JP7371531B2 - Fourier transform infrared spectrophotometer - Google Patents

Description

The present invention relates to a Fourier Transform InfraRed Spectrophotometer (hereinafter referred to as "FTIR").

In FTIR, an interferometer, typically a Michelson interferometer, generates infrared interference light with varying amplitude and irradiates it onto a sample, and the transmitted light that passes through the sample or the reflected light that is reflected by the sample is used as an interferogram. By performing Fourier transform processing on this interferogram, a spectrum (power spectrum) in which the horizontal axis represents the wave number (or wavelength) and the vertical axis represents the intensity is obtained. Here, a Michelson interferometer is a device that includes a beam splitter, a fixed mirror, a moving mirror, etc. The beam splitter splits the light into two, one is reflected by the fixed mirror, the other is reflected by the moving mirror, and then , which causes these two reflected lights to interfere.

Beam splitters are generally made of potassium bromide (KBr). Since KBr is a deliquescent material, in FTIR, the Michelson interferometer is housed in a sealed chamber, and a means for dehumidifying the sealed chamber is provided. The sample holder is provided in a sample chamber provided separately from the sealed chamber, and a sample can be mounted through an opening provided in the sample chamber without introducing the atmosphere into the sealed chamber. The interference light generated in the sealed chamber is irradiated onto the sample through a window provided in the sealed chamber and the sample chamber. These sealed chambers and sample chambers are generally housed within a common housing.

Patent Document 1 discloses that a first opening and a lid for closing the first opening are provided on the upper surface of a sealed chamber that houses a Michelson interferometer, and the inside of the sealed chamber communicates with the outside through the first opening. An FTIR has been described that has a structure that includes a box body. The box body is provided with a second opening different from the first opening, and the inside of the box body communicates with the space outside the box body within the sealed chamber through this second opening. A beam splitter is placed in the space, and a desiccant is housed inside the box. A commercially available desiccant can be used. In this FTIR, the lid of the sealed chamber is opened, the desiccant is contained in the box through the first opening, and then the first opening is sealed with the lid. As a result, the space in which the beam splitter is arranged is dehumidified by the desiccant.

On the other hand, Non-Patent Document 1 describes an FTIR that includes a sealed chamber that accommodates an interferometer. The inside of the sealed chamber is dehumidified by a dedicated desiccant cartridge, and the desiccant cartridge is inserted into the sealed chamber through an opening provided in the sealed chamber. A lid body that closes the opening is fixed to the desiccant cartridge, and by inserting the desiccant cartridge into the sealed chamber and closing the opening with the lid body, the inside of the sealed chamber is kept airtight. , dehumidified by the desiccant in the desiccant cartridge.

Japanese Patent Application Publication No. 10-253454

"Agilent Cary 630 FTIR Spectrometer User's Guide", published by Agilent Technologies, Inc.

In the apparatus described in Patent Document 1, when replacing the desiccant, the user takes out the used desiccant from the box and places a new desiccant into the box. To do this, the user must put his/her hand into the box through the first opening, which poses a problem in that it is difficult to perform the operation.

On the other hand, in the device described in Non-Patent Document 1, when replacing the desiccant, the user does not have to put his/her hand into the closed chamber, and can easily perform the task. However, in the device described in Non-Patent Document 1, it is necessary to replace the desiccant cartridge dedicated to the device, so a commercially available desiccant cannot be used, and the lid fixed to the desiccant cartridge cannot be used. Since the body is also disposable, there is a problem in that running costs for dehumidification become high.

The problem to be solved by the present invention is to provide an FTIR in which the desiccant can be easily replaced and the running cost for dehumidification can be suppressed.

The FTIR according to the present invention, which was made to solve the above problems,
an interferometer including a deliquescent optical element;
a sealed chamber containing the interferometer and having an opening;
A desiccant unit includes a lid that can seal the opening, and a case that accommodates a desiccant and is removably attached to the lid and has a shape that can be inserted into the sealed chamber from the opening. .

