Abstract:
The present invention relates to a gas cell (1) for optical measurements of gas content and/or concentration comprising a cavity (1a), at least one aperture (11) for gas exchange, at least one first socket (12) for light emitting means (2) and at least one second socket (13) for light detecting means (3). The length of an optical measuring path (A) through the cavity (1a) is defined by a direct or indirect distance between a light emitting means (2) in the first socket (12) and a light detecting means (3) in the second socket (13). The present invention teaches that an epoxy mold compound is used to form at least the parts of the gas cell (1) that define the optical measuring path (A).
Abstract:
The improved sample chamber includes an elongated hollow tube (12) closed at one end (14) and having specularly-reflective inwardly facing surfaces (16). A source (26) of radiation and a detector (28) of radiation are mounted side by side in the open end of the hollow tube, both facing the closed end. A plurality of filtering apertures (20) are formed in the tube (12), and each aperture is covered by a sheet (22) of a semipermeable membrane that serves to prevent airborne particles larger than a predetermined size from entering the chamber while not interfering with the free diffusion of the gas to be measured into and out of the chamber. The use of an elongated hollow tube that is closed at one end results in no loss in the efficiency with which the radiation is conducted from the source to the detector while decreasing the external length of the chamber by 50 percent.
Abstract:
The improved sample chamber includes an elongated hollow tube (12) closed at one end (14) and having specularly-reflective inwardly facing surfaces (16). A source (26) of radiation and a detector (28) of radiation are mounted side by side in the open end of the hollow tube, both facing the closed end. A plurality of filtering apertures (20) are formed in the tube (12), and each aperture is covered by a sheet (22) of a semipermeable membrane that serves to prevent airborne particles larger than a predetermined size from entering the chamber while not interfering with the free diffusion of the gas to be measured into and out of the chamber. The use of an elongated hollow tube that is closed at one end results in no loss in the efficiency with which the radiation is conducted from the source to the detector while decreasing the external length of the chamber by 50 percent.
Abstract:
A sensor module and method for determining and imaging fluorescence lifetime based on the time-of-flight values are disclosed. The sensor module comprises an opaque housing (OH) having a first chamber (CH1) and a second chamber (CH2) which are separated by a non-transparent barrier (LB). Further, it comprises an optical emitter (OE) arranged in the first chamber (CH1) and configured to emit light through a first aperture (AP1). Pulsed excitation light of a specified wavelength is directed to optically excite a fluorescent probe (FP) positioned in the optical path of the excitation light. The module also comprises a detector (MD) arranged in the second chamber (CH2) and configured to detect through a second aperture (AP2) photons originating from the fluorescent probe (FP). The module further comprises: a measurement block (MB) configured to determine a temporal difference between an arrival time of one of the received photons with respect to the emission pulses; a histogram block (HIST) configured to accumulate the difference values in a histogram; a processing circuit (PRC) configured to compute time-of-flight values based on an evaluation of the histogram and then to compute a fluorescence lifetime from the time-of-flight values and generate an output signal (OS) being indicative of the fluorescence lifetime of the fluorescent probe; and a control unit (CU) configured to initiate pulsed emission of the optical emitter (OE).
Abstract:
A fluorescence analysis system may include a sensor head that has a light source configured to emit light into a flow of fluid, a detector configured to detect fluorescent emissions from the flow of fluid, and a temperature sensor. The system may also include a flow chamber that includes a housing defining a cavity into which the sensor head can be inserted. In some examples, the housing is configured such that, when a flow of fluid enters the housing, the flow of fluid divides into at least a major stream passing adjacent the light source and the detector and a minor stream passing adjacent the temperature sensor. Such a flow chamber may direct fluid past different sensors components while inhibiting a build-up of solids particles, the generation of air locks, or other flow issues attendant with continuous or semi-continuous online operation.
Abstract:
An optical flow cell (10) is disclosed having a two-piece shell (30) with a first portion (31) and a second portion (32). The first portion (31) provides a light entry aperture (38), and the second portion provides an imaging aperture (39). An inlet tube (34) and an outlet tube (35) are retained between the first portion (31) and the second portion (32) when said first portion (31) and second portion (32) are assembled. A viewing assembly (36) is retained between the first portion and the second portion when said first portion (31) and second portion (32) are assembled. The viewing assembly (36) includes a reference plate (98) and a flow channel (102). The flow channel (102) fluidly communicates with the inlet tube (34) and the outlet tube (35). The reference plate (98) extends from the shell (30) to serve as a repeatable reference point for properly positioning the optical flow cell (10).
Abstract:
A fluorescence analysis system may include a sensor head that has a light source configured to emit light into a flow of fluid, a detector configured to detect fluorescent emissions from the flow of fluid, and a temperature sensor. The system may also include a flow chamber that includes a housing defining a cavity into which the sensor head can be inserted. In some examples, the housing is configured such that, when a flow of fluid enters the housing, the flow of fluid divides into at least a major stream passing adjacent the light source and the detector and a minor stream passing adjacent the temperature sensor. Such a flow chamber may direct fluid past different sensors components while inhibiting a build-up of solids particles, the generation of air locks, or other flow issues attendant with continuous or semi-continuous online operation.
Abstract:
The invention relates to an optical sensor (1) for determining particle and/or dye concentrations in liquid or gaseous media and to a method for operating the same. The optical sensor (1) comprises at least one measuring head. The measuring head consists of an emitter unit (2) with a semiconductor emitting element (9), which emits visible emission light beams (8), and with a receiver unit (3) with a semiconductor receiving element (10). The portion of the emission light beams (8), which pass through an absorption section containing liquid or gaseous medium, is guided onto the receiving element (10). An evaluating unit (6) is coupled to the measuring head via electric leads (4, 4'), and the received signals, which are present at the output of the semiconductor receiving element (10), are evaluated inside said evaluating unit in order to determine the particle or die concentration.
Abstract:
A gas sample chamber (10) for use in a gas analyzer consists of an elongated hollow tube (21) having an inwardly-facing specularly-reflective surface (22) that permits the tube to function also as a light pipe for conducting radiation from a source (20) to a detector (16) through the sample gas. A number of apertures (24) in the wall of the elongated hollow tube permit the sample gas to enter and exit. Particles of smoke and dust of a size greater than 0.1 micron are kept out of the chamber by use of a semi-permeable membrane (28) that spans the apertures in the hollow tube. Condensation of the sample gas components is prevented by heating the sample chamber electrically to a temperature above the dew point of the component of concern.