Apparatus for adjusting optical path length of microvolume spectrophotometer

Abstract

The present invention relates to an apparatus for adjusting the optical path length of a microvolume spectrophotometer, which measures optical characteristics of light passing through a sample. An apparatus for adjusting the optical path length of a spectrophotometer according to the present invention comprises: a housing; a cover arm mounted to be hinge-rotated around a hinge shaft formed on one side of the upper portion of the housing; a cover arm stopper on which a free end of the cover arm in a closed state is placed; a lower pedestal to which light transferred from a lamp installed in the housing to an optical fiber is emitted; an upper pedestal supported by the cover arm and positioned on the upper portion of the lower pedestal; a lower pedestal moving means for enabling the lower pedestal to be vertically move relative to the upper pedestal; and a spectroscope configured such that light that is emitted from the lower pedestal and passes through the optical path is received through the optical fiber, and the physical property of the sample to be measured is analyzed and displayed. Surfaces of the lower pedestal and the upper pedestal, which face each other, are in a non-parallel state. The apparatus for adjusting the optical path length of a microvolume spectrophotometer according to the present invention can measure the absorbance in an ultra-high concentration section with high precision, without requiring precise control, with a simple structure.

Description

Optical path length adjustment device of a micro-spectrophotometer

[0001] The present invention relates to a spectrophotometer used to measure the optical properties of light passing through a sample, and more specifically, to an optical path length control device of a micro-spectrophotometer that enables precise measurements while ensuring improved reproducibility in measuring the optical properties of ultra-high concentration samples including trace amounts of nucleic acids or proteins.

[0002] Typically, liquids, mixtures, solutions, and reaction mixtures are measured for specific physical properties, often using spectrophotometers that utilize optical technology. These spectrophotometers measure the absorbance of a substance to analyze its concentration, purity, structure, and other properties.

[0003] However, since existing spectrophotometers have a fixed optical path length, it is difficult to accurately measure absorbance when the concentration of the sample is very high or very low. In particular, when measuring a high-concentration sample, the absorbance of the sample exceeds the measurement range, making accurate analysis impossible.

[0004] To address the aforementioned issues with conventional spectrophotometers, microvolume spectrophotometers have been developed and deployed. These microvolume spectrophotometers are capable of analyzing extremely small sample volumes and, through their variable optical path lengths, are known to be capable of precisely measuring a wide range of sample concentrations, from low to high.

[0005] In general, in micro spectrophotometers, even if the optical path length is different, the absorbance is displayed as converted to the optical path length of 10 mm, and by adjusting the optical path length, a wider range of absorbance can be measured with the same detector.

[0006] U.S. Patent No. 9,442,009 discloses the above-described ultra-micro spectrophotometer. The configuration and measurement process are as follows, as shown in Figure 1, which schematically illustrates the structure of the invention.

[0007] As illustrated, a conventional micro-spectrophotometer has an upper arm (102) formed on an outer side of a lower arm (104) that forms the upper portion of a housing (110) adjacent to a main body (100) equipped with a display, and is hinge-rotatably formed between an open position and a closed position, for example, in a range of 90°. An upper sample surface portion (106) is formed on the upper arm (102), and a lower sample surface portion (108) is formed on the lower arm (104) so ​​as to face each other. At this time, an end of an optical fiber (114) extended from the main body (100) is connected to the upper sample surface portion (106), and light from a lamp (112) built into the housing (110) is irradiated to the lower sample surface portion (108).

[0008] Meanwhile, inside the housing (110), a screw (118) driven by a motor (116) and a protruding extension (120) having one end joined thereto and the other end contacting the longitudinal central bottom surface of the upper arm (102) are formed.

[0009] Accordingly, when the motor (116) is operated, the screw (118) mounted on the motor drive unit rotates, and as the protruding extension (120) linked to the screw (118) moves up and down, the upper arm (102) in contact with it rotates slightly, resulting in a change in the distance between the upper sample surface (106) and the lower sample surface (108).

[0010] Figures 2 (a) to (c) show step-by-step the process of measuring a very small sample droplet using the spectrophotometer device of Figure 1. (a) shows a state where a sample is dropped onto the upper sample surface using a pipette, (b) shows a state where the upper arm of (a) is rotated in a closed state so that the sample and the upper sample surface are in contact due to surface tension, and (c) shows a state where the distance between the upper and lower sample surfaces is adjusted for measurement of the sample in the state of (b).

