based on the modulation performed to the signal light ray and the reference light ray. Disclosed also is a measuring device for carrying out said method

A measurement system for measuring blood characteristics includes a controller, an emitter, a sensor, a reference photo sensor, and a mask. The emitter emits light at a plurality of wavelengths from a first side of a blood flow channel to a second side of the blood flow channel. The sensor is provided on the second side of the blood flow channel. The reference photo sensor is provided on the first side of the blood flow channel. The mask is provided on the first side blocking reflected light other than from the light from the emitter to enter the reference photo sensor. The controller compensates measurements from the sensor based upon measurements from the reference photo sensor.

An embodiment of a gas analyzer is described that comprises a light source configured to produce a substantially collimated first beam with a diverging angle of less than about 15 degrees; a gas cell comprising an inlet configured to introduce a gas into the gas cell, an outlet configured to remove the gas from the gas cell, and a plurality of mirrors configured to reflect the substantially collimated first beam within the gas cell; and a detector configured to generate a signal in response to the substantially collimated first beam.

An object of the present invention is to quickly stabilize a light amount of an LED light source device used in absorbance analysis and to suppress the fluctuation of the temperature due to disturbance. In an LED light source device according to the present invention, an LED substrate is disposed on a spacer, the substrate and the spacer are brought into contact with at least one of a device housing and a device lid, and a thermal conductivity of the substrate and a thermal conductivity of the spacer are higher than a thermal conductivity of the housing and a thermal conductivity of the lid.