An arrangement for measuring gas concentrations in a gas absorption method, wherein the arrangement includes a plurality of light sources, a measuring cell, at least one measuring receiver and an evaluation apparatus. The measuring cell has a narrow, longitudinally-extended beam path with an entrance-side opening diameter B and an absorption length L with L>B, wherein the measuring cell has a gas inlet and a gas outlet wherein a plurality of light sources of different wavelength spectra is grouped into a first light source group wherein an optical homogeniser is interposed between the first light source group and the measuring cell, wherein, in particular, the homogeniser is coupled to the light source group directly or via a common optical assembly.

A measurement system configured to examine a sample. The system comprises an internally reflective element, a contact member, an actuator, an optical assembly, a sensor, and a controller. The contact member and the reflective element are configured to apply a force to the sample. The optical assembly is configured to scan the sample. Whereby prior to the scan, an initial force is applied to the sample, and after the scan, a resulting force is applied to the sample. The sensor is configured to detect the resulting force applied to the sample, and the controller is configured to receive a signal from the sensor indicative of the detected resulting force. The controller is further configured to control the actuator to adjust the force applied to the sample by the contact member and the internally reflective element from the resulting force to the initial force.

An optical measurement system measurement system for examining a sample. The measurement system comprises an internally reflective element, a stage, an optical assembly, a chassis, and a sensor. The internally reflective element has a contact surface. The stage is positioned below the internally reflective element. The stage and the internally reflective element are configured to apply a force to the sample. The optical assembly comprises a light source and a light detector. The optical assembly is configured to scan the sample by directing source light from the light source towards the contact surface and detecting source light optically interacting with the contact surface by the light detector. The chassis is configured to support the optical assembly and the internally reflective element. The sensor is mounted to the chassis and configured to detect the force applied to the sample by the internally reflective element and the stage.

The concentration measurement device 100 includes an electric unit 20 having a light source 22 and a photodetector 24, a fluid unit 10 having a measurement cell 1, optical fibers 11 and 12 for connecting the electric unit 20 and the fluid unit 10 and is configured to measure the concentration of the fluid in the measurement cell by detecting the light incident from the light source 22 to the measurement cell and then emitted from the measurement cell by the photodetector 24, where optical connection parts 32 and 34 connected to the optical fibers 11, 12 and the light source 22 or the photodetector 24 are integrally provided in the electric unit 20.

In order to make it possible to conduct a zero calibration even though an interference gas exists in a measurement area of a detector, a light absorbance analysis apparatus includes a detector that detects an intensity of light that transmits a gas, a total pressure sensor that measures a total pressure of the gas, an absorbance calculating part that calculates an absorbance based on an output value of the detector and a previously set zero reference value, a partial pressure—absorbance relation storing part that stores a partial pressure—absorbance relational data that indicates a relationship between a partial pressure of an interference gas that exists in a measurement area of the detector and an absorbance calculated by the absorbance calculating part, and a partial pressure calculating part that calculates an interference gas partial pressure as a partial pressure of the interference gas.

An optical gas concentration measurement apparatus is disclosed. The optical gas concentration measurement apparatus includes a thermally insulated enclosure that has a gas sample cell situated within. A thermally-insulating, light-guiding element passes through an access port of the thermally insulated enclosure and is configured to direct light from a light source outside of the thermally insulated enclosure to the gas sample cell. A light detector outside of the thermally insulated enclosure is optically coupled to the gas sample cell and an electronic assembly outside of the thermally insulated enclosure is configured to receive information from the light detector.

A detection device includes a substrate, first electrodes formed on a first surface of the substrate, a responsive layer, and second electrodes formed on a first surface of the responsive layer, each of the second electrodes are capacitively coupled to one of the first electrodes and each second electrode is connected to a power supply to provide driving power.

There is provided a method for measuring a composition of a gas circulating through a plasma-based detector, the plasma-based detector having a discharge chamber defining an internal volume and having discharge electrodes configured to apply a plasma-generating field across the discharge chamber. The method includes ramping a voltage until it reaches a breakdown voltage to generate a plasma, detecting the presence of the plasma, determining a pressure based on the breakdown voltage upon detection of the presence of the plasma, operating the detector at an operation voltage greater than the breakdown voltage, performing measurement(s) on the plasma, generating a detector signal based the measurement(s) and compensating the detector signal based on the determined pressure to obtain a compensated detector signal, the compensated detector signal being representative of the composition of the gas. A plasma-based detector for measuring the composition of the gas is also provided.

A concentration measurement device 100 includes a light source 22 for generating incident light to a measurement space 10A, a photodetector 24 for receiving light emitted from the measurement space, and an arithmetic control circuit 26 for calculating a concentration of a measurement fluid on the basis of an output of the photodetector, and the light source includes a first light-emitting element 22a for generating light having a first wavelength, and a second light-emitting element 22b for generating light having a second wavelength, and the concentration measurement device is configured so as to calculate the concentration using either light of the first wavelength or the second wavelength on the basis of the pressure or temperature of the measurement fluid.

An embodiment of a system for measuring trace gas concentration is described that comprises a laser absorption spectrometer configured to detect an absorbance measure from a trace gas, as well as a temperature value and a pressure value that correspond to an environment in a gas cell; and a computer having executable code stored thereon configured to perform a method comprising: receiving the absorbance value, the temperature value, and the pressure value; defining a fitting range associated with the trace gas; applying a curve fitting model in the fitting range to the absorbance value using the temperature value and the pressure value as model parameters; and producing a concentration measure of the trace gas.