CN115096841B - Terahertz spectrum-based liquid sample spectrum test system, method and sample cell - Google Patents

Abstract

The embodiment of the invention discloses a liquid sample spectrum test system and method based on terahertz spectrum and a sample cell. The liquid sample cell includes: the sample cell body is of a containing bin structure with an opening at the top and formed by a bottom plate and side plates; and the separation sheet is positioned inside the sample cell body and connected with the bottom plate and the two opposite side plates, and separates the sample cell body to form two accommodating bins. The embodiment of the invention solves the problems of inaccurate reference signal and long time consumption in the test process caused by the environment change in the prior liquid sample spectrum test by sequentially measuring the reference signal and the sample signal, and realizes the technical effects of measuring the reference signal and the sample signal in the same environment and shortening the test time.

Description

Liquid sample spectrum testing system, method and sample cell based on terahertz spectroscopy

Technical Field

The embodiments of the present invention relate to liquid sample analysis and detection technology, and in particular to a liquid sample spectrum testing system, method and sample pool based on terahertz spectroscopy.

Background Art

The testing of liquid sample spectral signals is an extremely important technical means in the field of liquid sample analysis and detection today. For example, the concentration and solute type of liquid samples are analyzed. However, in the prior art, for the means of liquid sample spectral testing, researchers generally use the method of measuring an empty sample pool and a sample pool filled with liquid to obtain a reference signal and a sample signal respectively. However, this makes the measurement environment of the reference signal and the sample signal different, and it takes a long time, which affects the credibility of the liquid sample spectral signal.

Summary of the invention

The present invention provides a liquid sample spectrum testing system, method and sample pool based on terahertz spectroscopy, which can ensure that the reference signal and the sample signal are measured in the same environment and reduce the time consumption of the testing process.

In a first aspect, an embodiment of the present invention provides a liquid sample pool, comprising:

The sample pool body is a storage chamber structure with an opening on the top, which is composed of a bottom plate and side plates;

The partition piece is located inside the sample pool body, the partition piece is connected to the bottom plate and the two opposite side plates, and the partition piece partitions the sample pool body to form two accommodating compartments.

Furthermore, in the liquid sample pool, the partition piece is made of the same material as the sample pool body.

Furthermore, in the liquid sample pool, the thickness dimension _d1 of the partition piece and the width dimension _d2 of the side plate connected to the partition piece satisfy: _d1 / _d2≤5 %.

In a second aspect, an embodiment of the present invention further provides a liquid sample spectrum testing system based on terahertz spectroscopy, wherein the system comprises a liquid sample pool as described in the first aspect, and further comprises a light emitting unit and a light receiving unit, wherein the liquid sample pool is used to be placed between the light emitting unit and the light receiving unit;

The light emitting unit is used to project a test light beam based on terahertz spectrum parallel to the partition piece of the liquid sample pool to the liquid sample pool, and make part of the test light beam be transmitted through one containing chamber of the liquid sample pool, and another part of the test light beam be transmitted through another containing chamber;

The light receiving unit is used to receive the light beams transmitted through the two accommodating chambers.

Furthermore, in the test system, the number of the light receiving unit is one, and the light receiving unit simultaneously receives the light beams projected through the two containing chambers of the liquid sample pool.

Furthermore, the test system further includes a beam amplification unit, which is located between the light emitting unit and the liquid sample pool, and is used to amplify the test beam projected by the light emitting unit.

Furthermore, in the test system, the size of the test beam amplified by the beam amplification unit is greater than or equal to 10 mm.

Furthermore, in the test system, the size D ₁ of the incident surface of the liquid sample pool and the size D ₂ of the light spot formed by the test light beam on the incident surface satisfy the following relationship: D ₂ <D ₁ <2D ₂ .

In a third aspect, an embodiment of the present invention further provides a liquid sample spectrum testing method based on terahertz spectroscopy, wherein the liquid sample spectrum testing system based on terahertz spectroscopy described in the second aspect is applied, and the testing method includes:

Adding a liquid sample to be tested into one of the containing chambers of the liquid sample pool;

Turning on the light emitting unit to project a test light beam based on terahertz spectrum parallel to the partition piece of the liquid sample pool to the liquid sample pool, and allowing part of the test light beam to be transmitted through one containing chamber of the liquid sample pool, and another part of the test light beam to be transmitted through another containing chamber;

Receiving the light beams transmitted through the two containing chambers, wherein the light beam transmitted through the containing chamber to which the liquid sample to be tested is added forms a sample signal, and the light beam transmitted through the containing chamber to which the liquid sample to be tested is not added forms a reference signal;

The spectrum information of the liquid sample to be tested is determined according to the sample signal and the reference signal.

