Abstract:
The invention relates to a method and an arrangement for measuring the ambient temperature in barely accessible or hazardous locations, in particular in the proximity of textile, paper or similar webs or other work pieces or materials being conveyed, of which at least one property is determined by means of a methodical system, which requires at least the direct ambient temperature as a comparative or reference value. According to the invention, a pyrometric radiation meter known per se is used. A thermal radiator in thermal balance with the environment is positioned directly proximate to the material web. Detection of the heat radiation spectrum and hence an indirect determination of the ambient temperature is carried out by means of the pyrometer via said thermal radiator.
Abstract:
A realtime sensitivity correction method for use in an infrared imaging system, which compensates for possible sensitivity variations among a plurality of sensor elements constituting a infrared sensor device. The infrared imaging system comprises: an infrared sensor which accepts infrared rays emanating from a target object through an appropriate optical system, two reference heat sources, a sensitivity correction circuit composed of digital signal processors, RAM, and other components, a sensitivity correction sequence controller, and a video monitor. The system's scanning cycle consists of an effective scanning period and a non-effective scanning period. During a non-effective scanning period, the infrared sensor scans the high-temperature and normal-temperature reference heat sources. By averaging the detected values, high-temperature reference data and normal-temperature reference data are obtained. Sensitivity correction coefficients are then calculated from the high-temperature and normal-temperature reference data. In the subsequent effective scanning period, the infrared sensor scans the target object, and the resultant image data is corrected according to the sensitivity correction coefficients.
Abstract:
Self calibrating a pyrometer includes taking two different temperatures thereby generating two voltage spectra, calculating the spectra ratio R of the two voltage spectra, determining the slope of the plot of the logarithm of the spectrum ratio versus c.sub.2 /.lambda. to arrive at a relationship between T.sub.1 and T.sub.2, solving for T.sub.1 within the spectra ratio, and arriving at a value for T.sub.2 by substituting experimentally measured values for R into the spectra ratio equation. This method is then repeated for the determination of T.sub.2. The pyrometer calibration constant h.sub..lambda. can then be determined by dividing the measured voltage spectra by the planck function at the known temperature (i.e., T.sub.1 or T.sub.2). Measurement of subsequent temperatures can now be determined by measuring the voltage spectra and dividing by the calibration constant h.sub..lambda. which will result in a planck function L.sub..lambda. (T) which can be solved to yield the surface temperature.
Abstract:
A self-calibrating radiometer comprising a block having a front surface for receiving incident radiation flux, an identically configured rear surface for receiving internally applied heat and a midportion for thermally insulating the rear surface from the front surface, the front surface being capable of absorbing as heat substantially all radiation flux incident thereupon and capable of reradiating substantially all of the absorbed heat, and the rear surface being capable of radiating substantially all heat applied thereto, a thermocouple configuration for sensing the heat radiated by each of the front and rear surfaces, an indicator for indicating any difference in the sensed heat, a heating element for applying enough heat to the rear surface so that no difference in heat radiated by the front and rear surfaces is indicated by the indicator, and a measuring circuit for measuring the heat applied to the rear surface, such measurement being indicative of the radiant flux incident on the front surface.
Abstract:
A shield plate that is used for non-contact measurement of a temperature of a measurement target is provided. The shield plate includes a base of which a temperature is adjustable. The base includes a central shield portion that is formed in the shield plate, an opening that is formed around the central shield portion, and a blackbody surface that is formed on one surface of the base to include a portion opposite to the opening with the central shield portion interposed therebetween and to radiate infrared rays.
Abstract:
Provided is a measuring method capable of accurately measuring the surface temperature of a surface to be measured, uninfluenced by the emissivity distribution of the surface to be measured. A surface to be measured having an emissivity distribution, a radiometer that measures a radiance distribution of the surface to be measured, and an auxiliary heat source installed in a specular reflection position from the radiometer with respect to the surface to be measured are prepared, radiances of two places having different emissivities of the surface to be measured are measured at two different auxiliary-heat-source temperatures, a reflectance ratio of the two places having the different emissivities is calculated on the basis of two measured radiances of the two places having the different emissivities, and temperature of the surface to be measured is obtained using reflectance ratio and measured radiances of the two places having different emissivities.
Abstract:
A system and method for calibrating an imaging system includes a shutter that is moveable in to the optical path of the imaging system to generate an image of the shutter surface, which is flat and uniform. The shutter can be moved in and out of the optical path between first and second positions. The shutter is heated whilst in the second position and then returned to the first position. Data sets generated at two different temperatures enable the image generated by the imaging system in normal use to be to be adjusted for responsivity and variation in DC offset of the specific pixel array.
Abstract:
A test apparatus for testing an IR sensor of train undercarriage temperatures is disclosed. The IR sensor may be used to obtain infrared IR emission data by sensing a wheel or a wheel bearing of a rail vehicle. The test apparatus may comprise a heat emitter for supplying IR emissions at a reference temperature to the IR sensor. A support may support the heat emitter at a position spaced from the passage of the rail vehicle and in an orientation for directing the IR emissions at the IR sensor.
Abstract:
A blackbody radiation device (110) includes a planar filament emission element (102) and a planar detector (104) for respectively producing and detecting radiation having width dl/l less than about 0.1 to test a sample gas, where l is the wavelength of the radiation; a reflector (108); a window (W); an electrical control (118); and a data output element (116).