In the FTIR according to the present invention, the desiccant is housed in the case with the case of the desiccant unit removed from the lid. A commercially available desiccant can be used as this desiccant. Then, the case part is attached to the lid part, the case part is inserted into the sealed chamber through the opening of the sealed chamber, and the opening is sealed with the lid part. This places the desiccant inside the closed chamber. When replacing the desiccant, remove the lid from the sealed chamber and take out the desiccant unit from the sealed chamber. Then, the case part is removed from the lid part, the used desiccant is taken out from the case part, and a new desiccant is stored in the case part. Thereafter, a new desiccant is placed in the sealed chamber by performing the same operation as above.

According to the FTIR according to the present invention, the desiccant can be easily replaced without the user putting his/her hands into the sealed chamber, and a commercially available desiccant can be used, and the lid can be used repeatedly. , running costs for dehumidification can be reduced.

1 is a schematic configuration diagram showing an embodiment of FTIR according to the present invention. FIG. 2 is a perspective view of a desiccant unit that is a component of the FTIR of this embodiment. FIG. 2 is a schematic side view of a desiccant unit in FTIR of this embodiment. However, some members that cannot be seen from the side are shown in cross section. FIG. 3 is an exploded view of a desiccant unit in FTIR of this embodiment. FIG. 3 is a developed view of a case part that is a component of the desiccant unit. FIG. 2 is a partially enlarged view of a sealed chamber and a casing in the FTIR according to the present embodiment, showing how a desiccant unit is attached to the opening of the sealed chamber. The back perspective view of the lid part of the desiccant unit of a modification to which the dehumidification device was attached. The front perspective view of the lid part and case part in the desiccant unit of a modification.

An embodiment of FTIR according to the present invention will be described using FIGS. 1 to 5.

(1) Configuration of FTIR according to the present embodiment In the FTIR 1 according to the present embodiment, as shown in FIG. 1, a sealed chamber (interferometer chamber) 10 and a sample chamber 20 are housed in a housing 30.

The sealed chamber 10 is airtight, and a main interferometer consisting of an infrared light source 100, a condensing mirror 101, a collimator mirror 102, a beam splitter 103, a fixed mirror 104, and a movable mirror 105 is provided inside. It is being The beam splitter 103 is made of KBr, which is a deliquescent material. Also, inside the sealed chamber 10, there are a laser light source 106, a first laser mirror 107, a second laser mirror 108, a laser detector 109, a beam splitter 103 common to the main interferometer, a fixed mirror 104, and a movable mirror. A control interferometer consisting of 105 is also provided. The main interferometer is used to generate main interference light that is irradiated onto the sample, and the control interferometer is used to control the position of the movable mirror 105. A driver 1051 that moves the movable mirror 105 is connected to the movable mirror 105 .

A rectangular opening 11 is provided on the wall of the sealed chamber 10 at a position close to the wall of the casing 30. A housing opening 31 is provided on the wall surface of the housing 30 facing this opening 11. The opening 11 can be hermetically closed by a lid 41 of a desiccant unit 40, which will be described later. Furthermore, a sealed chamber window 12 is provided on the wall of the sealed chamber 10, which is a window through which the main interference light generated by the main interferometer passes.

Inside the housing 30, outside the sealed chamber 10, the main interference light emitted from the main interferometer and passed through the sealed room window 12 is transmitted via a parabolic mirror 301, a sample chamber 20, and an ellipsoidal mirror 302. Each of these parts is arranged so as to be introduced into the infrared light detector 303.

The sample chamber 20 is equipped with accessories (not shown) depending on the measurement method. For example, when performing total reflection measurement (ATR), a sample holder and a prism pressed against the sample 91 held in the sample holder are used to make infrared light incident on the sample at a predetermined angle and to measure total reflection by the sample. An accessory having an optical system for introducing infrared light into the infrared light detector 303 is housed in the sample chamber 20 . When performing transmission measurement, an optical system is used to make infrared light incident on the sample holder and the sample 91 held in the sample holder at a predetermined angle, and to introduce the infrared light that has passed through the sample into the infrared light detector 303. An accessory having a system is housed within the sample chamber 20.