[0011] As in (a) of Fig. 2, when the sample (S) is dropped on the lower sample surface (108) of the lower arm (104) with the upper arm (102) open and the upper arm (102) is then switched to the closed state, the upper part of the sample (S) comes into contact with the upper sample surface (106) as in (b), and the central part of the sample column becomes narrower than the upper and lower parts due to the surface tension of the liquid sample (S).

[0012] In the above state (b), the distance between the upper sample surface portion (106) and the lower sample surface portion (108) is controlled by the operation of the motor (116). This is achieved by operating the motor (116) to lower the protruding extension portion (120) according to the rotation of the screw (118). That is, from the state (b), as in (c), the distance between the upper and lower sample surfaces is reduced from L1 to L2, and accordingly, the width of the sample (S) is increased.

[0013] In the state (D) of FIG. 3, light transmitted from the lamp (112) to the lower sample surface (108) passes through the sample (S). The amount of light transmitted through the sample (S) to reach the upper sample surface (106) is measured, and the result measured in this way is displayed as absorbance on the display of the main body (100).

[0014] Meanwhile, absorbance (A) follows the Beer-Lambert law.

[0015]

[0016]

[0017] Here;

[0018] : Intensity of incident light

[0019] : Intensity of incident light

[0020] ε: Absorption coefficient of the medium

[0021] c: concentration of the medium

[0022] L: distance traveled by light in a medium

[0023]

[0024] As in the above equation, the absorbance (A) is directly related to the travel distance (L) of light in the medium, i.e. the optical path. In particular, in the case of a micro-spectrophotometer, when calculating the absorbance of the sample (S) shown in Figure 2, Ina The difference between them rather than themselves The above distance difference is used because will affect the accuracy of absorbance, Ina is directly used to calculate absorbance.

[0025] In this way, the distance control between the upper and lower sample surface portions (106, 108) greatly affects the accuracy of the absorbance. As discussed above, the distance control between the upper and lower sample surface portions in the device of the prior art is achieved by the hinge rotation of the upper arm (102) in contact with the protruding extension portion (120) that is moved up and down by the motor (116). However, the distance control method of this type has the following problems.

[0026] First, in conventional devices, the height of the upper arm is adjusted through a linear actuator consisting of a motor, a screw, and a protruding extension that contacts the upper arm, which causes the optical fiber to move together with the upper arm, which may reduce the measurement accuracy.

[0027] In addition, due to the backlash of the motor and screw, it is difficult to precisely control the position of the protruding extension, which may result in a decrease in position reproducibility, and accordingly, a decrease in measurement precision due to a decrease in optical path accuracy is inevitable.

[0028] Recent technological developments in ultra-trace spectrophotometry are moving toward expanding the concentration measurement range, and accordingly, the measurement section is also encompassing a concentration range from low to high concentration, and the optical path setting section is also being subdivided into several stages.

[0029] Recently, ultra-high concentration measurements with absorbances exceeding 500 Abs / cm are becoming increasingly required. To implement these multiple optical path steps, stepper motors capable of precise control of the optical path length are primarily used.

[0030] Meanwhile, in order to increase the measurable concentration range to ultra-high concentrations, an extremely short optical path on the order of tens of micrometers is required. In this case, even if a certain degree of precision control is performed using a step motor during sample measurement, it is difficult to achieve satisfactory precision in optical path adjustment, which reduces reproducibility and limits the ability to obtain measurement results with satisfactory reliability. For example, in a measurement section with an optical path of tens of micrometers, positional reproducibility on the order of sub-micrometers is required, but the development of an ultra-trace spectrophotometer that meets this requirement is not yet known.

[0031] The present invention was created in consideration of the above-mentioned shortcomings and problems pointed out in conventional micro-spectrophotometers, and the purpose of the present invention is to provide an optical path length control device of a micro-spectrophotometer capable of measuring absorbance in an ultra-high concentration range with high precision without requiring precise control with a simple structure.

