JP2012037458A - Sample holder for liquid oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sample holder for liquid oil for performing spectroscopic measurement of liquid oil that can maintain high analysis accuracy even with a smaller amount of liquid oil.
A basement member (2) including a plate-like basement member (2) and a fixing plate (3), and a fixture (8) for holding a fixed state in which they are attached together. And through holes (2c, 3c) as light transmission windows that vertically penetrate the fixing plate (3), and the basement member (2) has a peripheral portion of the through holes (2c) extending from the main surface to a predetermined depth. A counterbore part (2d) that is counterbored to the end is provided, and two plate-like optical crystal plates (6, 4) are sequentially stacked in the counterbore part so as to close the through hole (2c), An elastic member (7) for bringing the optical crystal plates (4, 6) into close contact with each other is provided along the peripheral edge of the through hole (3c) on the main surface of the fixed plate (3) so as not to interfere with at least the light transmission window. A spacer member (5) is inserted between the optical crystal plates (4, 6), and liquid oil (9 ).
[Selection] Figure 3

Description

  The present invention relates to a sample holder for liquid oil that is set in an infrared spectrometer and performs spectroscopic measurement of liquid oil.

  Infrared spectroscopic analysis is an analysis method in which a measurement substance is irradiated with infrared rays and a chemical bond of the measurement substance is identified from the spectrum of transmitted or reflected light. Here, when the measurement substance is a liquid substance, the liquid substance is stored in a container containing an infrared transmission substance, and this is set at a position crossing the infrared path in the infrared spectroscopic measurement apparatus and analyzed with the transmitted light. On the other hand, in order to analyze a measurement substance made of a small amount of liquid substance, the liquid substance was dropped on an optical crystal plate made of an infrared transmitting substance, and the analysis was performed with transmitted light. However, the thickness of the infrared transmitting portion cannot be made uniform due to the surface tension of the liquid substance, and it has been difficult to perform quantitative analysis. On the other hand, an analysis method is known in which a liquid substance as a measurement substance is poured between two optical crystal plates arranged in parallel at a predetermined interval.

  In Patent Document 1, a natural substance such as cellulose or a synthetic fiber such as polyester absorbs a liquid substance as a measurement substance, and the liquid substance is leached by sandwiching the fiber between two optical crystal plates. A method for performing spectroscopic analysis is disclosed. Even in a small amount, the thickness of the liquid material in the infrared transmission portion, that is, the infrared transmission length, is equal to the distance between the two optical crystal plates, and can be made uniform.

  Further, in Patent Document 2, an enclosure having a notch made of silicon oxide for holding a liquid substance is formed at a uniform height on at least one of two optical crystal plates (window plates) made of silicon single crystal. It is disclosed that an optical crystal plate (window plate) is sandwiched between plates. By adjusting the thickness of the enclosure, the distance between the two optical crystal plates can be kept constant and parallel, and the infrared transmission length of the liquid material can be made uniform.

JP-A-2005-030990 Japanese Utility Model Publication No. 03-16047

  By the way, in the infrared spectroscopic analysis of liquid oil, chemical bonds such as additives added in a small amount are difficult to distinguish clearly from the chemical bonds of the main hydrocarbons of liquid oil. Therefore, it is required to increase the distance between the two optical crystal plates and extend the infrared transmission length to clarify the spectrum. On the other hand, to analyze a smaller amount of liquid oil, the infrared transmission area is reduced. In such a case, for example, by reducing the area of the liquid oil holding portion surrounded by the enclosure with respect to the area of the optical crystal plate as in Patent Document 2, the infrared transmission area can be reduced. However, it is difficult to keep the distance between the two optical crystal plates constant and parallel in such a small enclosure, and the transmission length of the infrared rays of the liquid substance cannot be made uniform. That is, it is difficult to perform a quantitative analysis.

  The present invention has been made in view of such circumstances, and the object of the present invention is to perform spectroscopic measurement of liquid oil set in an infrared spectrometer capable of maintaining high analysis accuracy even with a smaller amount of liquid oil. Providing a sample holder for liquid oil to perform.