Furthermore, the test method, before adding the liquid sample to be tested into one of the containing chambers of the liquid sample pool, further comprises:

Turning on the light emitting unit to project a test light beam parallel to the partition piece of the liquid sample pool to the liquid sample pool, and allowing part of the test light beam to be transmitted through one accommodating chamber of the liquid sample pool, and another part of the test light beam to be transmitted through another accommodating chamber;

receiving the light beams transmitted through the two accommodating chambers;

The position of the liquid sample pool is adjusted so that the intensity of the transmitted light beams received by the two containing chambers is the same.

Furthermore, the test method, wherein the spectral information of the liquid sample to be tested is determined according to the sample signal and the reference signal, comprises:

Performing Fourier transformation on the sample signal and the reference signal in the time domain to transform the sample signal and the reference signal in the frequency domain;

The sample signal in the angular frequency domain is subtracted from the reference signal to obtain an angular frequency domain spectrum of the liquid sample to be tested.

Furthermore, the test method is characterized in that, according to the sample signal and the reference signal, the spectral information of the liquid sample to be tested is determined, and further comprises:

Calculating the extinction spectrum of the liquid sample to be tested according to the angular frequency domain spectrum of the liquid sample to be tested;

The absorption spectrum of the liquid sample to be tested is calculated according to the extinction spectrum of the liquid sample to be tested.

The technical solution of the embodiment of the present invention provides a liquid sample spectrum test system, method and sample pool based on terahertz spectroscopy. The liquid sample pool includes: a sample pool body, which is a storage chamber structure with a top opening composed of a bottom plate and a side plate; a partition plate, which is located inside the sample pool body, and is connected to the bottom plate and two opposite side plates, and the partition plate partitions the sample pool body to form two storage chambers. The liquid sample pool realizes system configuration by combining two storage chambers in one sample pool. The liquid sample to be tested and the empty sample storage chamber (air) are placed in the same environment, and the test beam based on terahertz spectroscopy parallel to the partition plate can pass through the liquid sample to be tested and the air at the same time. The technical solution of the embodiment of the present invention is to set a partition plate in the sample pool body to partition the sample pool body into two storage chambers. In the actual use of the liquid sample pool, the liquid sample and the reference product can be placed in the two storage chambers respectively at the same time, and then during the test, the liquid sample and the reference product can be tested at the same time in the same environment to obtain the reference signal and the sample signal. The embodiments of the present invention solve the problems of inconsistent measurement environments and long test process when measuring reference signals and sample signals successively in the existing liquid sample spectral test. The liquid sample and the reference product are respectively placed in two containing chambers of a liquid sample pool and tested at the same time, so that the reference signal and the sample signal can be measured in the same environment, ensuring that the reference signal and the sample signal are measured synchronously, thereby ensuring the accuracy of sample measurement, effectively eliminating the interference of environmental factors, and shortening the test time and improving the test efficiency.

It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a three-dimensional structure of a liquid sample pool provided in an embodiment of the present invention;

FIG2 is a schematic diagram of the top view of the liquid sample pool shown in FIG1 ;

FIG3 is a front view of the structure of the liquid sample pool shown in FIG1 ;

FIG4 is a schematic diagram of the three-dimensional structure of a liquid sample spectrum testing system based on terahertz spectroscopy provided in an embodiment of the present invention;

FIG5 is a schematic diagram of the three-dimensional structure of another liquid sample spectrum testing system based on terahertz spectroscopy provided in an embodiment of the present invention;

6 is a schematic diagram of a test beam spot at the incident surface of a liquid sample pool of a liquid sample spectrum testing system based on terahertz spectroscopy provided by an embodiment of the present invention;

FIG7 is a flow chart of a liquid sample spectrum testing method based on terahertz spectroscopy provided in an embodiment of the present invention;

FIG8 is a flow chart of another liquid sample spectrum testing method based on terahertz spectroscopy provided in an embodiment of the present invention;

FIG. 9 is a flow chart of another method for spectral testing of liquid samples based on terahertz spectroscopy provided in an embodiment of the present invention.