[0032] Another object of the present invention is to provide an optical path length adjustment device for a micro-spectrophotometer capable of obtaining accurate and reliable analysis results along with achieving high reproducibility by configuring the opposing surfaces of the upper and lower pedestals to contact each other in a non-parallel state in an ultra-high concentration range, thereby eliminating the influence of the positional accuracy of the lower pedestal on the optical path length.

[0033] The above object of the present invention is achieved by including a housing, a cover arm mounted so as to be hinge-rotatably mounted about a hinge axis formed on one upper side of the housing, a cover arm stopper on which a free end of the cover arm in a closed state is placed, a lower pedestal on which light transmitted from a lamp installed inside the housing via an optical fiber is irradiated, an upper pedestal supported by the cover arm and positioned above the lower pedestal, a lower pedestal moving means for allowing the lower pedestal to vertically move relative to the upper pedestal, and a spectrometer that receives light irradiated from the lower pedestal and passing through an optical path through an optical fiber, analyzes the measured properties of a sample, and displays the same, wherein the opposing surfaces of the lower pedestal and the upper pedestal are in a non-parallel state, and an optical path length adjusting device of a micro-spectrophotometer is used.

[0034] The primary technical feature of the present invention is that, unlike conventional spectrophotometers, the opposing surfaces of the upper pedestal supported on the cover arm and the opposing surfaces of the lower pedestal, whose optical path length is adjusted by moving up and down by the lower pedestal moving means at its vertical lower portion, are in a non-parallel state, that is, a constant angle is maintained between the opposing surfaces of the two pedestals.

[0035] Another technical feature of the present invention is that the opposite surface of the lower pedestal moving toward the upper pedestal contacts the opposite surface of the upper pedestal at a predetermined angle to reproduce the optical path length of a preset ultra-high concentration section.

[0036] When the upper and lower pedestals come into contact, it is desirable to maintain the angle between the opposing surfaces of the two pedestals at 3° or less. At this time, the distance between the two pedestals, i.e. the optical path length, is approximately 1 mm or less, which is very short compared to the width of the light beam, so the change in light quantity according to the distance becomes negligibly small.

[0037] In the spectrophotometer according to the present invention, the upper pedestal maintains a fixed position with its end placed on the cover arm stopper because the optical path length is maintained in a state where the lower pedestal and the upper pedestal do not contact each other except in the ultra-high concentration section.

[0038] Meanwhile, in the ultra-high concentration section of the spectrophotometer according to the present invention, one side of the opposing surface of the lower pedestal moving toward the opposing surface of the upper pedestal comes into contact with the opposing surface of the upper pedestal, and upon such contact, the cover arm supported on the cover arm stopper is momentarily displaced to be slightly pushed upward.

[0039] Even if the upper pedestal is displaced from its original position by contact with the lower pedestal, the angle between the opposing surfaces formed when the two pedestals come into contact remains almost the same, so that no substantial change occurs in the optical path length.

[0040] In other words, in the ultra-trace spectrophotometer of the present invention, the influence of the limitations in positional accuracy due to backlash, etc., which inevitably occurs during the operation of the motor or screw constituting the lower pedestal moving means for moving the lower pedestal, on the moving distance can be significantly reduced.

[0041] In addition, the ultra-trace spectrophotometer according to the present invention is configured so that the angle of the opposing surfaces can be adjusted when the upper pedestal is assembled to the cover arm, thereby enabling the adjustment of the optical path length according to the change in angle when the opposing surfaces of the two pedestals touch each other. At this time, the optical path length increases in proportion to the angle formed by the opposing surfaces of the two pedestals.

[0042] Meanwhile, in the ultra-trace spectrophotometer according to the present invention, a desired optical path length can be set using a specific standard sample. For example, when a standard sample having an absorbance of 10 Abs per 1 cm is used, if the absorbance is adjusted to 0.03 Abs when one side of the opposing surfaces of two pedestals is in contact, the optical path length when the two pedestals are in contact becomes 0.03 mm.

[0043] The present invention can be commonly applied to a reflection-type micro-spectrophotometer and a transmission-type micro-spectrophotometer. The angle between the two pedestals of the reflection-type micro-spectrophotometer is preferably in the range of 0.5° to 1.5°, and in the transmission-type micro-spectrophotometer, it is preferably in the range of 1° to 3°, which is twice that angle.