On the wall surface of the sample chamber 20, there is a sample chamber entrance window 201, which is a window through which the main interference light reflected by the parabolic mirror 301 enters into the sample chamber 20, and the main interference light reflected by the sample 91 in the sample chamber 20. Alternatively, a sample chamber exit window 202 is provided, which is a window through which the main interference light transmitted through the sample 91 is output from inside the sample chamber 20 .

A desiccant unit 40 shown in FIGS. 2A to 2C is installed in the sealed chamber 10. The configuration of the desiccant unit 40 will be explained below.

The desiccant unit 40 includes a lid part 41 that can seal the opening 11, and a case part 42 that is detachably attached to the lid part 41.

The lid portion 41 includes a flat lid body 411, a case receiving member 412 and a sealing material 413 provided on one surface of the lid body 411.

The case receiving member 412 has two case receiving parts 4121 formed by vertically bending the vicinity of two opposing sides of a rectangular plate-like member along folding lines parallel to those two sides, spaced apart from each other and extending parallel to each other. , are arranged perpendicularly to the lid body 411. A flat plate portion 4123 between the two case receiving portions 4121 of the case receiving member 412 is fixed to the one surface of the lid body 411. The interval between the two case receiving parts 4121 is shorter than the long side of the opening 11 of the sealed chamber 10. Each of these two case receiving parts 4121 is provided with two (four in total in two case receiving parts 4121) protrusions 4122 on the surface facing the other case receiving part 4121.

The sealing material 413 is a linear material that surrounds an area slightly larger than the outer edge of the opening 11 of the sealed chamber 10. The case receiving member 412 is arranged inside the area surrounded by the sealing material 413.

One screw passage hole 414 (four in total) is provided in each of the four corners of the lid body 411 outside the area surrounded by the sealing material 413. A hand-tight screw 43, which is a male thread, is inserted into each screw passage hole 414 one by one.

A hole 415 is provided in the center of the lid body 411, and a transparent glass plate 417 is provided in airtight contact with the lid body 411 so as to close the hole 415. Further, a sheet-shaped humidity indicator 416 is fixed by being sandwiched between a flat plate portion 4123 of the case receiving member 412 and a glass plate 417. A humidity indicator hole 4124 is provided in the flat plate portion 4123 of the case receiving member 412 at a position facing the hole 415 of the lid body 411 via the humidity indicator 416 (see FIG. 2B for the above. In FIG. 2C, the humidity indicator 416 is not shown, and the position where the humidity indicator 416 is fixed is indicated by a broken line). The humidity indicator 416 changes color depending on the surrounding humidity. With this configuration, the color of the humidity indicator 416 changes depending on the humidity inside the sealed room 10, and it is possible to check the color of the humidity indicator 416, that is, the humidity inside the sealed room 10, from outside the FTIR 1 through the glass plate 417. can.

The case portion 42 is formed by bending a flexible plate material. In this embodiment, a plate made of metal (stainless steel in this example, but other metal materials are also possible) is used that is thin enough to be bent by hand. FIG. 3 shows the shape of the plate material before it is bent. In FIG. 3, a first side wall 4211, a first top wall 4217, a second top wall 4218, and a second side wall 4212 are continuous in order from the left. In addition, in this developed view, a plate constituting the third side wall 4213 is placed below the first side wall 4211 and the second side wall 4212, and a fourth plate is placed above the first side wall 4211 and the second side wall 4212. A plate forming the side wall 4214 is placed below the first top wall 4217 and the second top wall 4218, and a plate forming the fifth side wall 4215 is placed above the first top wall 4217 and the second top wall 4218. A plate forming each of the six side walls 4216 is provided. This metal plate is folded at an acute angle between the first top wall 4217 and the second top wall 4218 (acute angle fold line 422), and between the first side wall 4211 and the first top wall 4217 and the second top wall 4218 The first side wall 4211 and the second side wall 4212 are each folded at an obtuse angle between the first side wall 4211 and the second side wall 4212, and the other walls are folded at a right angle. As a result, as shown in FIGS. 2A to 2C, a case portion 42 having a space for accommodating the desiccant 92 surrounded by these side walls and the top wall is constructed.