DETAILED DESCRIPTION

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. It should be noted that the directional words such as "upper", "lower", "left", "right" and the like described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first", "second", etc. are only used for descriptive purposes and do not represent any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

The term “including” and its variations used in the present invention are open inclusions, that is, “including but not limited to.” The term “based on” means “based at least in part on.” The term “one embodiment” means “at least one embodiment.”

It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or interdependence.

It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

Fig. 1 is a schematic diagram of the three-dimensional structure of a liquid sample pool provided by an embodiment of the present invention. Referring to Fig. 1, the liquid sample pool 10 can be used for placing test samples and reference materials in liquid sample testing, and specifically includes a sample pool body and a partition plate 13. Among them, the sample pool body is a top-opening storage bin structure composed of a bottom plate 16 and side plates. The side plates include: side plates 14/15 connected to the partition plate 13, and side plates 17/18 not connected to the partition plate 13. The partition plate 13 is located inside the sample pool body, and is respectively connected to the bottom plate 16, the side plate 14 and the side plate 15, to partition the sample pool body to form two storage bins 11/12.

FIG2 is a schematic diagram of the top view of the liquid sample pool shown in FIG1. As shown in FIG2, in the actual manufacturing process of the liquid sample pool 10, the size of the sample pool body, that is, the size _L1 of the side panel 14/15 connected to the partition piece 13 and the size _L2 of the side panel 17/18 not connected to the partition piece 13 are set. Here, the sizes _L1 and _L2 are the widths of the side panels. Those skilled in the art can set the numerical values of the sizes _L1 and _L2 according to the prior art, the test conditions and test requirements during the liquid sample test, and the manufacturing cost. For example, the size _L1 of the side panel 14/15 can be set to 20 mm; the size _L2 of the side panel 17/18 can be set to 50 or 100 mm.

In the liquid sample test, the liquid sample to be tested and the reference product need to be tested separately to obtain two signals: reference signal and sample signal. As shown in FIG2 , it can be seen that the partition sheet 13 separates the sample pool body into a containing chamber 11 and a containing chamber 12, and then the two containing chambers are configured in one sample pool. The sample to be tested and the reference product can be placed in the two containing chambers respectively and tested at the same time.

It is understandable that, during the liquid sample test, there are differences in the signals of the same sample obtained by testing in different environments, that is, changes in the environment will bring errors to the liquid sample test results. In the liquid sample test, the reference product can be selected as air, that is, the storage bin where the reference product is placed is in an empty storage bin state. In this state, the liquid sample to be tested and the empty sample storage bin (air) are placed in the same environment, and signals of different samples (liquid sample to be tested and air) under the same environment can be obtained. As shown in Figure 1, during the liquid sample test, optionally, the test light beam can be transmitted into the liquid sample pool 10 by the side plate 14 configured by the liquid sample pool 10, part of the test light beam passes through the storage bin 11, tests the liquid sample to be tested, transmits from the side plate 15, and emits the sample signal; part of the test light beam passes through the storage bin 12 to test the air, transmits from the side plate 15, and emits the reference signal. It should be noted that the specific implementation method provided in this embodiment is only one of the ways in which the present invention can be applied. For example, the side panel through which the test light beam enters the liquid sample pool 10 can be the side panel 14 or the side panel 15. The two storage chambers are used to place the samples to be tested or the air (empty storage chamber state) during the test process. This can be determined according to the test environment, test conditions and actual test requirements of the personnel implementing the liquid sample test at this time. The embodiment of the present invention is not limited here.

During the liquid sample test, the test light beam transmits the liquid sample pool 10, and a signal is emitted from the side panel on the other side of the sample pool. The material selection of the sample pool will also affect the quality of the reference signal and the sample signal. When the liquid sample to be tested is an acidic or alkaline liquid, which can cause corrosion to the sample pool, the material of the sample pool should be considered. Optionally, polyethylene, polystyrene or jgs3 quartz can be used as the material for making the liquid sample pool 10. As shown in Figure 2, it can be understood that the partition piece 13 divides the sample pool body into two containing chambers. When the test light beam enters the two containing chambers, a small part of the light beam will also enter the partition piece 13. Therefore, the partition piece 13 can be made of the same material as the sample pool body to avoid the partition piece and the sample pool body being made of different materials, causing additional interference to the test results.