  A sample holder for liquid oil according to the present invention is a sample holder that is set in an infrared spectrometer and performs spectroscopic measurement of liquid oil, and has plate-like shapes each having first and second main surfaces parallel to each other. A basement member and a fixing plate, and a fixture for holding a fixing state in which the first main surfaces of the basement member and the fixing plate are attached to each other, and the basement member and the fixing plate are vertically arranged in the fixing state. The basement member is provided with a through hole serving as a light transmission window that passes through the basement member, and a peripheral edge of the through hole is spotted from the first main surface to a predetermined depth along the axis of the through hole. A counterbore portion is provided, and two plate-like optical crystal plates are sequentially stacked in the counterbore portion so as to close the through hole, and the fixing plate is fixed to the basement member with the fixing tool. Together with An elastic member for bringing the optical crystal plates into close contact with each other is provided along a peripheral edge of the through hole on the first main surface of the fixed plate, and at least a spacer between the optical crystal plates so as not to interfere with the light transmission window. A member is inserted to hold the liquid oil in the gap.

  According to this invention, the plate-like basement member having the first and second main surfaces parallel to each other and the fixing plate are fixed by the fixing tool, so that the basement member is inserted through the elastic member. The counterbore part and the fixing plate can press and fix the two optical crystal plates holding the liquid oil and the spacer member sandwiched therebetween. Since the basement member having a large area relative to the optical crystal plate and the main surface of the fixing plate can be attached in parallel to each other, the main surfaces of the two optical crystal plates reduce the amount of liquid oil, Even if the transmission area is reduced, it can be kept parallel. Therefore, the infrared ray transmission length of the liquid substance can be made uniform, and quantitative analysis can be performed. That is, it is possible to obtain a liquid oil sample holder for an infrared spectroscopic measurement apparatus capable of performing spectroscopic measurement while maintaining high analysis accuracy even with a smaller amount of liquid oil.

  In the above-described invention, the light transmission window may be circular. According to this invention, since the infrared light passing through the light transmission window transmits liquid oil uniformly in all directions from the irradiation axis, high analysis accuracy can be maintained even in analysis of a smaller amount of liquid oil.

  In the above-described invention, the optical crystal plate may be a quadrangle. According to this invention, it is difficult for the optical crystal plate to be displaced in the spot facing portion, and high analysis accuracy can be maintained even in the analysis of a smaller amount of liquid oil. Moreover, handling of the optical crystal plate is facilitated, and high analysis accuracy can be maintained without causing a decrease in analysis accuracy due to surface damage of the optical crystal plate.

  In the above-described invention, the spacer member may be an annular plate that surrounds the through hole. According to this invention, the infrared light is not blocked, the irradiation area of the infrared liquid oil is not reduced, and the intensity of the obtained spectral spectrum is not lowered. It can be kept high.

FIG. 3 is a component diagram of one embodiment of the present invention. It is a perspective view at the time of the assembly of one Example of this invention. It is sectional drawing at the time of the assembly of one Example of this invention. 1 is a block diagram of an apparatus including one embodiment of the present invention. FIG. 3 is a spectrum obtained by one embodiment of the present invention. It is a figure of the spectrum obtained by one Example of this invention, and a prior art example.

  The sample holder according to one embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1, the sample holder 1 is a holder that can assemble and hold liquid oil as a measurement substance, and includes a basement member 2, a fixing plate 3, an upper window plate 4, a spacer member 5, A lower window plate 6 and an elastic member 7 are included.

