JPH0240515A - Light source for infrared-ray spectroscope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an infrared spectrometer, particularly a versatile Fourier transform infrared spectrophotometry bag f (FT-IR) or an infrared interference spectrophotometer. Concerning a measuring device. The present invention also relates to a blackbody furnace, that is, a cavity radiator, for a light source used in an infrared spectrophotometer, and in particular, for a light source of a Fourier transform infrared spectrophotometer or an infrared interference spectrophotometer, which is highly versatile. Regarding a blackbody furnace with a large exit area.

(b) Conventional technology Fourier transform infrared spectrophotometers include total reflection absorption measurement method, diffuse reflection measurement method, high-sensitivity reflectance measurement method, photoacoustic spectroscopy, infrared emission method, trace amount micro sample measurement method, and gas chromatography. It is used for various measurement applications, such as in combination with high-performance liquid chromatography methods or high-performance liquid chromatography methods.

However, the light sources for conventional Fourier transform infrared spectrophotometers include a nichrome wire, a Grover light source that uses a silicon carbide rod, and a Nernst light source that combines zirconium oxide with rare earth oxides such as yttrium, thorium, and erbium. and high-pressure mercury lamps are used.

(c) Problems to be solved by the invention However, these light sources used in conventional Fourier transform infrared spectrophotometers have low brightness because the temperature cannot be raised, and there is also absorption due to the characteristics of the heater. Therefore, it cannot be used for many such purposes and is considered a problem.

Therefore, a spiral groove is formed around a rod-shaped body of a high melting point ceramic material such as alumina, zirconia, or magnesia, and a metal wire such as platinum is wound along this groove, and a cylindrical-conical shape with an opening at the end is formed. A small blackbody furnace has been proposed in which a cavity is formed in the direction of its internal axis (for example, U.S. Pat.
, 499, 382).

However, although such a small blackbody furnace can be expected to produce high brightness, it cannot be used as a light source for a general-purpose Fourier transform infrared spectrophotometer because the size of the sample chamber is limited. This is a problem.

The present invention aims to solve problems related to the brightness of the light source of the conventional Fourier transform infrared spectrophotometer and its versatility.

(2) Means for Solving the Problems The present invention enables a general-purpose Fourier transform infrared spectrophotometer to be used as an infrared light source with stable and high emissivity over the entire wavenumber range in which it is used. The purpose of the present invention is to provide an infrared spectrometer such as a general-purpose Fourier transform infrared spectrophotometer equipped with a blackbody furnace that can be used.

That is, in the present invention, a cylindrical reactor core having an open conical recess formed at one end is wound around its side surface in a spiral manner by a band-shaped resistance heating heating element, and the heating element A light source for an infrared spectrometer is characterized in that the outside of the body is surrounded by a heat insulating layer and formed into a blackbody furnace.

In the present invention, the core of the blackbody reactor is preferably formed of a ceramic material with a high melting point such as alumina, zirconia, or magnesia, or other external radiation emitters, since high brightness can be obtained. To heat nichrome, chromium-A1, Cr-Fe-A
A strip-shaped heating element made of a resistance heating material such as I, silicon carbide, platinum, or platinum-rhodium is used. However, a band-shaped silicon carbide heating element is preferable because it is stable in the air and can easily reach a high temperature. The band-shaped heating element is
It is wound spirally in contact with the outer surface of the core. in this case,
In the present invention, it is preferable to wrap the band-shaped heating element around the reactor core in a double helical manner, since the connecting terminal can be arranged at the end opposite to the radiation surface of the core, and the heating density can be increased. To prevent heat from the heating element from escaping to the outside,
Preferably covered with insulation.

In the present invention, the reactor core includes:
A cavity is formed by opening at the end.

In this case, if the cavity formed at the end is formed in the shape of a concave cone, the radiant beams will be formed in parallel.

This cavity is preferably formed by appropriately selecting the depth of the cavity and the radius of the opening of the cavity, or by blackening the inner surface of the cavity so that a high emissivity and radiant flux can be easily obtained. In the blackbody reactor according to the present invention, the radiation intensity is determined by the temperature of the core, so a temperature sensor is provided in the core to control the temperature of the core so that the radiation intensity is constant. It is preferable to form.

(E) Function In the present invention, a conical recess is formed at one end of the columnar shape, and a belt-shaped heating element for resistance heating is wound spirally around the side surface of the conical recess to form the core of the blackbody furnace. Since the light source for the Fourier transform infrared spectrophotometer was used as the light source for the Fourier transform infrared spectrophotometer, a large luminous body with high brightness and uniform high emissivity across the entire wavenumber range was used as the light source for the Fourier transform infrared spectrophotometer. It can be done. Therefore, it can be used as a light source for general-purpose Fourier transform infrared spectroscopy with a large sample chamber.