[0044] In the optical path length control device of the ultra-trace spectrophotometer according to the present invention, absorbance in an ultra-high concentration range can be measured with high precision without requiring precise control due to its simple structure.

[0045] The present invention enables the precise implementation of a preset optical path length without being affected by the positional accuracy resulting from the movement of the lower pedestal when the opposing surfaces of the upper and lower pedestals are in contact in a non-parallel state in an ultra-high concentration region, thereby achieving high reproducibility and obtaining accurate and reliable analysis results, and further increasing the measurement limit of a micro-spectrophotometer.

[0046]

[0047] Figure 1 is a front view showing the overall structure of a conventional ultra-micro spectrophotometer.

[0048] Figures 2 (a) to 2 (c) are front views showing changes in optical path length during the sample measurement process using the spectrophotometer of Figure 1.

[0049] Figure 3 (a) is a diagram of the overall structure of a reflection-type ultra-micro spectrophotometer according to an embodiment of the present invention.

[0050] Figure 3 (b) is a diagram of the overall structure of a transmission-type ultra-micro spectrophotometer according to an embodiment of the present invention.

[0051] Enlarged view of the upper and lower pedestals shown in (a) and (b) of Fig. 3 of Fig. 4.

[0052] FIG. 5 is a side view showing the change in position of the lower pedestal and the cover arm when the upper and lower pedestals are in contact with each other according to one embodiment of the present invention.

[0053] Figure 6 is a cross-sectional view of an upper pedestal having an angle adjustment function according to one embodiment of the present invention.

[0054] Figures 7 (a) and (b) show that the angle of the opposing surfaces is adjusted by rotating the upper pedestal in the upper and lower pedestals having non-parallel opposing surfaces according to another embodiment of the present invention.

[0055] (a) is a plan view of the upper pedestal including the cover arm,

[0056] (I) is a cross-section of line AA of (A).

[0057] Figures 8 (a) and (b) show the process in which the absorbance of the sample changes as the distance between the upper and lower pedestals loaded with the liquid sample gets closer.

[0058] (A) is a graph of a comparative example in which the opposing surfaces of the upper and lower pedestals are parallel.

[0059] (I) is a graph of an example in which the opposing surfaces of the upper and lower pedestals are non-parallel.

[0060] Figures 9 (a) and (b) are graphs of repeated measurements of the spectrum of ultra-high concentration DNA.

[0061] (A) is a comparative example in which the opposing surfaces of the upper and lower pedestals are parallel,

[0062] (I) is an example in which the opposing surfaces of the upper and lower pedestals are non-parallel.

[0063] Figure 10 is a table comparing the measured concentration performance from the measurement results of Figure 9.

[0064] The above-described objects and the measurement process using the device, including the technical configuration, of the present invention will be understood in detail through the detailed description below with reference to the drawings of a preferred embodiment of the present invention.

[0065] FIG. 3 (a) is a diagram showing the overall structure of a reflection-type micro-spectrophotometer according to an embodiment of the present invention, FIG. 3 (b) is a diagram showing the overall structure of a transmission-type micro-spectrophotometer according to an embodiment of the present invention, and FIG. 4 is an enlarged view of the upper and lower pedestals shown in FIG. 3 (a) and (b).

[0066] First, as shown in (a) of FIG. 3, the optical path length adjustment device of the reflection-type micro-spectrophotometer is installed such that the cover arm (3) can rotate around the hinge axis (2) formed on one side of the upper portion of the square-shaped housing (1). On the free end side of the cover arm (3), a cover arm stopper (4) is formed on the opposite side of the hinge axis (2) on which the free end of the cover arm (3) in the closed state is placed.

[0067] Inside the housing (1), a lower pedestal moving means (8) is formed, which is composed of a step motor (5), a screw (6) that rotates by the step motor, and an elevation base (7) that is gear-coupled to the screw and moves vertically.

[0068] Meanwhile, a lower pedestal (9) is coupled to the upper end of the above-mentioned lifting base (7), and an upper pedestal (10) is coupled to the cover arm (3) directly above the lower pedestal (9).