FIG3 is a schematic diagram of the front view structure of the liquid sample pool shown in FIG1. As shown in FIG1 and FIG3, the test beam is transmitted into the liquid sample pool 10 through the side plate 14 or the side plate 15 connected to the partition plate. FIG3 is essentially a front view of the liquid sample pool 10 in the direction of the side plate 14. The test beam is incident on the side plate 14, part of the test beam is transmitted into the containing chamber 11, part of the test beam is transmitted into the containing chamber 12, and the rest of the test beam incident on the incident surface enters the partition plate 13. It can be understood that during the liquid sample testing process, the higher the proportion of the light beam incident on the liquid sample to be tested in the test beam incident on the side plate 14, the higher the utilization rate of the test beam, the more liquid samples are tested, and the higher the credibility of the test results. The area of the incident surface is the sum of the area incident on the two containing chambers and the area incident on the partition plate 13.

Continuing to refer to FIG3 , the thickness of the partition sheet 13 is d ₁ , and the width dimension of the side panel connected to the partition sheet 13 is d ₂ . Optionally, the thickness dimension d ₁ of the partition sheet 13 and the width dimension d ₂ of the side panel connected to the partition sheet 13 satisfy: d ₁ /d ₂ ≤5%. When the test light beam reaches the side panel connected to the partition sheet 13, the side panel will form a light spot as the incident surface. It can be understood that the numerical relationship between the thickness dimension d ₁ of the partition sheet 13 and the width dimension d ₂ of the side panel connected to the partition sheet 13 is essentially the numerical relationship between the thickness dimension d ₁ of the partition sheet 13 and the light spot size, where the light plate size is the light spot diameter. The ratio of the thickness dimension _d1 of the partition piece 13 to the width dimension _d2 of the side panel connected to the partition piece 13 is controlled at or below 5%, thereby reducing the proportion of the test beam incident on the partition piece 13 in the test beam incident on the side panel, improving the test beam utilization rate, the amount of the tested liquid sample, and the reliability of the test results. Exemplarily, the width dimension _d2 of the side panel connected to the partition piece 13 is 200 mm, and the width dimension _d2 of the partition piece is less than or equal to 10 mm; the width dimension _d2 of the side panel connected to the partition piece 13 is 100 mm, and the width dimension _d2 of the partition piece is less than or equal to 5 mm.

It should be noted that this embodiment provides one of the specific implementations that can be realized by the liquid sample pool 10, and provides an optional solution for the selection of the material of the liquid sample pool 10, the numerical relationship between the thickness _d1 of the partition piece 13 and the width dimension _d2 of the side panel connected to the partition piece 13, but is not limited to this.

An embodiment of the present invention provides a liquid sample pool. The liquid sample pool is configured with a partition sheet to partition the sample pool body to form two containing chambers. The sample to be tested and the reference product can be placed in the two containing chambers respectively, and can be tested simultaneously in the same environment. During the liquid sample testing process, the test light beam enters the liquid sample pool, and the liquid sample to be tested and the reference product in the same environment can be tested simultaneously to obtain a reference signal and a sample signal.

The technical solution of the embodiment of the present invention is to configure a partition sheet in the sample pool to partition a liquid sample pool into two containing chambers, and the two containing chambers can be used to place liquid samples and reference products respectively, so that the liquid samples and reference products can be tested at the same time in the same environment, thereby solving the problem of measuring the reference signal and the sample signal in sequence in the liquid sample spectral test, and the inaccurate test signal caused by the environmental change and the time-consuming test process. The reference signal and the sample signal are measured in the same environment, which improves the credibility of the test results, and has the technical effect of shortening the test time, thereby improving the test efficiency.

Fig. 4 is a schematic diagram of the three-dimensional structure of a liquid sample spectrum testing system based on terahertz spectroscopy provided by an embodiment of the present invention. The testing system includes the above-mentioned liquid sample pool.

As shown in FIG. 4 , the liquid sample spectrum testing system 20 includes: a liquid sample pool 10 , a light emitting unit 21 and a light receiving unit 22 .

As shown in Figures 1 and 4, the liquid sample pool 10 is placed between the light emitting unit 21 and the light receiving unit 22. During the liquid sample spectrum test, the light emitting unit 21 projects a test beam based on the terahertz spectrum that is parallel to the partition plate 13 of the liquid sample pool 10. The test beam reaches the liquid sample pool 10, and part of the test beam is transmitted by a storage chamber 11 of the liquid sample pool 10, and part of the test beam is transmitted by another storage chamber 12. The light beam transmitted by the liquid sample pool 10 reaches the light receiving unit 22, and the light receiving unit 22 receives the signal. The test beam selects the terahertz time domain spectrum, and the reference signal and the sample signal will be separated in the time domain. Only one light receiving unit 22 is required. The type of test beam can be selected according to the actual test needs of the tester. For example, time domain waves such as microwaves can be selected, and the reference signal and the sample signal will be separated in the time domain.