  The basement member 2 is a plate whose main surface is rectangular, and the basement member surface 2a and the basement member back surface 2b, which are the main surfaces, are parallel to each other. Further, the basement member 2 has a substantially cylindrical inner peripheral surface that penetrates substantially perpendicularly to the main surface, and allows infrared rays irradiated in the infrared spectrometer 10 to pass through as will be described later. A basement member hole 2c is provided as a possible window. A counterbore process is performed along the axis of the basement member hole 2c, that is, the upper surface around the basement member hole 2c is cut smoothly into a circle. The substantially cylindrical inner peripheral surface and bottom surface (surface connected from the upper end of the basement member hole 2c) generated by the counterbore processing are defined as a counterbore portion 2d. On the basement member surface 2a, the four bolts 2e use the axis of the basement member surface 2a at a predetermined interval from the counterbore 2d, that is, at a position corresponding to a bolt hole 3d of the fixing plate 3 described later. They are planted so as to be substantially perpendicular to each other.

  The fixed plate 3 is a plate body whose main surface is rectangular, and the fixed plate front surface 3a and the fixed plate back surface 3b, which are the main surfaces, are parallel to each other. The fixing plate 3 is provided with a fixing plate hole 3c and four bolt holes 3d as holes that penetrate perpendicularly to the main surface. The fixed plate hole 3c is provided at a position corresponding to the basement member hole 2c at the substantially center of the fixed plate 3 as a circular window through which infrared rays can pass. The diameters of the openings of the basement member hole 2c and the fixed plate hole 3c are the same. The bolt holes 3d are provided at positions corresponding to the above-described bolts 2e at a predetermined interval from the fixing plate hole 3c. At the time of assembly described later, the basement member 2 and the fixing plate 3 can be fastened by passing the bolt 2e through the bolt hole 3d and tightening with the nut 8 (see FIG. 2).

The upper window plate 4 and the lower window plate 6 are plate bodies made of potassium bromide (KBr) and having a substantially rectangular parallelepiped shape. The lower window plate 6 has a lower window plate upper surface 6a. In this embodiment, potassium bromide was used as the material of the upper window plate 4 and the lower window plate 6, but in general, infrared rays in the infrared wave number range (4000 to 400 cm ⁻¹ ) irradiated by infrared spectroscopy. For example, an optical crystal capable of transmitting light, such as sodium chloride (NaCl), zinc selenide (ZnSe), thallium bromoiodide (KRS-5), cesium iodide (CsI), or the like may be used.

  Referring to FIG. 1 together with FIG. 3, the spacer member 5 is an annular plate body made of a material containing lead, and has an inner peripheral surface 5a. The spacer member 5 is disposed between the upper window plate 4 and the lower window plate 6 in the sample holder 1 so as to surround a columnar region 9a sandwiched between the basement member hole 2c and the fixing plate hole 3c. When infrared rays are irradiated from above the fixing plate 3 substantially perpendicularly to the fixing plate surface 3a, the infrared rays pass through the fixing plate hole 3c, the region 9a, and the basement member hole 2c. In this embodiment, a material containing lead is used as the material of the spacer member 5, but it has a mechanical strength that does not deform even if it is sandwiched between two optical crystal plates, and is in contact with liquid oil. Alternatively, a substance that keeps chemical stability, for example, a material containing aluminum may be used.

  The elastic member 7 is made of rubber having elasticity and is an annular plate. The elastic member 7 is bonded to the fixed plate rear surface 3b side so as to surround the fixed plate hole 3c. In the present embodiment, the shape of the elastic member 7 is a ring-shaped plate, but the shape of the outer peripheral side is not particularly limited as long as the shape of the annular inner periphery is circular. The nut 8 can be screwed to the bolt 2 to fasten the basement member 2 and the fixing plate 3.

  Here, as shown in FIG. 4, as an example, the infrared spectrometer 10 includes a light source 11, an interferometer 12, a sample chamber 13, a detector 14, an A / D converter 15, and a computer. 16 and a display 17. The light source 11 is a high-intensity ceramic light source and can emit infrared rays.

  Interferometer 12 includes a fixed mirror 12a, a movable mirror 12b, and a semi-transmissive mirror 12c. Both the fixed mirror 12a and the movable mirror 12b are reflecting mirrors. The semi-transmissive mirror 12c can reflect a part of the irradiated light and transmit the other remaining part of the light.