[0069] Light from a lamp (11) installed inside the housing (1) is transmitted to the lower pedestal (9) by an optical fiber (12a) and irradiated toward the upper pedestal (10), and light reflected from the upper pedestal (10) is transmitted to a spectrometer (13) along an optical fiber (12b) to perform analysis of the physical properties of the sample to be measured and display of the analysis results.

[0070] Next, the optical path length adjustment device (1') of the transmission-type micro-spectrophotometer illustrated in (b) of FIG. 3 is identical to the device illustrated in (b) of FIG. 3, except that light irradiated from the lower pedestal (9) along the optical path length is transmitted to the upper pedestal (10) and the transmitted light is transmitted to the spectrometer (13) via an optical fiber (12c). Accordingly, identical components in (a) and (b) of FIG. 3 are given the same symbols.

[0071] As is known, the optical path length in a reflection spectrophotometer is twice that of a transmission spectrophotometer even though the distance between the upper and lower pedestals is the same.

[0072] In the optical path length adjustment device of the reflection and transmission type micro-spectrophotometer shown in (a) and (b) of Fig. 3, the upper surface of the lower pedestal (9) coupled to the lifting base (7) gear-coupled to the screw (6) rotated by the step motor (5) and the opposite surface to the upper pedestal (10) is maintained in a horizontal state and moves up and down in the vertical direction along with the lifting base (7).

[0073] Meanwhile, as illustrated in Fig. 4, the upper pedestal (10) fixed to the cover arm (3) is assembled so as to maintain a non-parallel state with the lower pedestal (9). To explain this in more detail, the opposing surface (LS) of the lower pedestal (9) remains horizontal, whereas the opposing surface (US) of the upper pedestal (10) assembled vertically above it deviates from the horizontal state and is assembled so that a specific angle (θ) is formed between these two opposing surfaces (LS)(US).

[0074] When the cover arm (3) is in a closed state as in (a) and (b) of Fig. 3, the upper pedestal (10) is supported on the cover arm stopper (4) and maintains a fixed position, but the lower pedestal (9) moves upward, and from the moment when the opposing surface (LS) of the lower pedestal (9) comes into contact with the inclined opposing surface (US) of the upper pedestal (10), the positions of the cover arm (3) and the upper pedestal (10) are determined according to the position of the lower pedestal (9).

[0075] Figure 4 is an enlarged drawing of the moment when the upper and lower pedestals come into contact. Since the two pedestals (9, 10) are tilted at a certain angle (θ), a certain gap exists between the two pedestals. This gap is a factor that determines the optical path of the sample, and when the two pedestals come into contact, the distance between the centers of the two pedestals (through which the light passes) ) is as follows.

[0076]

[0077] Here,

[0078] : Diameter of the upper pedestal

[0079] : Angle between two pedestals (rad)

[0080]

[0081] FIG. 5 is a side view showing the change in position of the lower pedestal and the cover arm when the upper and lower pedestals are in contact with each other according to one embodiment of the present invention. It shows the change in the displacement of the cover arm (3) according to the change in position of the lower pedestal (9) and the change in the distance between the centers of the two pedestals when the upper and lower pedestals (9, 10) are partially in contact with each other.

[0082] The distance between the two pedestals set as the control target When the position deviation of the lower pedestal (9) is If that much occurs, the distance deviation in the prior art directly affects the actual distance between the pedestals. Become That much error rate will occur.

[0083] However, in the ultra-high concentration range Since the error rate at this time can be very large because the distance is very short, at the level of tens of micrometers. Therefore, conventional technology requires high control precision with a deviation at the level of submicrometers.

[0084] On the other hand, as shown in Fig. 5, in the optical path length adjustment device of the ultra-micro spectrophotometer according to one embodiment of the present invention, the position deviation of the lower pedestal (9) When this occurs, the upper pedestal (10) and the lower pedestal (9) move together as one body while in contact with each other, and accordingly, the angle (9, 10) between the two pedestals and the angle of the cover arm (3) change together.

[0085] Therefore, the control objective The distance when the two pedestals touch When set to , the angle between the pedestals after the change due to deviation is , the distance between the two pedestals , change in the angle of the cover arm When the distance between two pedestals is is as follows: ( and (assuming that the rotation axes are on the same line)

[0086]

[0087]

[0088] Here,

[0089] : is the distance from the center axis of the upper pedestal of the cover arm to the center of the front axis

[0090]

[0091] Therefore, the distance between the two pedestals changes silver and in general According to Therefore, the optical path deviation can be reduced significantly compared to conventional technology.