(F) EXAMPLES Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited in any way by the following explanations and examples.

FIG. 1 is a schematic partial side sectional view of a blackbody furnace portion of a light source in an embodiment of the present invention.

In this example, the blackbody reactor 1 has a cylindrical body made of alumina as the core 2. A conical hole 4 is formed in the radiation side end 3 of the core 2. is 4 ms in diameter. A band-shaped heating element 5 made of silicon carbide is wound around the side surface 7 of the furnace JC 12 in a double spiral.

The band-shaped silicon carbide heating element 5 used in this example is
For example, if the outer diameter of the furnace IC 12 is 10 rings and the diameter of the hole 4 is 6--, the spiral body of the band-shaped silicon carbide heating element has an outer diameter of 25 mm or less and a length of 70 m+.
It is less than or equal to e. The band-shaped silicon carbide heating elements 5 are fixed to the side surface 7 of the core 2 by heat-resistant cement 6 for electrical insulation filled between them for electrical insulation. Both ends 8 of this band-shaped silicon carbide heating element 5
and 9 are provided with terminals 10 and 11, respectively,
Conductive wires 12 and 13 are electrically connected to the terminals 10 and 11.

In this example, in order to prevent heat loss from the blackbody furnace 1, a cylindrical heat insulating material 14 is provided surrounding the band-shaped silicon carbide heating element 5.

The blackbody furnace of this example is configured as described above, so when a switch (not shown) is turned on and electricity is passed through the silicon carbide heating element 5 to generate heat, the reactor core 2 is heated.
The reactor core 2 is heated to a high temperature, and from the surface of the hole on the radiation side 3,
It has a high uniform emissivity over the entire range of infrared wavenumbers and can emit infrared rays with high brightness.

The blackbody furnace 1 of this example was housed in a container (not shown) equipped with a cooling coil and the like, and was used as a light source for an infrared spectrophotometer.

In this way, the Fourier transform infrared spectrophotometer using the blackbody furnace 1 of this example as a light source can be used with total internal reflection absorption measurement, diffuse reflectance measurement, high-sensitivity reflectance measurement, photoacoustic spectroscopy, and luminescence measurement. Good results were obtained when used in measurements such as the micro sample measurement method and the micro sample measurement method. Similarly, good results were also obtained when the blackbody furnace 1 of this example was combined with a gas chromatography separation device or a high-performance liquid chromatography separation device.

In this example, the heating element 5 and the reactor core 2 are in direct contact, but in order to improve heat conduction, heat-resistant cement is used to connect the reactor core 2 with heat-resistant cement, as in conventional blackbody reactors. The space between the heating elements 5 can be fixed. Similarly, in order to keep the temperature of the reactor core 2 constant, a temperature sensor is provided inside the reactor core 2,
Temperature control can be made possible. By blackening the inner surface of the hole 4 in the core 2 to increase the absorption rate, the number of necessary reflections will be reduced and the size of the opening can be made relatively large, thereby improving the infrared emissivity. Can be done.

In this example, the core is made of alumina, but it can be similarly made of other high melting point zirconia, magnesia, or other external radiation emitters.

(g) Effects of the invention In the present invention, a conical recess is formed at one end of a columnar ceramic body, and a band-shaped resistance heating heating element is wound spirally around the side surface of the conical recess to form the core of a blackbody furnace. The light source of the present invention has the following properties:
Compared to the light source of conventional infrared spectrophotometer measurement equipment, it can be a large light source with high brightness, and also has a high emissivity in the infrared wavenumber range used and has small fluctuations in light intensity. Therefore, highly accurate Fourier transform infrared spectrophotometry can be performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic partial side sectional view of a blackbody furnace portion of a light source in an embodiment of the present invention. Regarding the symbols in the figure, 1 is the black body furnace, 2 is the core, 3 is the radiation side end, 4 is the hole, 5 is the band-shaped silicon carbide heating element, 6 is the heat-resistant cement, 7 is the side of the core, 8 and 9 is the end of the resistance heating element, 10 and 11 are terminals, 12 and 13 are conductive wires, 1
4 is a heat insulating material.

Claims (1)

[Claims] A cylindrical reactor core is formed with an open conical recess at one end, and the side surface of the core is spirally wrapped around a band-shaped heating element for resistance heating. A light source for an infrared spectrometer, characterized in that it is surrounded by a heat insulating layer and formed in a blackbody furnace.