  The sample chamber 13 is provided to irradiate the liquid oil 9 held in the sample holder 1 with infrared rays that cause interference due to the movement of the movable mirror 12b. Therefore, the sample chamber 13 irradiates the infrared rays from above substantially perpendicularly to the fixed plate surface 3a, passes through the basement member hole 2c and the solid plate hole 3c, and allows the liquid oil 9 to pass through. In addition, the sample holder 1 can be set.

  The detector 14 can detect infrared light transmitted through the liquid oil 9, generate an analog electrical signal corresponding to the absorbance of the received infrared light, and output the analog electrical signal to the A / D converter 15. The A / D converter 15 can convert the analog electrical signal output from the detector 14 into a digital electrical signal and output it to the computer 16. The computer 16 includes an arithmetic processing unit and a storage device such as a memory. The computer 16 can obtain a spectral spectrum by performing a fast Fourier transform on the digital electrical signal output from the A / D converter 15. The display 17 is a liquid crystal display, and the spectrum obtained by the computer 16 can be visualized and confirmed by the operator. The display 17 may be another output device such as a projector or a printer.

  Next, how to assemble the sample holder 1 will be described with reference to FIGS. 1 to 3.

  As shown in FIGS. 1 to 3, the spacer member 5 is first placed on the lower window plate 6. Liquid oil 9 is dripped so that the area | region formed with the lower window board upper surface 6a of the lower window board 6 and the internal peripheral surface 5a of the spacer member 5 may be satisfy | filled. The upper window plate 4 is placed thereon, and the liquid oil 9 is sandwiched between the upper window plate 4, the lower window plate 6, and the spacer member 5. With the lower window plate 6, the spacer member 5, and the upper window plate 4 stacked in order from the bottom, these are placed on the bottom surface of the spot facing portion 2d. The fixing plate 3 is fastened to the basement member 2 with a nut 8 so that the upper window plate 4 is pressed toward the bottom surface of the spot facing portion 2d by the elastic member 7 bonded to the fixing plate back surface 3b side. Thereby, the liquid oil 9 as the measurement substance is held by the sample holder 1 between the upper window plate 4 and the lower window plate 6, surrounded by the spacer member 5.

  Here, the spacer member 5 and the elastic member 7 are installed so as to surround a region 9a that becomes a path of infrared rays. If the spacer member 5 and the elastic member 7 are installed in this way, the intensity of the obtained spectral spectrum is not reduced without blocking the passage of infrared rays. Can be maintained.

  Next, the spectral spectrum of the liquid oil 9 obtained by the sample holder 1 according to the present embodiment will be described. The liquid oil 9 was a lubricating oil obtained by adding an additive to a hydrocarbon.

FIG. 5 shows a spectrum obtained by the sample holder 1 according to this example. The film thickness of the liquid oil 9 serving as the infrared transmission length is 0.025 mm, 0.05 mm, and 0.1 mm by the spacer member 5 in order from FIG. In any case, the spectrum derived from the hydrocarbon is clearly observed, and the base (base line) becomes undulated as the film thickness increases. On the other hand, the peak of a spectral spectrum derived from an additive having a wave number of about 1800 to 500 cm ⁻¹ is unclear when the film thickness is 0.025 mm and 0.05 mm, but becomes clear when the film thickness is 0.1 mm. When the film thickness is made thicker than 0.1 mm, noise increases. For example, the absorption of the peak representing the absorption characteristics of the hydrocarbon, which is a base oil near the wave number of 720 cm ^−1, becomes stronger, and the peak representing the absorption characteristics of the additive becomes unclear again. That is, for this liquid oil 9, it is appropriate to analyze the spectrum obtained with a film thickness of 0.1 mm.

  FIG. 6 shows a spectrum obtained by setting the film thickness of the liquid oil 9 to 0.1 mm. 6A is a spectral spectrum obtained using the sample holder 1 according to the present embodiment, and FIG. 6B is obtained using a conventional sample holder, that is, a wide sample oil holding region. It is the spectrum as a comparative example. Comparing these, even in the sample holder 1 according to the present embodiment in which the region where the liquid oil 9 is held is made narrower than that of the conventional type and a smaller amount of liquid oil is held, the strength is equivalent to that of the conventional type sample holder. A spectrum can be obtained. That is, the sample holder 1 according to the present embodiment can continuously perform quantitative analysis on the past analysis results obtained by the conventional holder.