The third side wall 4213 and the fourth side wall 4214 constitute the side wall of the case portion 42 in a state where they are each divided into a portion connected to the first side wall 4211 and a portion connected to the second side wall 4212. The gap 423 between these two parts is large enough to prevent the desiccant 92 from passing through, and the desiccant 92 will not unexpectedly exit the case portion 42 through the gap 423. Similarly, the fifth side wall 4215 and the sixth side wall 4216 are connected to the first top wall 4217 and the second top wall 4218, respectively, with a gap 423 large enough to prevent the desiccant 92 from passing through. divided into parts.

The first side wall 4211 and the second side wall 4212 are provided with protrusion engaging holes 424, one each at positions corresponding to the four protrusions 4122 provided on the case receiving part 4121 of the lid part 41. Further, the first side wall 4211 to the fourth side wall 4214, the first top wall 4217, and the second top wall 4218 are provided with a large number of gas passage holes 425 having a size that allows gas to pass through but not the desiccant 92. .

Around the opening 11 of the sealed chamber 10, female threads 32 that engage with manual tightening screws 43 are provided at positions corresponding to the four screw passing holes 414 provided in the lid body 411 (Fig. 4). reference).

In addition, the FTIR 1 includes a control section 33. The control section 33 controls each section constituting the main interferometer and the control interferometer, and also receives the detection signal obtained by the infrared light detector 303 and performs signal processing.

(2) Operation of FTIR of this embodiment Below, first, the operation of measurement by FTIR 1 of this embodiment will be briefly explained, and then the operation of replacing the desiccant will be explained in detail.

(2-1) Operation of measurement using FTIR 1 First, the user attaches an accessory according to the purpose of measurement to the sample chamber 20, and causes the sample holder included in the accessory to hold the sample 91. Next, infrared light is emitted from the infrared light source 100. Infrared light is introduced into a beam splitter 103 via a condenser mirror 101 and a collimator mirror 102, and is split into two. One infrared light is reflected by a fixed mirror 104 and returns to the beam splitter 103, and the other infrared light is reflected by a movable mirror 105 and returns to the beam splitter 103. This generates main interference light in which these two lights interfere. This main interference light is detected by an infrared light detector 303 via the closed chamber window 12, the parabolic mirror 301, the sample chamber 20, and the ellipsoidal mirror 302. By detecting this infrared light while moving the movable mirror 105, the control unit 33 obtains an interferogram, and performs a Fourier transform on the interferogram, so that the horizontal axis represents the wave number and the vertical axis represents the wave number. Obtain the power spectrum with intensity.

During this time, the control unit 33 acquires the detection signal generated by the laser detector 109. This detection signal corresponds to the intensity of the laser light that interfered with the control interferometer, and the moving distance of the movable mirror 105 can be determined from the change in this intensity. Based on the travel distance determined in this manner, the control unit 33 transmits a signal to the driver 1051 to control the position of the movable mirror 105.

As mentioned above, the beam splitter 103 is made of a deliquescent material, and the desiccant 92 is accommodated in the case portion 42 of the desiccant unit 40, and the case portion 42 is placed inside the sealed chamber 10, so that The interior of the sealed chamber 10 is maintained in a dry state.

(2-2) Desiccant replacement operation First, as a premise for explaining the desiccant 92 replacement operation, we will explain the operation of attaching the case part 42 to the lid part 41 and the operation of removing the case part 42 from the lid part 41. explain.

When attaching the case part 42 to the lid part 41, the first side wall 4211 and the second side wall 4212 are manually pushed from the outside of the case part 42 in a direction in which they approach each other. As a result, the case portion 42 bends to a more acute angle at the acute angle mountain fold line 422, and the first side wall 4211 and the second side wall 4212 approach each other. While pressing the first side wall 4211 and the second side wall 4212 in this way, insert the ends of the first side wall 4211 and the second side wall 4212 into the two case receiving parts 4121 provided on the lid part 41. Insert between. Then, the four protrusions 4122 provided on the case receiving part 4121 and the four protrusion engaging holes 424 provided in the case part 42 are aligned, and the hand that was pressing the case part 42 is released. Thereby, the protrusion 4122 and the protrusion engagement hole 424 are engaged, and the case portion 42 can be attached to the lid portion 41.