FIG5 is a schematic diagram of the three-dimensional structure of another liquid sample spectrum testing system based on terahertz spectroscopy provided by an embodiment of the present invention. During the liquid sample spectrum testing process, the tester takes into account the test environment, the type of sample to be tested, and the placement of each component in the liquid sample spectrum testing system, which will affect the credibility of the signal obtained by the liquid sample spectrum testing system 20. As shown in FIG5 , a light amplifying unit 23 can be set between the light emitting unit 21 and the liquid sample pool 10 to amplify the test light beam projected by the light emitting unit 21 to ensure the quality of the test light beam reaching the liquid sample pool 10. After the light emitting unit 21 projects the test light beam, it is amplified by the light amplifying unit 23, and the size of the test light beam changes. Optionally, the size of the test light beam amplified by the light beam amplifying unit 23 is greater than or equal to 10 mm, and the quality of the test light beam is guaranteed.

FIG6 is a schematic diagram of a test beam spot at the incident surface of a liquid sample pool of a liquid sample pool based on terahertz spectroscopy provided by an embodiment of the present invention. As shown in FIG6 , a test beam parallel to the partition sheet reaches a side panel connected to the partition sheet. At this time, the side panel on which the test beam is projected is the incident surface, and the size is D ₁ . The test beam forms a spot on the incident surface, and the size is D ₁ . Here, the size D ₁ is the width of the side panel on which the test beam is projected, and the size D ₁ is the diameter of the spot formed by the test beam on the incident surface.

Continuing to refer to FIG6 , the incident surface size D ₁ is larger than the spot size D ₂ , so that the test beam can be projected entirely on the incident surface, and then pass through the side plate of the liquid sample pool to enter the liquid sample pool, without causing waste of the test beam. It can be understood that the incident surface size D ₁ is larger than the spot size D ₂ , so that the test beam can be projected entirely on the incident surface. However, when the incident surface size D ₁ is too large, so that D ₁ /2＞D ₂ , the spot formed by the test beam on the incident surface cannot cover more than half of the incident surface, that is, it cannot test more than half of the liquid sample, which will result in too few liquid samples to be tested by the test beam, and will reduce the credibility of the liquid sample spectral signal. Therefore, the incident surface size D ₁ cannot be too large. When D ₁ /2＜D ₂ , that is, D ₁ ＜2D ₂ , more liquid samples can be tested, the credibility of the liquid sample spectral signal is improved, and the obtained spectral signal can better represent this type of sample.

Taking all factors into consideration, the size _D1 of the incident surface of the liquid sample pool and the size _D2 of the spot formed by the test beam on the incident surface can be _D2 ＜ _D1 ＜ _2D2 , thereby ensuring the credibility of the liquid sample spectral signal and not causing waste of the test beam. It should be noted that the size relationship between the incident surface size _D1 and the spot size _D2 of the liquid sample spectral test provided in the embodiment of the present invention is one that can be implemented by the liquid sample spectral test system. In the actual implementation process, it can be determined according to the test environment, test conditions and actual test requirements of the person implementing the liquid sample test at this time, and the embodiment of the present invention does not limit it here.

An embodiment of the present invention provides a liquid sample spectrum testing system 20 based on terahertz spectroscopy, which can be applied to scenarios where liquid samples are tested. The liquid sample pool 10 is placed between a light emitting unit 21 and a light receiving unit 22. During the liquid sample spectrum testing process, the light emitting unit 21 projects a test light beam based on terahertz spectroscopy that is parallel to the partition plate 13 of the liquid sample pool 10. The test light beam reaches the liquid sample pool 10, part of the test light beam is transmitted by a receiving chamber 11 of the liquid sample pool 10, and part of the test light beam is transmitted by another receiving chamber 12. The light beam transmitted by the liquid sample pool 10 reaches the light receiving unit 22, and the light receiving unit 22 receives the reference signal and the sample signal, and the two signals are separated in the time domain.

