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 device to measure the amount of light able to transmit through a liquid. The device uses a light detector and multiple light emitting diodes (LED's) along with an optical unit such that the light detector, LED's, and an optical unit define a path of light emitted by each individual LED or subgroup of LED's and detected by the detector. The device uses a structure designed to surround the LED's and light detector such that the structure allows the device to be immersed in the liquid and such that the structure is shaped to allow a volume of liquid to be between the LED's and detector, intersecting the light path.

Methods and systems for gas detection are provided. Aspects include determining a target gas for detection in a sampling chamber, determining one or more target characteristics of light based on the target gas, operating a light source to transmit the light through a sampling chamber to an optical element, operating an active optical element to modulate the light based on the one or more target characteristics of the light, operating a filter to receive the light from the optical element and separate the light in to a first light portion and a second light portion, operating the photodetector to receive the first light portion from the filter, and analyzing the first light portion to determine a presence of the target gas in the sampling chamber.

An optical sensor for determining the concentration of polycyclic aromatic hydrocarbons in a medium incudes a light source configured to emit transmitted light having a wavelength of less than 300 nm into the medium; a detector for receiving received light, wherein the detector is configured at least for receiving received light having a wavelength of 300 nm to 400 nm, wherein the transmitted light is converted into received light by means of fluorescence in the medium as a function of the concentration of polycyclic aromatic hydrocarbons, wherein a detector signal is generated from the received light; and a data processing unit configured to determine the concentration of polycyclic aromatic hydrocarbons using the detector signal, wherein the data processing unit controls the light source such that the light source emits modulated transmitted light according to a duty cycle. Methods of using the optical sensor are further disclosed.

A high-throughput optofluidic device for detecting fluorescent droplets is disclosed. The device uses time-domain encoded optofluidics to detect a high rate of droplets passing through parallel microfluidic channels. A light source modulated with a minimally correlating maximum length sequences is used to illuminate the droplets as they pass through the microfluidic device. By correlating the resulting signal with the expected pattern, each pattern formed by passing droplets can be resolved to identify individual droplets.

A method for measuring hemoglobin concentration in a whole blood sample is disclosed. The method may include mixing a whole blood sample with a lysing agent, followed by manual agitation, flowing the whole blood or mixture into a reservoir of a sensor, the sensor comprising a transparent portion configured to allow an optical measurement of an absorbance or reflectance of the whole blood sample in the reservoir of the sensor; detecting, using an analyzer into which at least a portion of the sensor has been inserted, the whole blood sample in the reservoir of the sensor; upon detecting the liquid whole blood sample in the reservoir, optically measuring an absorbance or reflectance of the whole blood sample using a light source and a detector in the analyzer; and determining a concentration of hemoglobin in the whole blood sample based on the measured absorbance or reflectance and a calibration curve that relates the absorbance or reflectance to the concentration of hemoglobin in the whole blood sample.

A spectrometer system may be used to determine one or more spectra of an object, and the one or more spectra may be associated with one or more attributes of the object that are relevant to the user. While the spectrometer system can take many forms, in many instances the system comprises a spectrometer and a processing device in communication with the spectrometer and with a remote server, wherein the spectrometer is physically integrated with an apparatus. The apparatus may have a function different than that of the spectrometer, such as a consumer appliance or device.

A weak light detection system includes an excitation light radiator that irradiates a test piece with excitation light in an excitation light radiation pattern modulated by an error correction code sequence provided by applying an error correction code coding scheme to a predetermined transmitted information sequence, a light receiver that receives light stimulated by the excitation light at the test piece, a received code sequence identifier that identifies a received code sequence based on a change in the intensity of the light received by the light receiver, and a signal processor that applies an error correction code decoding scheme to the received code sequence to generate a decoded information sequence, compares the transmitted information sequence with the decoded information sequence, and determines that the test piece has emitted light according to the excitation light radiation pattern in a case where the transmitted information sequence coincides with the decoded information sequence.

An optical sensor system may include a light source. The optical sensor system may include a concentrator component proximate to the light source and configured to concentrate light from the light source with respect to a measurement target. The optical sensor system may include a collection component that includes an array of at least two components configured to receive light reflected or transmitted from the measurement target. The optical sensor system may include may a sensor. The optical sensor system may include a filter provided between the collection component and the sensor.

A gas analyzer includes an oxidation device and a subsequent photometer, wherein the oxidation device has a reaction chamber located in an exhaust gas path and a heating chamber downstream thereof, where an ultraviolet light source generates ozone from residual oxygen content of the exhaust gas within the reaction chamber to convert nitrogen monoxide into nitrogen dioxide in the exhaust gas, nitrogen oxides and excess ozone are broken down into nitrogen dioxide and oxygen in the heating chamber, the photometer outputs the measured nitrogen dioxide concentration as nitrogen oxide concentration of the untreated exhaust gas, and where an additional photometer is located in the exhaust gas path between the reaction chamber and the heating chamber which, via light absorption, measures the ozone concentration in the partially treated exhaust gas and outputs the same as oxygen concentration of the untreated exhaust gas.