[0092] As a result, the present invention can solve the problem of pedestal position reproducibility that occurs in the ultra-high concentration range, so that the angle between the two pedestals' opposing surfaces can be determined by considering only the luminous performance. For example, assuming that the maximum measurable absorbance of the spectrometer of a transmission-type micro-spectrophotometer is 2.5 Abs, the upper pedestal diameter is 2 mm, and the maximum absorbance to be measured is 750 Abs / cm, which is the world's highest level, the angle between the two pedestals is as follows.

[0093]

[0094]

[0095]

[0096] For reflective micro-spectrophotometers, the optical path length is doubled, so the angle is 0.5 times that of transmission spectrophotometers. While the angle between the two pedestals increases the maximum measurable absorbance, it also increases the minimum measurable absorbance in that area. Therefore, an appropriate angle design is necessary, taking into account the measurable range in that area.

[0097] Meanwhile, FIG. 6 is a cross-sectional view of an upper pedestal having an angle adjustment function according to one embodiment of the present invention, and with reference to this, the configuration and angle adjustment process for adjusting the angle of the upper pedestal will be described.

[0098] As shown, an upper pedestal insertion groove (3b) formed on a cover arm base (3a) rotatably connected to a hinge axis (2) is formed through a penetration, and a pair of nuts (3c) are vertically installed on both cover arm bases (3a) centered on the upper pedestal insertion groove (3b). At this time, the hinge axis (3), the pair of nuts (3c), and the upper pedestal insertion groove (3b) form a straight line.

[0099] Next, the upper pedestal (10) is assembled so as to be protruding and fixed to the lower center of the upper pedestal base (14) by passing through the upper pedestal insertion groove (3b). At this time, a pair of bolt insertion holes (14a) are formed in the area of ​​the upper pedestal base (14) corresponding to the pair of nut (3c) forming portions, and a bolt (15) inserted through each of these bolt insertion holes (14a) forms a screw connection with the nut (3c), so that the upper pedestal base (14) including the upper pedestal (10) is fixed on the cover arm base (3a).

[0100] At this time, a contact ball (16) supported by a spring (S) is formed on the inside of the bolt insertion hole (14a), that is, on the lower part of the upper pedestal base (14) between the bolt insertion hole and the upper pedestal (10), so that the upper pedestal (10) is elastically supported on the cover arm base (3a) and fixed through a screw connection between the pair of bolts (16) and the nut (3c).

[0101] In Fig. 6, the upper surface of the lower pedestal (9), i.e., the opposing surface (LS) of the lower pedestal, is horizontal, and the opposing surface (US) of the upper pedestal opposite thereto is assembled so as to form an angle that is offset by a predetermined angle (θ).

[0102] In the above state, the angle (θ) between the two opposing surfaces is adjusted by adjusting the insertion depth of the bolt (15) that penetrates the upper pedestal base (14) and is coupled with the nut (3c) on the cover arm base (3a). That is, based on the state shown in FIG. 6, if the bolt (16) is loosened from the existing state to shorten the insertion depth (or screw connection length) into the nut (3c), the left side of the upper pedestal base (14) is lifted relative to the cover arm base (3a), thereby increasing the angle compared to the angle (θ) before adjustment. Even if the right bolt (16) is further tightened, the same increase in angle occurs.

[0103] Conversely, if the left bolt (16) is tightened further or the right bolt is loosened, the angle will decrease from the original angle (θ).

[0104] The structure for adjusting the angle formed by the opposing surfaces of the upper and lower pedestals as described above has the advantage of being able to compensate for manufacturing or assembly tolerances, and adjustment to the desired angle is achieved by measuring the absorbance of a sample having a standard absorbance value and confirming the actual optical path length.

[0105] Meanwhile, (a) and (b) of FIG. 7 show that the angle of the opposing surfaces is adjusted by rotating the upper pedestal in the upper and lower pedestals having non-parallel opposing surfaces according to another embodiment of the present invention. (a) is a plan view of the upper pedestal including the upper arm, and (b) is a cross-sectional view taken along line AA of (a).

