Abstract:
A method of true temperature determination, including, (a) acquiring radiation emitted by an object at a plurality of wavelengths (50), (b) determining a characteristic of the acquired radiation which is based on a relationship between radiative emissions acquired at more than one wavelength (50), (c) determining a factor related to an error, using the characteristic (54) and calculating a current temperature of the object based on the correctional factor (56). Preferably, the factor is a vector of values indicating at least one emissivity value.
Abstract:
A method for evaluating the channel signals of a multichannel pyrometer, including the digital processing of the output signals of all the channels analyzed according to the thermal radiation law L = Ec1 [exp(c2 lambda /T)-1] , and including an error compensation procedure in order to evaluate the true temperature from the different values obtained in the different channels. During the error compensation procedure each radiance signal L is perturbed by subsequently addin random increments delta L comprised between zero and the estimated experimental error, the new temperature values and emissivities values are then evaluated with the respective uncertainties and finally the true temperature is selected therefrom in accordance with the degree of confidence of the new values.
Abstract:
The invention concerns a multi-wavelength pyrometer for the measurement of the temperature and emissivity of a surface above 900 K. The pyrometer has several radiation detectors sensitive in different wavebands μ1... μi... μn as well as a data processor to which the detector outputs are fed after digitalization and which calculates the temperature of the surface from these detector outputs using Wien-Planck's law, assuming the surface is a perfect black body. The emissivity is then calculated, as a function of the temperature and the wavelength, from these calculated temperature values using an approximation method, and from this, the required temperature. The invention calls for the differences between the actual pyrometer signals and the signals which would be expected from the assumed emissivity and the temperature calculated from this emissivity to be determined for various approximations and various wavelengths. The approximation which gives, for all the wavelengths, the least sum of the squares of these differences is then selected.
Abstract:
The invention relates to an apparatus for measuring the temperature of a body, comprising: a first laser light source for radiating the body with a laser light beam with a first wavelength such that the body undergoes a measurable temperature increase; a second laser light source for radiating the body with a laser light beam with a second wavelength such that the body undergoes a measurable temperature increase; a first radiation detector for detecting radiation of the first wavelength coming from the object; a second radiation detector for detecting radiation of the second wavelength coming from the object; a control circuit which is adapted to form time windows of the first type and of the second type, wherein the control device activates the first laser light source and the second radiation detector during windows of the first type and activates the second laser light source and the first radiation detector during windows of the second type, wherein the apparatus is adapted to measure the temperature of a body performing a periodic movement, wherein the control device is adapted to determine the time windows such that between the beginning of a time window of the first type and the beginning of a time window of the second type the body has travelled through at least a part of its periodic movement.
Abstract:
A method for measuring thermal differences in infrared emissions from semiconductors, the method utilizing an image sensor including an array detector having a plurality of detector elements which produce signals corresponding to semiconductor radiation emission focused thereupon by an optical lens system. At least one bandpass filter is utilized to substantially filter that portion of the semiconductor radiation emission having wavelengths greater than 5 micrometers. The detector element signals are processed to identify performance degrading phenomena occuring in the semiconductor device.
Abstract:
A scanning radiation sensor provides a dual spectral infrared measurement scheme that is capable of providing contactless temperature measurements from a plurality of points along a scan line of a target surface area without knowing the emissivity of the target surface. The sensor is capable of correcting for changes in the emissivity of the target due to varying surface conditions. The dual spectral line scanning infrared sensor determines the radiation from each of a plurality of spots along a scan line on a target, and produces an average radiation from the plurality of spots, and converts the average radiation to a representation of temperature of the target.