The technical solution of the embodiment of the present invention is to configure a partition sheet in the sample pool to partition a liquid sample pool into two containing chambers, and the two containing chambers can be used to place liquid samples and reference products respectively. During the spectral test of the liquid sample, a test light beam based on terahertz spectroscopy is transmitted into the liquid sample pool from the side plate connecting the liquid sample pool and the partition sheet, and the liquid sample and the reference product in the same environment are tested at the same time. The reference signal and the sample signal are transmitted from the side plate on the other side of the liquid sample pool to reach the light receiving unit. The embodiment of the present invention solves the problem of measuring the reference signal and the sample signal in sequence, the inaccurate test signal caused by the environmental change and the time-consuming test process in the spectral test of the liquid sample, and achieves the technical effect of measuring the reference signal and the sample signal in the same environment, thereby improving the credibility of the test result and shortening the test time, thereby improving the test efficiency.

Fig. 7 is a flow chart of a liquid sample spectrum testing method based on terahertz spectroscopy provided by an embodiment of the present invention. The method can be executed by a liquid sample spectrum testing system based on terahertz spectroscopy provided by an embodiment of the present invention.

As shown in FIG. 7 , a liquid sample spectrum testing method based on terahertz spectroscopy provided by an embodiment of the present invention includes:

S110, adding a liquid sample to be tested into one of the containing chambers of the liquid sample pool.

The liquid sample pool includes a sample pool body and a partition plate. The partition plate is located inside the sample pool body and is connected to the bottom plate and two opposite side plates respectively, so as to partition the sample pool body into two containing chambers. One containing chamber can be used to place the liquid sample to be tested, and the other containing chamber does not add the sample.

S120, turning on the light emitting unit, projecting a test beam based on terahertz spectrum parallel to the partition piece of the liquid sample pool to the liquid sample pool, and allowing part of the test beam to be transmitted through one containing chamber of the liquid sample pool, and another part of the test beam to be transmitted through another containing chamber.

During the liquid sample spectrum test, the light emitting unit emits terahertz to the liquid sample pool, part of the terahertz is transmitted through the container with the liquid sample to be tested, and the other part of the terahertz is transmitted through the empty container. The test beam based on the terahertz spectrum tests the liquid sample to be tested and the air at the same time.

S130, receiving light beams transmitted through the two containing chambers, wherein the light beam transmitted through the containing chamber to which the liquid sample to be tested is added forms a sample signal, and the light beam transmitted through the containing chamber to which the liquid sample to be tested is not added forms a reference signal.

When testing the spectrum of a liquid sample, a reference signal and a sample signal are required. The reference signal can be obtained by transmitting the test light beam through an empty container; the sample signal can be obtained by transmitting the test light beam through a container to which the liquid sample to be tested is added.

S140: Determine spectral information of the liquid sample to be tested according to the sample signal and the reference signal.

During the liquid sample spectrum test, the test results obtained are: the sample signal and the reference signal are terahertz time domain spectrum signals. The two signals can be processed to obtain the spectrum signal of the liquid sample.

As shown in FIG8 , an embodiment of the present invention provides a flow chart of another method for spectrum testing of liquid samples based on terahertz spectroscopy. Before executing the method shown in FIG7 , the method adds a preparation process of the test system in the spectrum testing of liquid samples. The method may include the following steps:

S101, turning on the light emitting unit, projecting a test light beam parallel to the partition piece of the liquid sample pool to the liquid sample pool, and making part of the test light beam transmitted through one containing chamber of the liquid sample pool, and another part of the test light beam transmitted through another containing chamber.

During the spectrum test of the liquid sample pool, the test beam based on terahertz spectroscopy is partially transmitted by one container and partially transmitted by another container to obtain a reference signal and a sample signal. During the signal processing process, the intensity of the signal will affect the accuracy of the processing result. Therefore, ensuring that the light intensity of the test beam transmitted by the two containers is roughly equal can obtain a higher quality reference signal and sample signal.

Before adding the liquid sample to be tested, the empty liquid sample pool may be tested to ensure that the intensity of the light beams transmitted by the two containing chambers is approximately equal.

S102, receiving the light beams transmitted through the two accommodating chambers.

The test light beam based on terahertz spectroscopy transmits the two containing chambers of the liquid sample pool and emits two light beams, and the light intensity of the two light beams can represent the light amount of the test light beam transmitted to the two containing chambers of the liquid sample pool at this time.

S103, adjusting the position of the liquid sample pool so that the intensity of the transmitted light beams received by the two containing chambers is the same.

According to the received light beams transmitted through the two storage chambers, the light intensity can be compared and the position of the liquid sample pool can be adjusted to adjust the light intensity of the light beams transmitted through the two storage chambers to ensure that the light intensity of the test light beams transmitted by the two storage chambers is roughly equal. For example, the center of the spot of the test light beam projected onto the incident surface is projected as close to the liquid sample pool partition as possible to ensure that the light amount of the light beams entering the two storage chambers is roughly equal.

