Abstract:
A spectral reflectance sensor including: a light source for emitting a modulated beam of red light; a light source for emitting a modulated beam of near infrared light; a receiver for receiving reflected light produced by either the red source or the near infrared source; a receiver for receiving incident light from either the red source or the infrared source; a signal conditioner responsive to the modulation such that the signals produced by the receivers in response to reflected and incident light from the source can be discriminated from signals produced by ambient light; and a microprocessor having an input such that the microprocessor can determine the intensities of incident red light, reflected red light; incident near infrared light; and reflected near infrared light. From these intensities, and by knowing the growing days since emergence or planting, the sensor can calculate the mid-growing season nitrogen fertilizer requirements of a plant.
Abstract:
A system and method for focusing infrared detectors operable at cryogenic temperatures. The invention includes a sensor (10) for detecting electromagnetic energy comprising a first detector (14) operable over a first temperature range and a predetermined number of auxiliary detectors (12) operable over a second temperature range, wherein the auxiliary detectors (12) are adjacent to and in the same optical plane as the first detector (14). In the illustrative embodiment, the energy is infrared or visible light, the first temperature range is a range of cryogenic temperatures, and the second temperature range is a range of ambient temperatures. The first detector (14) is a focal plane array and the auxiliary detectors (12) are uncooled detector arrays. In the preferred embodiment, the focal plane array (14) and the uncooled detectors (12) are disposed on a common substrate. In accordance with the teachings of the present invention, the novel sensor (10) can be used to focus an optical system at cryogenic temperatures. The inventive method includes illuminating energy onto the sensor (10) through the optical system at ambient temperatures and then adjusting the position of the sensor (10) until maximum illumination is received by the auxiliary detectors (12). This determines the location of the focal plane of the system at ambient temperatures. The location of the focal plane at cryogenic temperatures can then be calculated using the location of the focal plane at ambient and a model of the thermal characteristics of the system.
Abstract:
A gain control technique for controlling the sensitivity of a passive infra-red motion detector. A manually adjustable gain control element such as a potentiometer is coupled to the PIR amplifier circuit at the final amplification stage so as to apply a greater potential difference across the gain control element to retard the deleterious effects of corrosion or other conduction-reducing influences and so that noise induced in the leads from the gain control to the circuit will not undergo any significant amplification compared with the desired signal from the PIR sensor.
Abstract:
An infrared (IR) radiation source (20, 50) includes an envelope (22), at least a portion (26) of which is IR transmissive, and a molecular gas species (23), contained in the envelope, which gas species is thermally excited to emit IR radiation in a discrete spectrum characteristic of the species, substantially without heating the envelope.
Abstract:
A description is given of a device and a method for determining the temperature of a cooking vessel placed on a hotplate of a heating appliance, e.g. on the glass ceramic plate of an inductive cooker, in the vicinity of a heating zone. In the vicinity of the heating zone is applied to the top of the hotplate at least one flat measuring element, e.g. formed by a colour coating and whose top surface comes into flat contact with the cooking vessel bottom on setting down the cooking vessel. As a result the temperature of the measuring element, by heat conduction, reliably matches the cooking vessel temperature, so that by determining the measuring element temperature it is possible to determine the cooking vessel temperature. The measuring element can serve as a reference measuring surface for infrared temperature measurement through the hotplate, the precision of the temperature measurement not being dependent on the emission capacity of the set down cooking vessel.
Abstract:
A method for distinguishing a kind of plastic materials, by preparing a test piece of a plastic material; measuring an infrared spectrum of the test piece by attenuated total reflection spectroscopy; and comparing the obtained infrared spectrum with an infrared spectrum of a known plastic. The test piece has a section. The infrared spectrum of the test piece is measured by bringing the crystal for attenuated total reflection spectroscopy into contact with the section of the test piece.
Abstract:
An image reading method for forming an image on a transmission original irradiated with visible light and infrared light by an image forming optical system and reading the image by reading means, comprising an image forming magnification correction step of correcting a difference between the image forming magnification of a visible-light image and the image forming magnification of an infrared-light image by the image forming optical system, so that the image reading apparatus can be miniaturized and simplified and defects such as foreign matters and flaws on the original can adequately be corrected.
Abstract:
A method of processing data from at least one spectrophotometer characterized by the steps of transferring the data from the spectrophotometer to a control processing unit, processing the data at the central processing unit, and transferring the processed data to the output device.
Abstract:
A flame sensor comprises a filter which blocks light in an infrared ray region, a filter which blocks stray light, a narrow band filter which passes only light of a band corresponding to a line spectrum of carbonic acid gas resonance radiation generated by a flame, and a broad band filter which passes light of a band which is broader than the band corresponding to the line spectrum, and a plurality of light reception elements which convert lights passing through the narrow and broad band filters to electric signals, the flame sensor judging flame when a difference between intensities of the electric signals is equal to or more than a predetermined value and a ratio between the intensities of the electric signals is within a predetermined range, by assuming that transmission band widths of the narrow and broad band filters are equal, is provided.
Abstract:
The present invention provides a method and apparatus for detecting a presence of an analyte in a fluid medium. Specifically, the present invention provides a detection probe comprising an analyte affinity compound which has a higher affinity for the analyte in a fluid medium than the fluid medium itself. In this manner, the analyte in the fluid medium is concentrated onto the detection probe. The present invention also provides a method for using the same in qualitative or quantitative analysis of the analyte in a fluid medium.