  As described above, according to the present embodiment, the plate-like basement member 2 and the fixing plate 3 having main surfaces parallel to each other are fastened and fixed by the bolts 2e and the nuts 8 to thereby fix the elastic member 7. The spacer member 5 is sandwiched between the upper window plate 4 and the lower window plate 6 that hold liquid oil by the counterbore 2d of the basement member 2 and the fixing plate back surface 3b of the fixing plate 3. And can be fixed. Thereby, since the basement member 2 and the fixing plate 3 having a large area with respect to the upper window plate 4 and the lower window plate 6 can be attached to the basement member surface 2a and the fixing plate back surface 3b in parallel with each other, The main surfaces of the upper window plate 4 and the lower window plate 6 can be maintained in parallel even if the amount of the liquid oil 9 is reduced and the infrared transmission area is reduced. Therefore, the infrared transmission length of the liquid oil 9 can be made uniform, and quantitative analysis can be performed.

  Further, the basement member hole 2c and the fixing plate hole 3c are circular windows that allow infrared rays to pass through. Therefore, the infrared rays that pass through them are transmitted uniformly through the liquid oil in all directions from the irradiation axis. Accordingly, high analysis accuracy can be maintained even when analyzing a smaller amount of liquid oil 9.

  Furthermore, since the upper window plate 4 and the lower window plate 6 are quadrangular (substantially rectangular parallelepiped shape), for example, the position shift in the spot facing portion 2d can be suppressed by bringing the four corners into contact with the periphery. Therefore, high analysis accuracy can be maintained even when analyzing a smaller amount of liquid oil. Further, the upper window plate 4 and the lower window plate 6 which are quadrilaterals are easy to manufacture and easy to handle, and are difficult to cause surface damage due to handling mistakes. Therefore, it is possible to prevent a decrease in analysis accuracy due to surface damage of the upper window plate 4 and the lower window plate 6 and maintain high analysis accuracy.

  Although the exemplary embodiments according to the present invention have been described so far, the present invention is not necessarily limited thereto. Those skilled in the art will recognize a variety of alternative embodiments and modifications without departing from the scope of the appended claims.

1 Sample holder 2 Basement member 3 Fixed plate 4 Upper window plate 5 Spacer member 6 Lower window plate 7 Elastic member 9 Liquid oil

Claims (4)

A sample holder that is set in an infrared spectrometer and performs spectroscopic measurement of liquid oil,
A plate-like basement member and a fixing plate each having first and second main surfaces parallel to each other; and a fixture for holding a fixed state in which the first main surfaces of the basement member and the fixing plate are brought together. Including,
In the fixed state, a through hole is provided as a light transmission window that vertically penetrates the basement member and the fixing plate, and the basement member extends from the first main surface along the axis of the through hole to the through hole. A counterbore part is formed by counterboring the peripheral part of the plate to a predetermined depth, and two plate-like optical crystal plates are sequentially stacked in the counterbore part so as to close the through-hole, and the fixing is performed. Along with fixing the plate to the basement member with the fixture, an elastic member for bringing the optical crystal plates into close contact with each other is provided along the peripheral edge of the through hole on the first main surface of the fixing plate. A sample holder for liquid oil set in an infrared spectroscopic measurement device, wherein a spacer member is inserted between the optical crystal plates so as not to interfere with at least the light transmission window, and the liquid oil is held in the gap. .   The sample holder for liquid oil according to claim 1, wherein the light transmission window is circular.   The sample holder for liquid oil according to claim 1, wherein the optical crystal plate has a quadrangular shape.   The sample holder for liquid oil according to claim 1, wherein the spacer member is an annular plate body surrounding the through hole.