A device for measuring the flocculation threshold of a colloidal medium by varying the intensity of the luminous flux, and a method for measuring the flocculation threshold of a colloidal medium by the addition of aliphatic solvent using the device, including the step of determining the flocculation after the addition of the amount of aliphatic solvent necessary for flocculation.

A system for measuring with the aid of light absorption spectrometry the concentration of one or more analytes in porewater in soil, the system comprising: one or more monitoring unit(s), each monitoring unit comprising a porewater sampler (1), an optical flow cell (2) with a tube connecting the liquid inlet port of said optical flow cell to said porewater sampler; and vacuum arrangement to enable extraction of porewater; at least one light source (5) for generating a light beam to be transmitted through said optical flow cell (2); and at least one detector (8) for obtaining spectral information from the beam exiting said optical flow cell. A method of measurement is also provided.

Assays (100) may be performed with a luminometer (400) having a chassis (405) that may include a reaction vessel chamber (610). The luminometer (400) may also include a light passage (640) that intersects the reaction vessel chamber (610). The luminometer (400) may also include a cap (415) that, when in a closed configuration, prevents light emitted by external sources from entering the reaction vessel chamber (610) and from entering the light passage (640). The cap (415) may provide access to the reaction vessel chamber (610) when in an open configuration. The luminometer (400) may also include a calibration light source (460) optically coupled to one end of the light passage (640) and a light detector (630) optically coupled to another end of the light passage (640). The light detector (630) may include a sensing element for receiving light from the light passage (640).

A smoke detection device main body of a portable smoke detector can switch smoke detection sensitivity. At the start of operation, the smoke detection sensitivity of the portable smoke detector is equal to or higher than a smoke detection sensitivity of a fixed smoke detector that detects smoke in a monitoring area. At this time, switching of smoke detection sensitivity does not work. After the fixed smoke detector detects smoke generation, when the portable smoke detector is used to locate the smoke generation position while moving in the monitoring area, an operation is performed from an initial sensitivity. When a predetermined smoke detection signal is detected while using the portable smoke detector to identify the smoke generation position, the smoke detection sensitivity switching is activated, and the smoke detection sensitivity is changed accordingly. By lowering the smoke detection sensitivity, the smoke generation position is narrowed down and identified.

The present invention belongs to the technical field of trace gas detection, and relates to a multi-cavity semi-open resonant photoacoustic cell and a multi-gas simultaneous measurement system. The photoacoustic cell includes multiple resonant cavities. Each resonant cavity has a unique length and a unique resonant frequency, so each resonant cavity corresponds to one to-be-measured gas. A sensitive diaphragm of an acoustic sensor is fixed on one end face of the photoacoustic cell. Photoacoustic signals of different frequencies generated in the resonant cavities act on the sensitive diaphragm of the acoustic sensor, causing the sensitive diaphragm of the acoustic sensor to vibrate periodically. Concentration information of multiple to-be-measured gases can be obtained by analyzing the vibration of the sensitive diaphragm of the acoustic sensor.

An automatic analysis device has a plurality of types of photometers having different quantitative ranges, and an analysis control unit for quantifying the desired component in specimens based on measurement values of one or more photometers selected from among the plurality of types of photometers. The analysis control unit: sets a switching region in an overlap region of respective quantitative ranges of the plurality of types of photometers, said switching region having a greater width than does the variation in quantitative values of the desired component based on the measurement values of photometers having the same specimen; compares the quantitative value of a quantitative range portion that corresponds to the switching region and the quantitative values of the desired component based on the measurement values of the photometers; and selects a photometer to be used in quantitative output of the desired component from among the plurality of types of photometers.

A spectral imaging system configured to obtain spectral measurements in a plurality of spectral regions is described herein. The spectral imaging system comprises at least one optical detecting unit having a spectral response corresponding to a plurality of absorption peaks of a target chemical species. In an embodiment, the optical detecting unit may comprise an optical detector array, and one or more optical filters configured to selectively pass light in a spectral range, wherein a convolution of the responsivity of the optical detector array and the transmission spectrum of the one or more optical filters has a first peak in mid-wave infrared spectral region between 3-4 microns corresponding to a first absorption peak of methane and a second peak in a long-wave infrared spectral region between 6-8 microns corresponding to a second absorption peak of methane.

Disclosed herein are systems, sensors and methods for determining a concentration of an analyte in a fluid. The system comprises a sensor configured to generate a differential response to a constant concentration of the analyte; and an acquisition device configured to determine the concentration of the analyte from the differential response. The method comprises exposing the fluid to a sensor which is configured to generate a differential response to a constant concentration of the analyte; and measuring a differential response of the sensor to the analyte.

An automatic analysis device has a plurality of types of photometers having different quantitative ranges, and an analysis control unit for quantifying the desired component in specimens based on measurement values of one or more photometers selected from among the plurality of types of photometers. The analysis control unit: sets a switching region in an overlap region of respective quantitative ranges of the plurality of types of photometers, said switching region having a greater width than does the variation in quantitative values of the desired component based on the measurement values of photometers having the same specimen; compares the quantitative value of a quantitative range portion that corresponds to the switching region and the quantitative values of the desired component based on the measurement values of the photometers; and selects a photometer to be used in quantitative output of the desired component from among the plurality of types of photometers.

A spectral imaging system configured to obtain spectral measurements in a plurality of spectral regions is described herein. The spectral imaging system comprises at least one optical detecting unit having a spectral response corresponding to a plurality of absorption peaks of a target chemical species. In an embodiment, the optical detecting unit may comprise an optical detector array, and one or more optical filters configured to selectively pass light in a spectral range, wherein a convolution of the responsivity of the optical detector array and the transmission spectrum of the one or more optical filters has a first peak in mid-wave infrared spectral region between 3-4 microns corresponding to a first absorption peak of methane and a second peak in a long-wave infrared spectral region between 6-8 microns corresponding to a second absorption peak of methane.