On the other hand, when the protrusion 4122 and the protrusion engagement hole 424 are disengaged by pushing the first side wall 4211 and the second side wall 4212 with human hands in the same manner as described above, and the case part 42 is separated from the lid part 41, the case The portion 42 can be removed from the lid portion 41.

When storing the desiccant 92 in the sealed chamber 10, first, the desiccant 92 is stored in the case part 42 with the case part 42 removed from the lid part 41, and then the desiccant 92 is stored in the case part 42 by the above method. is attached to the lid part 41. Next, as shown in FIG. 4, the case portion 42 is inserted into the sealed chamber 10 through the opening 11. Then, the lid part 41 is fixed to the wall of the sealed chamber 10 by screwing the four hand-tight screws 43 into the female threads 32 provided around the opening 11, respectively. As a result, the lid portion 41 is pressed against the wall of the sealed chamber 10 with the sealing material 413 interposed therebetween, so that the opening 11 is sealed by the lid portion 41. By the above operation, the desiccant 92 in the case portion 42 is accommodated in the sealed chamber 10.

When replacing the desiccant 92 after it has been used in the sealed chamber 10 for a predetermined period, first remove the hand-tightening screw 43 from the internal thread 32 and move the lid 41 to remove the case 42 from inside the sealed chamber 10. Take it out. Next, the case portion 42 is removed from the lid portion 41 using the method described above. Then, the used desiccant 92 inside the case section 42 is taken out, and a new desiccant 92 is stored inside the case section 42. Thereafter, the case part 42 is attached to the lid part 41 by the method described above, the case part 42 is inserted into the sealed chamber 10 through the opening 11, and the lid part 41 is fixed to the wall of the sealed chamber 10. The replacement work has been completed.

According to the embodiment described above, the desiccant 92 can be easily replaced without the user putting his/her hand into the sealed chamber 10 . Furthermore, since a commercially available desiccant can be used as the desiccant 92 and the lid part 41 can be used repeatedly, running costs for dehumidification can be suppressed.

Further, in the above embodiment, the case part 42 is attached to and detached from the lid part 41 by manually bending the case part 42 formed by bending a flexible plate material, and by manually tightening the screws 43. The desiccant unit 40 is attached to and detached from the closed chamber 10. Thereby, the desiccant 92 can be replaced without using any tools.

(3) Modification Next, a desiccant unit as a modification will be described. In this modification, as shown in FIGS. 5A and 5B, a dehumidifier 50 is further provided in the desiccant unit 40 in the above embodiment. The dehumidifier 50 is an electric dehumidifier operated by electric power, and is provided so as to close the hole 415 of the lid body 411. In this variation, humidity indicator 416 is not used. Dehumidifier 50 includes a connector 51 for supplying power thereto. A plate-shaped protection plate 52 is provided on the surface of the lid portion 41 on which the case receiving member 412 and the like are provided so as to cover the dehumidifier 50 via legs 521. The configuration of the case portion 42 is similar to that of the above embodiment. Note that the protection plate 52 is provided to prevent the desiccant 92 housed in the case portion 42 from moving and colliding with the dehumidifier 50 .

In this modification, the method of accommodating the desiccant 92 (the case portion 42 in which it is accommodated) in the sealed chamber 10 and the method of exchanging the desiccant 92 are the same as in the above embodiment. The dehumidifier 50 is operated by connecting the connector 51 to a power source (not shown) while the case portion 42 is housed in the sealed chamber 10. Note that the connector 51 is not housed within the sealed chamber 10.

