Abstract:
A device for measuring in situ, the optical density of a sample in a medium, in which the immersed sample has a main part with a slot at one end. A mobile part can be lodged in this slot. This mobile part has an open chamber which moves with the mobile part into the slot. This open chamber will contain a sample and will be aligned with an optical device in the housing, when moved into the slot. The mobile part and open chamber are, therefore, movable between an open position in which the medium to be studied circulates in the chamber, to a closed position when the mobile part is lodged in the slot whereat the open chamber is isolated from the medium to be studied. Measurement is carried out while the device is in the closed position by measuring the optical density of the isolated medium.
Abstract:
Reference cell (8) for use with a fibre optic probe (1) comprising a base wall (11), upstanding walls (12) each having an optical window (13, 15), and a top wall (14) having a further optical window (16) adapted to allow light to pass to and from a fibre optic probe. The base wall (11) comprises a reflector (19) which reflects incident light from the fibre optic probe back to said probe (1). The top wall (14) has an attachment for receiving an emitting and a receiving end of a fibre optic probe (1). The cell (8) allows use of standard fibre optic probe (1) with other optical equipment when the path length and the probe optical characteristics require validation to international standards. The calibration of the probe (1) is analogous to calibration of laboratory spectrophotometers and can therefore be validated. The device (8) enables probes (1) to be used for applications where precision and accuracy are essential.
Abstract:
An apparatus and related method for optical calibration of spectrophotometers is described. The apparatus is a calibration plate including one or more cuvettes filled with solutions of interest. The cuvettes are sealed to prevent evaporation. The cuvettes also possess a compressible component to allow for expansion of the solution and a bubble control apparatus to ensure that the compressible component does not intersect the beam path. A piece of neutral density glass is optionally included in the apparatus to track optical changes of the solutions over time.
Abstract:
A compact analyzer for dry biochemical analysis of blood samples, integrating onto a common chassis (11): a measuring chamber (20) adapted to receive a disposable rotor (13) including microtanks (13A, 13B) containing dry reagents, a digital dilution module (21) of fixed or variable ratio defined as a function of the species of the sample to be analyzed, a sample centrifuging module (12) adapted, inside the measuring chamber, to centrifuge the rotor and position it angularly, an optical module adapted to apply beams of light to microtanks of the rotor, this optical module including a flash-lamp type light source (14) and a reference light sensor (16), an electronic processing and control system (23, 24, 25) including an external memory reader (26) adapted to read a portable external memory (27) containing at least information characteristic of at least the disposable rotor in use.
Abstract:
In an optical instrument, a fiber optic probe is provided to irradiate a sample with visible NIR and ultraviolet light. Glass fibers carry the visible and NIR light to the probe from a visible and NIR light source and quartz fibers carry ultraviolet light to the probe from an ultraviolet source. Glass fibers carry visible and NIR light emanating from the sample to a spectrometer having a fixed grating and an array of photodetectors to receive the spectrum dispersed by the grating within the spectrometer housing. Amplifiers are also contained in the spectrometer housing severally connected to the photodetectors to amplify the output signals of the photodetectors. The probe is provided with a standard white sample pivotal into position to receive the light from the visible light source. A computer is programmed to provide automatic calibrating whenever the temperature within the housing changes more than a predetermined small amount. The automatic calibration is carried out by pivoting the white standard into position and computing calibration values from the resulting photodector outputs. Automatic calibration is also provided when the ratio of output signals from selected ones of the photodetectors changes by more than a predetermined small percentage.
Abstract:
Reference cell (8) for use with a fiber optic probe (1) comprising a base wall (11), upstanding walls (12) each having an optical window (13, 15), and a top wall (14) having a further optical window (16) adapted to allow light to pass to and from a fiber optic probe. The base wall (11) comprises a reflector (19) which reflects incident light from the fiber optic probe back to said probe (1). The top wall (14) has an attachment for receiving an emitting and a receiving end of a fiber optic probe (1). The cell (8) allows use of standard fiber optic probe (1) with other optical equipment when the path length and the probe optical characteristics require validation to international standards. The calibration of the probe (1) is analogous to calibration of laboratory spectrophotometers and can therefore be validated. The device (8) enables probes (1) to be used for applications where precision and accuracy are essential.
Abstract:
The photometer is calibrated by using a permanently built-in installation of four, similarly configured chambers in a good heat conducting carrier which is slidably interposed between sample and reference chambers on one hand and the detection structure on the other hand. One pair of these chambers is placed in the paths during measurement and is filled with inert gas, the other pair has one chamber filled with calibration gas, the other one with inert gas. All chambers are closed with similar windows.
Abstract:
A spectroanalytical gas measuring apparatus has a radiation source (36), a transmitting condensor (19), an objective (13) and a beam divider (11) which deflects at least a part of the radiation reflected back to the apparatus by a reflector (40) to a polychromator or spectrometer (32). The transmitted radiation falls after the beam divider (11) onto a deflecting mirror (12) which is adjustable between two positions and which directs the light to an objective reflector (13). The objective reflector (13) reflects the radiation to a follow-up mirror (15) arranged opposite to the beam passage opening (14). At least one long and one short focal length objective reflector (13) are provided in order to ensure different ranges of distance in conjunction with the adjustable deflecting mirror (12).
Abstract:
An apparatus and related method for optical calibration of spectrophotometers is described. The apparatus is a calibration plate including one or more cuvettes filled with solutions of interest. The cuvettes are sealed to prevent evaporation. The cuvettes also possess a compressible component to allow for expansion of the solution and a bubble control apparatus to ensure that the compressible component does not intersect the beam path. A piece of neutral density glass is optionally included in the apparatus to track optical changes of the solutions over time.
Abstract:
A non-dispersive infrared gas analyzer especially adapted for measuring the concentrations of HC, CO and CO.sub.2 in a vehicle exhaust includes a sample chamber for holding a sample gas, a radiation emitter for directing a beam through the chamber and a detector for indicating the amount of radiation absorbed. A plurality of filters each of which transmit radiation at an absorption band of a gas component to be detected are alternatingly positioned in the radiation path to produce a time-multiplexed signal having concentration information for all gases. The time-multiplexed detector output is corrected for gain and offset errors "on-the-fly", without requiring demultiplexing, through the use of an analog multiplier circuit. The correction factors are themselves determined without demultiplexing the detector output signal.