| 摘要 |
PURPOSE:To simultaneously perform a logarithmic compression and a temperature compensation, by a method wherein a signal from a photoelectric element is inputted to a first logarithmic amplifier, a signal of a voltage generator controlled by a temperature measuring element is inputted to a second logarithmic amplifier, and each output value is added. CONSTITUTION:A signal from a photoelectric element 14, having non-linear properties, of a radiation thermometer is inputted to a first logarithmic amplifier 15, a voltage of a voltage generator 17, being capable of carrying a voltage by means of an output of a temperature measuring element Rh mounted in the proximity of the photoelectric element 14, is inputted to a second logarithmic 16 which has an equal function to that of the first logarithmic amplifier 15 and is connected in a symmetrical shape thereto, and the outputs of both the logarithmic amplifiers 15 and 16 are added to obtain a logarithmically compressed output. This prevents the exercising of the influence, produced due to a temperature drift of the photoelectric element 14, on an output voltage through erasing of a change due to temperature, and enables to simultaneously perform both a logarithmic compression and a temperature compensation through a simple circuit constitution. |