S110, adding a liquid sample to be tested into one of the containing chambers of the liquid sample pool.

S120, turning on the light emitting unit, projecting a test beam based on terahertz spectrum parallel to the partition piece of the liquid sample pool to the liquid sample pool, and allowing part of the test beam to be transmitted through one containing chamber of the liquid sample pool, and another part of the test beam to be transmitted through another containing chamber.

S130, receiving light beams transmitted through the two containing chambers, wherein the light beam transmitted through the containing chamber to which the liquid sample to be tested is added forms a sample signal, and the light beam transmitted through the containing chamber to which the liquid sample to be tested is not added forms a reference signal.

S140: Determine spectral information of the liquid sample to be tested according to the sample signal and the reference signal.

As shown in FIG9 , a flow chart of another method for spectral testing of liquid samples based on terahertz spectroscopy provided by an embodiment of the present invention is shown. The method is based on the method shown in FIG7 , and S140 is refined. The method may include the following steps:

S110, adding a liquid sample to be tested into one of the containing chambers of the liquid sample pool.

S120, turning on the light emitting unit, projecting a test beam based on terahertz spectrum parallel to the partition piece of the liquid sample pool to the liquid sample pool, and allowing part of the test beam to be transmitted through one containing chamber of the liquid sample pool, and another part of the test beam to be transmitted through another containing chamber.

S130, receiving light beams transmitted through the two containing chambers, wherein the light beam transmitted through the containing chamber to which the liquid sample to be tested is added forms a sample signal, and the light beam transmitted through the containing chamber to which the liquid sample to be tested is not added forms a reference signal.

S141, performing Fourier transformation on the sample signal and the reference signal in the time domain to transform the sample signal and the reference signal in the frequency domain.

The reference signal and sample signal are time domain signals, which can be converted from time domain signals to angular frequency domain form through Fourier transform. The specific formula is as follows:

Where ω is the angular frequency, E(ω) is the terahertz frequency-domain electric field, E(t) is the terahertz time-domain electric field, A(ω) is the frequency-domain amplitude, and φ(ω) is the frequency-domain phase.

S142, subtracting the sample signal in the angular frequency domain from the reference signal to obtain an angular frequency domain spectrum of the liquid sample to be tested.

The sample signal and reference signal in the time domain are converted into the sample signal and reference signal in the angular frequency domain through Fourier transformation, and the angular frequency, frequency domain amplitude, and frequency domain phase of the sample signal and the reference signal can be obtained at the same time. The sample signal in the angular frequency domain is essentially the superposition of the terahertz spectrum of the liquid sample to be tested and the air. The spectral information of the liquid sample to be tested can be obtained by subtracting the sample signal from the reference signal obtained by the terahertz spectrum through the air.

S143. Calculate the extinction spectrum of the liquid sample to be tested according to the angular frequency domain spectrum of the liquid sample to be tested.

The processed angular frequency domain spectra of the sample signal and the reference signal: angular frequency ω, terahertz frequency domain electric field E(ω), terahertz time domain electric field E(t), frequency domain amplitude A(ω), frequency domain phase φ(ω), are further processed to obtain n (refractive index of the sample) and κ (extinction coefficient of the sample). The specific formula is as follows:

Where n is the refractive index of the sample, κ is the extinction coefficient of the sample, d is the thickness of the sample, c is the speed of light in a vacuum, _φs (ω) is the frequency domain phase of the sample signal, _φr (ω) is the frequency domain phase of the reference signal, _As (ω) is the frequency domain amplitude of the sample signal, and _Ar (ω) is the frequency domain amplitude of the reference signal.

S144. Calculate the absorption spectrum of the liquid sample to be tested according to the extinction spectrum of the liquid sample to be tested.

The extinction coefficient and angular frequency of the processed liquid sample can be further processed to obtain α, which is the absorption coefficient of the sample. The formula is as follows:

Where κ is the extinction coefficient of the sample, α is the absorption coefficient of the sample, and c is the speed of light in a vacuum.

The embodiment of the present invention provides a liquid sample spectrum testing method based on terahertz spectroscopy, which can be applied to the liquid sample spectrum testing process. By providing a method for obtaining a liquid sample spectrum signal, a method for debugging the liquid sample spectrum testing process before testing, and a method for processing a time domain signal after obtaining the liquid sample spectrum signal, the reference signal and the sample signal are measured simultaneously, so that the test environment of the two signals is the same, the credibility of the liquid sample spectrum signal is improved, and the test time is shortened.

Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (9)

1. A liquid sample cell, comprising:

the body of the sample pool, the sample cell body is of a containing bin structure with an opening at the top and formed by a bottom plate and a side plate;

The separation sheet is positioned inside the sample cell body and connected with the bottom plate and the two opposite side plates, and the separation sheet separates the sample cell body to form two accommodating bins;

The thickness dimension d ₁ of the partition sheet and the width dimension d ₂ of the side plate connected to the partition sheet satisfy: d ₁/d₂ is less than or equal to 5 percent.

2. The liquid sample cell according to claim 1, wherein the partition sheet is made of the same material as the cell body.

3. A terahertz spectrum based liquid sample spectrum test system, characterized by comprising the liquid sample cell according to any one of claims 1-2, further comprising a light emitting unit, a light beam amplifying unit, and a light receiving unit, the liquid sample cell being for being interposed between the light emitting unit and the light receiving unit;

The light emission unit is used for projecting a test light beam based on terahertz spectrum, which is parallel to the partition sheet of the liquid sample cell, to the liquid sample cell, and enabling part of the test light beam to be transmitted by one accommodating bin of the liquid sample cell and the other part of the test light beam to be transmitted by the other accommodating bin;

the light receiving unit is used for receiving the light beams transmitted by the two accommodating bins;

the size of the test light beam amplified by the light beam amplifying unit is greater than or equal to 10mm;

The size D ₁ of the incidence surface of the liquid sample cell and the size D ₂ of the light spot formed by the test light beam on the incidence surface satisfy the following relation: d ₂＜D₁＜2D₂.

4. A test system according to claim 3, wherein the number of light receiving units is one, the light receiving units receiving light beams projected through two receptacles of the liquid sample cell simultaneously.

5. A test system according to claim 3, wherein the beam amplifying unit is located between the light emitting unit and the liquid sample cell, the beam amplifying unit being adapted to amplify the test beam projected by the light emitting unit.

6. A method for testing a spectrum of a liquid sample based on terahertz spectrum, which is applied to the liquid sample spectrum testing system based on terahertz spectrum according to any one of claims 3 to 5, and comprises:

Adding a liquid sample to be tested into one of the accommodating bins of the liquid sample pool;

Starting a light emission unit, projecting a test light beam based on terahertz spectrum parallel to a partition sheet of the liquid sample cell to the liquid sample cell, and enabling part of the test light beam to be transmitted by one accommodating bin of the liquid sample cell and the other part of the test light beam to be transmitted by the other accommodating bin;

Receiving the light beams transmitted through the two accommodating chambers, wherein the light beams transmitted through the accommodating chambers added with the liquid sample to be tested form sample signals, and the light beams transmitted through the accommodating chambers not added with the liquid sample to be tested form reference signals;

And determining spectral information of the liquid sample to be tested according to the sample signal and the reference signal.

7. The method of testing according to claim 6, further comprising, prior to adding the liquid sample to be tested in one of the receptacles of the liquid sample cell:

Starting a light emission unit, projecting a test light beam based on terahertz spectrum parallel to a partition sheet of the liquid sample cell to the liquid sample cell, and enabling part of the test light beam to be transmitted by one accommodating bin of the liquid sample cell and the other part of the test light beam to be transmitted by the other accommodating bin;

Receiving the light beams transmitted through the two accommodating bins;

and adjusting the positions of the liquid sample tanks so that the received transmitted light beam intensities of the two accommodating bins are the same.

8. The method of testing according to claim 6, wherein determining spectral information of a liquid sample to be tested from the sample signal and the reference signal comprises:

Performing Fourier transformation on the sample signal and the reference signal in the time domain, and changing the sample signal and the reference signal in the angular frequency domain;

And subtracting the sample signal in the angular frequency domain from the reference signal to obtain the angular frequency domain spectrum of the liquid sample to be tested.

9. The method of testing according to claim 6, wherein determining spectral information of a liquid sample to be tested based on the sample signal and the reference signal, further comprises:

Calculating an extinction spectrum of the liquid sample to be tested according to the angular frequency domain spectrum of the liquid sample to be tested;

And calculating the absorption spectrum of the liquid sample to be tested according to the extinction spectrum of the liquid sample to be tested.