[0106] As shown, the angle adjustment device of the above embodiment has a similar overall configuration to the embodiment of FIG. 6, but the upper surface of the lower pedestal (9), which is the opposite surface (LS), deviates from the horizontal and is angled at a certain angle ( ) is inclined, and the opposite surface (UP) of the upper pedestal is also at a certain angle ( ) has a difference in that it is inclined as much as that.

[0107] In order to adjust the angle between the opposing surfaces in this embodiment, the upper pedestal base (14') connected to the nut (3c) on the cover arm base (3a) via the bolt (16) is configured to be rotatable. That is, as shown in (a) of Fig. 7, an arc-shaped guide groove (14'a) is formed to extend outward on both sides centered on the insertion groove of each bolt (16), and by holding the knob-shaped upper pedestal base (14') and rotating it to the left as indicated by the arrow, the optical path length is adjusted according to the change in the angle formed by the opposing surfaces (LS, US) of the upper and lower pedestals.

[0108] Next, (a) and (b) of Fig. 8 show the process in which the absorbance of the sample changes as the distance between the upper and lower pedestals loaded with the liquid sample becomes closer. (a) is a graph of a comparative example in which the opposing surfaces of the upper and lower pedestals are parallel, and (b) is a graph of an example in which the opposing surfaces of the upper and lower pedestals are non-parallel.

[0109] Figures 8 (a) and (b) show the process in which the absorbance of a liquid sample having an absorbance per unit length of about 10.53 Abs / cm at 303 nm is changed as the distance between two pedestals becomes shorter. In the example, the angle between the two pedestals was set to be about 1.5 degrees, and in the comparative example, the two pedestals were manufactured to be parallel to each other.

[0110] The X-axis represents the number of driving steps of the stepper motor that moves the lower pedestal. As the step distance increases, the lower pedestal rises and the distance between the two pedestals becomes closer.

[0111] In the case of the example shown in (b) of Fig. 8, it can be confirmed that the absorbance is also maintained constant as the optical path length becomes constant when the two pedestals are in contact from the section where the absorbance is about 0.03. This is because when the two pedestals are in contact, the optical path length is about 0.03 mm ( = 0.03 [Abs] / 10.53 [Abs / cm] * 10 [cm / mm] .

[0112] On the other hand, in the comparative example, it can be confirmed that the opposite surfaces of the two parallel pedestals are in perfect contact with each other, so that the absorbance approaches 0 Abs.

[0113] Next, (a) and (b) of Fig. 9 are graphs of repeated spectrum measurements of ultra-high concentration DNA. (a) is a comparative example in which the opposing surfaces of the upper and lower pedestals are parallel, and (b) is an example in which the opposing surfaces of the upper and lower pedestals are non-parallel. In addition, Fig. 10 is a table comparing the measurement concentration performance from the measurement results of Fig. 9.

[0114] These FIGS. 9 and 10 are results showing the performance improvement achieved by the present invention. In the case of the embodiment shown in (b) of FIG. 9, the angle between the two pedestals was set to 1.5 degrees, and the center-to-center distance between the two pedestals was configured to be 0.015 mm (0.03 mm, which is double the optical path length in the reflection type) when the two pedestals were in contact. In the case of the comparative example shown in the graph of (b), the two pedestals were manufactured to be parallel to each other, and then the step distance of the motor was controlled so that the distance between the two pedestals was 0.015 mm. For the performance evaluation, an ultra-high concentration dsDNA sample having a concentration of approximately 26,000 ng / μL (520 Abs / cm based on absorbance) was used, and the performance was analyzed through 10 repeated measurements.

[0115] In both experiments, the lower pedestal position was moved to the initial position before each measurement, and the lower pedestal was moved to the measurement position during the measurement to evaluate the position reproducibility of the lower pedestal and its effect on the concentration measurement performance.

[0116] Comparing the examples with the comparative examples through the results shown in Table 10, the examples show very low inter-spectral deviations. That is, as an example of quantitative analysis of measurement deviations, it is confirmed that performance is improved by approximately 10 times based on the CV value.

