The invention relates to a method for estimating drift in a solar radiation sensor (2) and for calibrating such a sensor, in which the radiation (G.sub.MES) measured by this sensor under its conditions of use and a radiation model (51) are taken into account.

An earphone includes an audio transmitter, a housing, a sound passage pipe, a radiator, and a light receiver. The audio transmitter transmits sound. The housing has an internal space for containing the audio transmitter. The sound passage pipe guides sound produced at the audio transmitter into an external auditory canal. The radiator radiates light into the external auditory canal. The light receiver is disposed in the internal space of the housing. The light receiver converts the light into a signal, the light having been reflected off the external auditory canal and passed through an internal space of the sound passage pipe. The housing, the sound passage pipe, and the radiator are disposed in this order.

The present invitation relates to an optical radiation measurement method based on light filter units, comprising the steps of: 1) providing characteristic filter units and correction light filter units in front of detection units to obtain multiple measured response values of an object to be detected; and, 2) selecting one or more sampling regions within a waveband to be detected, and calculating, according to a corresponding simultaneous expression/equation system of the measured response values, a spectral power distribution within the waveband to be detected. In this method, by introducing a small number of correction light filter units, the spectral power distribution within the entire waveband to be detected can be obtained without using a large number of narrow waveband color filters. In addition, a light radiation measurement apparatus is disclosed.

The present invitation relates to an optical radiation measurement method based on light filter units, comprising the steps of: 1) providing characteristic filter units and correction light filter units in front of detection units to obtain multiple measured response values of an object to be detected; and, 2) selecting one or more sampling regions within a waveband to be detected, and calculating, according to a corresponding simultaneous expression/equation system of the measured response values, a spectral power distribution within the waveband to be detected. In this method, by introducing a small number of correction light filter units, the spectral power distribution within the entire waveband to be detected can be obtained without using a large number of narrow waveband color filters. In addition, a light radiation measurement apparatus is disclosed.

An approach for controlling ultraviolet intensity over a surface of a light sensitive object is described. Aspects involve using ultraviolet radiation with a wavelength range that includes ultraviolet-A and ultraviolet-B radiation to irradiate the surface. Light sensors measure light intensity at the surface, wherein each sensor measures light intensity in a wavelength range that corresponds to a wavelength range emitted from at least one of the sources. A controller controls the light intensity over the surface by adjusting the power of the sources as a function of the light intensity measurements. The controller uses the light intensity measurements to determine whether each source is illuminating the surface with an intensity that is within an acceptable variation with a predetermined intensity value targeted for the surface. The controller adjusts the power of the sources as a function of the variation to ensure an optimal distribution of light intensity over the surface.

An approach for controlling ultraviolet intensity over a surface of a light sensitive object is described. Aspects involve using ultraviolet radiation with a wavelength range that includes ultraviolet-A and ultraviolet-B radiation to irradiate the surface. Light sensors measure light intensity at the surface, wherein each sensor measures light intensity in a wavelength range that corresponds to a wavelength range emitted from at least one of the sources. A controller controls the light intensity over the surface by adjusting the power of the sources as a function of the light intensity measurements. The controller uses the light intensity measurements to determine whether each source is illuminating the surface with an intensity that is within an acceptable variation with a predetermined intensity value targeted for the surface. The controller adjusts the power of the sources as a function of the variation to ensure an optimal distribution of light intensity over the surface.

An optical power monitoring device that monitors power of input light reflected back into an optical fiber among output light output from the optical fiber, the optical power monitoring device includes: a photodetector disposed by the optical fiber that detects Rayleigh scattered light generated by the input light and the output light that are guided by the optical fiber; and a calculator that performs a calculation to exclude a component that corresponds to an output of the output light detected by the photodetector using first information that indicates a relationship between an output of the output light obtained in advance under a condition where the output light is not reflected and the output of the output light detected by the photodetector.

An earphone includes an audio transmitter, a housing, a sound passage pipe, a radiator, and a light receiver. The audio transmitter transmits sound. The housing has an internal space for containing the audio transmitter. The sound passage pipe guides sound produced at the audio transmitter into an external auditory canal. The radiator radiates light into the external auditory canal. The light receiver is disposed in the internal space of the housing. The light receiver converts the light into a signal, the light having been reflected off the external auditory canal and passed through an internal space of the sound passage pipe. The housing, the sound passage pipe, and the radiator are disposed in this order.

A sensor arrangement comprises at least a first, a second, and a third light sensor. A three-dimensional framework comprises at least a first, a second, and a third connection means which are connected to the at least first, second, and third light sensor, respectively. The first, the second, and the third connection means are configured to align the at least first, second, and third light sensor along a first, second, and third face of a polyhedron-like volume, respectively, such that the sensor arrangement encloses the polyhedron-like volume. The invention also relates to a method for operating the sensor arrangement.

A sensor arrangement comprises at least a first, a second, and a third light sensor. A three-dimensional framework comprises at least a first, a second, and a third connection means which are connected to the at least first, second, and third light sensor, respectively. The first, the second, and the third connection means are configured to align the at least first, second, and third light sensor along a first, second, and third face of a polyhedron-like volume, respectively, such that the sensor arrangement encloses the polyhedron-like volume. The invention also relates to a method for operating the sensor arrangement.