Abstract: An infrared window includes a substrate composed of “KRS-5” as a raw material which is mixed crystal of thallium iodide and thallium bromide and an infrared transmissive coating that covers a surface of the substrate. A raw material for the infrared transmissive coating is parylene. A thickness of the infrared transmissive coating is set to a value at which an infrared absorptance is lower than 3%. The thickness of the infrared transmissive coating is set to a value at which the infrared absorptance is lower than 3%. The thickness of the infrared transmissive coating is set to a value within a range not smaller than 20 nanometers and smaller than 50 nanometers.

Abstract: A beam splitter assembly includes a beam splitter, a holder that holds the beam splitter, and a first spacer group arranged between the beam splitter and the holder. The first spacer group includes three first spacer pieces. Each of the three first spacer pieces includes a first optical element holder and a first positioning portion. The holder includes three first spacer piece acceptance recesses. Each of the first spacer piece acceptance recesses is in a shape corresponding to the first positioning portion. The three first spacer pieces are accommodated in the three first spacer piece acceptance recesses, respectively. The first optical element holder of each of the three first spacer pieces abuts on the beam splitter.

Abstract: In an FTIR 1, a beam splitter 12, fixed mirror 13 and movable mirror 14 are shared by a main interferometer 10 including a multiwavelength infrared light source 11 and a control interferometer 20 including a semiconductor laser 21. A first detector 16 detects infrared interference light generated by the main interferometer 10 and transmitted through or reflected by a sample. A second detector 26 detects monochromatic interference light generated by the control interferometer 20. A spectrum creator 32 determines an optical path difference between an optical path via the fixed mirror 13 and an optical path via the movable mirror 14, based on the intensity and uncalibrated oscillation wavelength of the monochromatic interference light detected by the second detector 26, and creates a spectrum by performing fast Fourier transform on an interferogram which shows a distribution of the intensity of the infrared interference light detected by the first detector 16 with respect to the optical path difference.

Abstract: An infrared spectrophotometer uses a configuration that allows notification of the appropriate replacement time for an electric heater. The infrared spectrophotometer is provided with an electric heater 1, a PWM control circuit 5, a state detection unit 61, and a notification processing unit 62. The electric heater 1 is a light source that irradiates infrared radiation. The PWM control circuit 5 carries out PWM control so that the current supplied to the electric heater 1 is constant. The state detection unit 61 detects the state of the electric heater 1 on the basis of the variation in the duty cycle during PWM control. The notification processing unit 62 reports the result of the detection by the state detection unit 61.

Abstract: An infrared spectrophotometer uses a configuration that allows notification of the appropriate replacement time for an electric heater. The infrared spectrophotometer is provided with an electric heater 1, a PWM control circuit 5, a state detection unit 61, and a notification processing unit 62. The electric heater 1 is a light source that irradiates infrared radiation. The PWM control circuit 5 carries out PWM control so that the current supplied to the electric heater 1 is constant. The state detection unit 61 detects the state of the electric heater 1 on the basis of the variation in the duty cycle during PWM control. The notification processing unit 62 reports the result of the detection by the state detection unit 61.

Abstract: A beam splitter assembly includes a beam splitter, a holder that holds the beam splitter, and a first spacer group arranged between the beam splitter and the holder. The first spacer group includes three first spacer pieces. Each of the three first spacer pieces includes a first optical element holder and a first positioning portion. The holder includes three first spacer piece acceptance recesses. Each of the first spacer piece acceptance recesses is in a shape corresponding to the first positioning portion. The three first spacer pieces are accommodated in the three first spacer piece acceptance recesses, respectively. The first optical element holder of each of the three first spacer pieces abuts on the beam splitter.

Abstract: In an FTIR 1, a beam splitter 12, fixed mirror 13 and movable mirror 14 are shared by a main interferometer 10 including a multiwavelength infrared light source 11 and a control interferometer 20 including a semiconductor laser 21. A first detector 16 detects infrared interference light generated by the main interferometer 10 and transmitted through or reflected by a sample. A second detector 26 detects monochromatic interference light generated by the control interferometer 20. A spectrum creator 32 determines an optical path difference between an optical path via the fixed mirror 13 and an optical path via the movable mirror 14, based on the intensity and uncalibrated oscillation wavelength of the monochromatic interference light detected by the second detector 26, and creates a spectrum by performing fast Fourier transform on an interferogram which shows a distribution of the intensity of the infrared interference light detected by the first detector 16 with respect to the optical path difference.

Abstract: The Fourier transform infrared spectrophotometer includes: a light source 11 for generating infrared light having a wavelength width including an absorption wavelength of a compound to be analyzed; an interferometer including a fixed mirror 15 and a movable mirror 16, for generating interfering light from the infrared light; a detector 25 for generating a voltage with a magnitude corresponding to the intensity of the interfering light, and for outputting a voltage obtained by subtracting, from the aforementioned voltage, a voltage with a predetermined magnitude; a high-pass filter 464 for allowing the passage of frequency components equal to or higher than a predetermined frequency in an output voltage from the detector 25; an amplifier 463 for amplifying an output voltage from the high-pass filter 464 by a predetermined multiplying factor; and an analogue-to-digital converter 27 for converting an output voltage from the amplifier 463 into a digital signal.

Abstract: The Fourier transform infrared spectrophotometer includes: a light source 11 for generating infrared light having a wavelength width including an absorption wavelength of a compound to be analyzed; an interferometer including a fixed mirror 15 and a movable mirror 16, for generating interfering light from the infrared light; a detector 25 for generating a voltage with a magnitude corresponding to the intensity of the interfering light, and for outputting a voltage obtained by subtracting, from the aforementioned voltage, a voltage with a predetermined magnitude; a high-pass filter 464 for allowing the passage of frequency components equal to or higher than a predetermined frequency in an output voltage from the detector 25; an amplifier 463 for amplifying an output voltage from the high-pass filter 464 by a predetermined multiplying factor; and an analogue-to-digital converter 27 for converting an output voltage from the amplifier 463 into a digital signal.