Abstract:
A sensor (1) for measuring moisture is formed of a laser diode module (2) comprising two laser diodes (3), a first photodiode (4), a second photodiode (5), a lock-in amplifier (6) of the first photodiode, a lock-in amplifier (7) of the second photodiode, a power regulator (8) of the laser diode, an optical link (11), a module (9) for data acquisition, and a device (10) for processing data, displaying measurement results and controlling the method of measurement, wherein the optical link (11) is provided with a first leg (15) that optically links the laser diode (3) and the first photodiode (4), wherewith it provides for compensation of instability of the laser diode (3) due to temperature and mechanical influences.
Abstract:
A device for determining the composition of a mixture of fluids by spectral absorption, comprises: a radiation source; a detector for detecting radiation that has been attenuated by the mixture; and a device for separating the radiation into a wavelength band corresponding to an absorption band of one of the fluids, a wavelength band corresponding to an absorption band of another of the fluids, and at least one reference wavelength band substantially adjacent to each of the absorption bands, and especially adjacent to each side of the absorption band or group of absorption bands. The device may be used to determine the composition of mixtures of oil, water and gaseous hydrocarbons in oil wells where there is a very large degree of time varying scattering e.g. Rayleigh and Mie scattering due to turbulence. In addition, a device for outputting the ratio of values of a pair of signals, e.g the output from such a device, comprises a detector (72, 76) for sampling each signal; a variable-gain amplifier (82) for amplifying each of the detected signals with the same gain and outputting each of the amplified signals. The variable- gain amplifier includes a feedback loop (90, 94) for receiving one of the amplified signals output by the amplifier and adjusting the gain of the amplifier to be inversely proportional thereto, so that the other of the pair of signals is output by the amplifier with reference to the said one of the signals.
Abstract:
An apparatus for determining the quality of meat comprising a probe (1) to be inserted into a piece of meat which is to be examined and reflection measuring means placed in the probe having a light emitter (2) and a light receiver (3). A reference light receiver (4) which controls the supply to the light emitter (2) is placed in the probe near the light emitter. The servo link formed will compensate for the fluctuating efficiency of the light emitter (2) and the light receiver (3). The intensity of the light emitter may automatically be kept at a constant level.
Abstract:
A method for identifying a target polymer (20) comprises translocating a target polymer (20) having detectable elements (22), such as fluorophores (22), through an analysing device (24) comprising a nanopore (28) having a detection window (40), wherein the analysing device (24) is capable of plasmon resonance to produce a localised electromagnetic field which defines the detection window (40) detecting the detectable elements (22) as they pass through the detection window (40) to produce a distribution profile of the detectable elements (22) along the target polymer (20) and identifying the target polymer (20) by comparing the distribution profile to a reference set of distribution profiles for known polymers. In a preferred embodiment the target polymer (20) is a nucleic acid and the detectable elements (22) are oligonucleotides complimentary to at least two adjacent nucleotides therein. Exemplified is the use of 6-mer oligonucleotides.
Abstract:
A respiratory CO₂ detector (10) comprising an infrared lamp source (44) and an infrared detector (50) responsive thereto forming an optical path for detecting the change in CO₂ concentration, or an obstruction in a cuvette (42). The output of the infrared detector (50) provides a continuous high and low voltage signal to be applied to a feedback control loop (12) and to an output circuit (14). The feedback control loop (12) includes a peak detector (22), a contamination detector (24), a pulse-width modulator (26) and a low pass filter (28), the latter providing a DC bias on the infrared lamp (44). The peak detector (22) is connected to the pulse-width modulator (26) to maintain the lamp voltage constant and is connected to comparators (56,62) to compare both outputs of the peak and contamination detectors (22,24). The contamination detector (24) will respond to blockage in the cuvette (42). The output control circuit (14) includes a sample-and-hold circuit (30) to direct the high and low voltage signal from the detector to a subtractor (32), the output of which is then inverted to provide a high quality waveform.
Abstract:
A semi-automated biological sample analyzer and subsystems are provided to simultaneously perform a plurality of enzyme immuno assays for himan IgE class antibodies specific to a panel of preselected allergens in each of a plurality of biological samples. A carousel is provided to position and hold a plurality of reaction cartridges. Each reaction cartridge includes a plurality of isolated test sites formed in a two dimensional array in a solid phase binding layer contained within a reaction well which is adapted to contain a biological sample to be assayed. The carousel and cartridges contain structures which cooperate to precisely position the cartridges in each of three separate dimensions so that each cartridge is positioned uniformly. An optical reader operating on a principle of diffuse reflectance is provided to read the results of the assays from each test site of each cartridge. Also provided is a subsystem which provides predetermined lot-specific assay calibration data which is useful for normalizing the results of various assays with respect to predetermined common standard values.
Abstract:
An apparatus of measuring a small scale property of a sheet, the apparatus includes: a first light source for illuminating the sheet moving with respect to the illumination; a detector for forming a total intensity of reflection of the light illuminating the moving sheet by each detection; a detected dimension of the reflection on the sheet in the direction of the movement being limited the same as or shorter than a lowest acceptable spatial resolution of the measurement; a duration of each detection being equal to or shorter than the lowest acceptable spatial resolution divided by a speed of the moving sheet; and a processing unit for forming information about a small scale variation of gloss of the sheet on the basis of the detections by the detector.
Abstract:
A device for determining the composition of a mixture of fluids that flow along a pipe, which comprises: a radiation source for illuminating the mixture with radiation; a detector for detecting radiation that has been attenuated by the mixture; a device for monitoring the flow rate of fluid along the pipe and outputting a signal indicative of the flow rate. The device includes a device for adjusting the intensity of radiation emitted by the radiation source in response to the signal indicative of the flow rate so that the intensity of the radiation source is reduced if the flow rate reduces.
Abstract:
A semi-automated biological sample analyzer and subsystems are provided to simultaneously perform a plurality of enzyme immuno assays for himan IgE class antibodies specific to a panel of preselected allergens in each of a plurality of biological samples. A carousel is provided to position and hold a plurality of reaction cartridges. Each reaction cartridge includes a plurality of isolated test sites formed in a two dimensional array in a solid phase binding layer contained within a reaction well which is adapted to contain a biological sample to be assayed. The carousel and cartridges contain structures which cooperate to precisely position the cartridges in each of three separate dimensions so that each cartridge is positioned uniformly. An optical reader operating on a principle of diffuse reflectance is provided to read the results of the assays from each test site of each cartridge. Also provided is a subsystem which provides predetermined lot-specific assay calibration data which is useful for normalizing the results of various assays with respect to predetermined common standard values.