In this modification, the inside of the sealed chamber 10 can be dehumidified more reliably by using the dehumidifier 50 and the desiccant 92 housed in the case part 42 together. Note that the case portion 42 may be housed in the sealed chamber 10 without housing the desiccant 92 in the case portion 42, and the inside of the sealed chamber 10 may be dehumidified using only the dehumidifier 50.

Electric dehumidifiers generally allow external gas to pass through when not energized. Therefore, in the configuration of the modified example, the dehumidifier 50 basically operates at all times, including when not measuring. When the dehumidifier 50 is stopped, such as when measurements are not performed for a long period of time, the desiccant unit 40 with the dehumidifier 50 is removed from the sealed chamber 10, and instead, the desiccant unit 40 without the dehumidifier 50 in the above embodiment A desiccant 92 is stored in the unit 40 and then installed in the sealed chamber 10.

The present invention is not limited to the above embodiments and modifications, and further modifications are possible.

For example, in the above embodiment, in order to fix the case part 42 to the lid part 41, the projection 4122 was provided on the lid part 41 and the projection engagement hole 424 was provided in the case part 42. A protrusion engaging hole may be provided in the portion.

In the embodiment described above, in order to be able to replace the desiccant 92 without using tools, the case part 42 formed by bending a flexible plate is bent manually. 42 to the lid 41 and the desiccant unit 40 to the sealed chamber 10 using hand-tightened screws 43. The agent unit 40 may be screwed to the sealed chamber 10.

The shape of the case portion 42 is not limited to the above example, and may be, for example, a simple rectangular parallelepiped shape.

In the above modification, the dehumidifier 50 is attached to the lid portion 41, but the dehumidifier may be attached to the case portion.

[Mode]
It will be appreciated by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.

(Section 1)
FTIR related to paragraph 1 is:
an interferometer including a deliquescent optical element;
a sealed chamber containing the interferometer and having an opening;
A desiccant unit includes a lid that can seal the opening, and a case that accommodates a desiccant and is removably attached to the lid and has a shape that can be inserted into the sealed chamber from the opening. .

In the FTIR according to item 1, the desiccant is housed in the case with the case of the desiccant unit removed from the lid. A commercially available desiccant can be used as this desiccant. Then, the case part is attached to the lid part, the case part is inserted into the sealed chamber through the opening of the sealed chamber, and the opening is sealed with the lid part. This places the desiccant inside the closed chamber. When replacing the desiccant, remove the lid from the sealed chamber and take out the desiccant unit from the sealed chamber. Then, the case part is removed from the lid part, the used desiccant is taken out from the case part, and a new desiccant is stored in the case part. Thereafter, a new desiccant is placed in the sealed chamber by performing the same operation as above.

According to the FTIR according to Paragraph 1, the user can easily replace the desiccant without putting their hands inside the closed room, can use a commercially available desiccant, and can use the lid repeatedly. This makes it possible to reduce running costs for dehumidification.

(Section 2)
The FTIR according to Paragraph 2 is the FTIR according to Paragraph 1.
The case portion is formed by bending a flexible plate material,
Either one of the case part and the lid part is provided with a plurality of protrusions, and the other is provided with a hole that can engage each of the protrusions at a position corresponding to each of the plurality of protrusions. is provided.

According to FTIR according to Item 2, a desiccant is stored in the case part, and each of the plurality of protrusions is engaged with a hole provided at a corresponding position while bending the plate material of the case part. By doing so, the case portion is attached to the lid portion. When taking out the desiccant from the case part, the case part is removed from the lid part by removing each of the plurality of protrusions from the holes while bending the plate material of the case part. Thereby, the case part can be easily attached to the lid part and removed from the lid part without using any tools.

(Section 3)
FTIR according to Paragraph 3 is FTIR according to Paragraph 1 or Paragraph 2.
a plurality of internal threads are formed on the wall of the sealed chamber around the opening;
Screw passage holes are formed in the lid at positions corresponding to each of the plurality of female screws,
moreover,
the same number of hand-tight male screws as the plurality of female screws, one of which can be screwed into each of the plurality of female screws;
A sealing material provided on the lid portion at a position facing the wall of the sealed chamber so as to surround the opening.