[0117]

[0118] [Explanation of symbols]

[0119] 1. Housing 2. Hinge shaft

[0120] 3. Cover arm 3a. Cover arm base

[0121] 3b. Upper pedestal insertion groove 3c. Nut

[0122] 4. Cover arm stopper 5. Stepper motor

[0123] 6. Screw 7. Lifting base

[0124] 8. Lower pedestal moving means 9. Lower pedestal

[0125] 10. Upper pedestal 11. Lamp

[0126] 12a, 12b, 12c. Fiber optics 13. Spectroscope

[0127] 14, 14'. Upper pedestal base 14a. Bolt insertion hole

[0128] 14'a. Ho-Hyeong Guide Home 15. Contact Ball

[0129] 16. Bolt LS, US. Opposite side

[0130] S. Spring

Claims

1. An optical path length adjustment device for a micro-spectrophotometer, comprising: a housing; a cover arm mounted so as to be hinge-rotatable about a hinge axis formed on one upper side of the housing; a cover arm stopper on which a free end of the cover arm in a closed state is placed; a lower pedestal on which light transmitted from a lamp installed inside the housing via an optical fiber is irradiated; an upper pedestal supported by the cover arm and positioned above the lower pedestal; a lower pedestal moving means for allowing the lower pedestal to vertically move relative to the upper pedestal; and a spectrometer for receiving light irradiated from the lower pedestal and passing through an optical path through an optical fiber and analyzing and displaying a measurement target physical property of a sample, wherein the opposing surfaces of the lower pedestal and the upper pedestal are non-parallel.

2. An optical path length adjustment device of a micro-spectrophotometer, characterized in that in the first paragraph, the opposing surfaces of the upper pedestal and the lower pedestal form an angle of 1° to 3°.

3. In the second paragraph, the spectrophotometer is a reflection-type micro spectrophotometer, and the optical path length adjustment device of the micro spectrophotometer is characterized in that the angle between the two pedestal opposing surfaces is 0.5° to 1.5°.

4. A device for adjusting the optical path length of a microscopic spectrophotometer, characterized in that in the first paragraph, the lower pedestal moving means comprises a stepper motor, a screw that rotates by a hole of the stepper motor, and an elevation base that is gear-coupled to the screw and vertically moves the lower pedestal.

5. A device for adjusting the optical path length of a micro-spectrophotometer, characterized in that in the first paragraph, the opposing surface of the lower pedestal is horizontal and the opposing surface of the upper pedestal is out of the horizontal state.

6. In the fifth paragraph, the optical path length adjustment device of the ultra-micro spectrophotometer is characterized in that the opposing surfaces of the upper and lower pedestals can be adjusted at an angle with respect to the opposing surface of the lower pedestal.

7. In the 6th paragraph, the angle adjustment of the upper pedestal opposing surface is achieved by forming a pair of bolt insertion holes in the upper pedestal base on which the upper pedestal is mounted, forming corresponding nuts on the cover arm base, and adjusting the relative insertion depth of bolts that are screwed into the nuts through each of the bolt insertion holes. A device for adjusting the optical path length of a micro-spectrophotometer.

8. In the 7th paragraph, the optical path length adjustment device of the ultra-micro spectrophotometer is characterized in that the upper pedestal base is formed so that the contact ball supported by the spring embedded inside the pair of bolt insertion holes is elastically contacted with the upper surface of the cover arm base.

9. A device for adjusting the optical path length of a micro-spectrophotometer, characterized in that the opposing surfaces of the upper and lower pedestals in the first paragraph are out of the horizontal state.

10. A device for adjusting the optical path length of a micro-spectrophotometer, characterized in that, in the 9th paragraph, the opposing surfaces of the upper and lower pedestals can be adjusted at an angle with respect to the opposing surface of the lower pedestal.

11. A device for adjusting the optical path length of a micro-spectrophotometer, characterized in that in the 10th paragraph, the angle adjustment of the upper pedestal opposing surface is achieved through rotation of the upper pedestal base on which the upper pedestal is mounted.

12. A device for adjusting the optical path length of a micro-spectrophotometer, characterized in that in the 11th paragraph, the rotation of the upper pedestal base is achieved through an arc-shaped guide groove formed to extend outward on both sides with a bolt insertion groove as the center, into which a pair of bolts for supporting the upper pedestal to the cover arm base are inserted.

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