According to the FTIR according to Item 3, by tightening the male screw by hand, the sealing material is pressed against the wall around the opening of the sealed chamber and the lid is fixed to the wall, so the lid can be fixed without using any tools. The opening can be sealed by the part.

(Section 4)
The FTIR according to Item 4 is the FTIR according to any one of Items 1 to 3, further including a humidity measuring section that measures the humidity inside the sealed chamber.

According to the FTIR described in item 4, the user can determine the timing to replace the desiccant based on the humidity in the sealed room obtained by the humidity measuring section.

As such a humidity display section, for example, a sheet-shaped humidity indicator that is attached to cover a hole provided in the lid and whose color changes depending on the humidity can be used. In this example, the humidity inside the closed room can be determined by checking the color of the humidity indicator through the hole.

(Section 5)
The FTIR according to Item 5 is the FTIR according to any one of Items 1 to 4, in which a dehumidifier is further attached to a position facing the opening of the lid part or to the case part.

According to the FTIR according to item 5, the inside of the sealed room can be more reliably dehumidified by using a dehumidifying device in addition to the desiccant. Alternatively, dehumidification may be performed by omitting the desiccant and using only the dehumidifier.

1...FTIR
10... Sealed chamber 100... Infrared light source 101... Concentrating mirror 102... Collimator mirror 103... Beam splitter 104... Fixed mirror 105... Movable mirror 1051... Movable mirror driver 106... Laser light source 107... First laser mirror 108... First 2 Laser mirror 109... Laser detector 11... Sealed chamber opening 12... Sealed chamber window 20... Sample chamber 201... Sample chamber entrance window 202... Sample chamber exit window 30... Housing 301... Parabolic mirror 302... Elliptical surface Mirror 303...Infrared light detector 31...Casing opening 32...Female screw 33...Control unit 40...Desicant unit 41...Lid 411...Lid body 412...Case receiving member 4121...Case receiving part 4122...Protrusion 4123...Case holder Flat plate part 4124 of the member...humidity indicator hole 413...sealing material 414...screw passage hole 415...hole 416 provided in the lid body...humidity indicator 417...glass plate 42...case part 4211...first side wall 4212...second side wall 4213 ...Third side wall 4214...Fourth side wall 4215...Fifth side wall 4216...Sixth side wall 4217...First top wall 4218...Second top wall 422...Acute angle fold line 423...Gap 424...Protrusion engagement hole 425...Gas passage hole 50... Dehumidifier 51... Connector 52... Protective plate 521... Leg 91... Sample 92... Desiccant

Claims (4)

an interferometer including a deliquescent optical element;
a sealed chamber containing the interferometer and having an opening;
a dryer, which is removably attached to the lid, has a shape that can be inserted into the sealed chamber from the opening, and is formed by bending a flexible plate material; and a desiccant unit having a case portion for accommodating the desiccant ,
Either one of the case part and the lid part is provided with a plurality of protrusions, and the other is provided with a hole that can engage each of the protrusions at a position corresponding to each of the plurality of protrusions. is provided,
Fourier transform infrared spectrophotometer. an interferometer including a deliquescent optical element;
a sealed chamber containing the interferometer, the chamber having an opening and having a plurality of internal threads formed in a wall around the opening ;
the same number of hand-tight male screws as the plurality of female screws, one of which can be screwed into each of the plurality of female screws;
a lid that is capable of sealing the opening and has a screw passage hole formed at a position corresponding to each of the plurality of internal threads; and a lid that is removably attached to the lid and enters the sealed chamber from the opening. A desiccant unit having a case part that accommodates a desiccant and having an insertable shape , and a sealing material provided so as to surround the opening at a position of the lid part facing the wall of the sealed chamber. Fourier transform infrared spectrophotometer. The Fourier transform infrared spectrophotometer according to claim 1 or 2 , further comprising a humidity measuring section that measures the humidity in the sealed chamber. The Fourier transform infrared spectrophotometer according to any one of claims 1 to 3 , further comprising a dehumidifier installed at a position facing the opening of the lid or at the case.

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