Terahertz spectrum detection device for herbicide spots

Abstract

The utility model discloses a terahertz spectrum detection device for herbicide spots. The terahertz spectrum detection device comprises a base, a fixed platform, a movable platform, a motor I, a motor II, an X-axis linear module, a sample holder, a Y-axis linear module and a probe, according to the utility model, by utilizing the motor and the linear module, the sample table can accurately move according to the number of samples, so that a plurality of samples can be measured at one time, and the requirement of measuring a plurality of samples is met. Besides, by adjusting the position of the probe, the angle and the distance of the probe can be adjusted, and a more accurate detection effect can be obtained.

Description

TECHNICAL FIELD

[0001] The utility model relates to physical evidence inspection equipment field, concretely relates to a terahertz spectrum detection device of herbicide stain. BACKGROUND

[0002] Terahertz (Terahertz) radiation is the electromagnetic radiation whose wave band is between microwave and infrared, and its frequency is 0.1~10THz (1THz=10 12 Hz). The THz band contains important information such as the spatial conformation of biological macromolecules that other electromagnetic wave bands cannot detect, which can directly reflect the function. The energy of THz wave is low, and it is not easy to damage the detected object, so it is an effective nondestructive testing method. At the same time, terahertz wave has good penetration, and can penetrate many non-polar materials such as crystals, plastics and paper, so it can be used to detect objects with packaging and identify internal material information. After years of research and exploration, terahertz technology has been applied in many fields, such as security inspection, biological medicine, material science, wireless communication, agricultural product detection, etc.

[0003] Herbicide is widely used in the prevention and control of harmful plants, and low toxicity herbicide is widely circulated in the market. Because of its characteristics of easy to buy and not real name, herbicide has gradually become the main source of toxic substances in the case of putting in danger. There may be herbicide stains on various objects on the scene, and timely discovery of these stains and extraction to the laboratory for further detection can link the related scenes and be beneficial to the case investigation.

[0004] However, the current herbicide stain terahertz detection device cannot completely meet the needs of accurate measurement of multiple samples at one time. UTILITY MODEL CONTENTS

[0005] In view of the defects of the prior art, the utility model aims at providing a terahertz spectrum detection device for herbicide stain.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A terahertz spectrum detection device for herbicide stain, comprising a base, a fixed platform, a movable platform, a motor one, a motor two, an X-axis linear module, a sample holder, a Y-axis linear module and a probe;

[0008] The fixed platform is fixed on the base, and the X-axis linear module is arranged on the fixed platform. The movable platform is arranged on the fixed platform and connected to the X-axis linear module. The X-axis linear module is used to drive the movable platform to move linearly along the X-axis direction. The X-axis linear module is connected to the motor one, and the motor one is used to provide power for the X-axis linear module.

[0009] The movable platform is provided with a sample holder, and the middle of the sample holder is hollowed out;

[0010] The movable platform is made of black plastic, and the movable platform is provided with a Y-axis linear module, the sample holder is connected to the Y-axis linear module, and the Y-axis linear module is used for driving the sample holder to move linearly along the Y-axis direction; the Y-axis linear module is connected to the second motor, and the second motor is used for providing power for the Y-axis linear module;

[0011] The probe is located above the movable platform and is connected to the base.

[0012] Further, the bottom corners of the base are provided with anti-skid feet.

[0013] Further, the top of the sample holder is provided with a fixed clamp on each side.

[0014] Further, the detection device further comprises a cover plate, and the cover plate is used for being placed in the middle hollowed-out area of the sample holder and shielding the middle hollowed-out area of the sample holder.

[0015] Further, the probe is connected to the base through a connecting rod; the connecting rod comprises a connecting rod one and a connecting rod two, the upper end of the connecting rod one is connected to the probe, the lower end of the connecting rod one is rotatably connected to the upper end of the connecting rod two through a universal ball head, and the lower end of the connecting rod two is connected to the base.

[0016] Further, the detection device further comprises a dust cover, the top of the dust cover is provided with an opening corresponding to the sample holder, and the side of the dust cover is provided with a dust cover door which can be opened and closed; the dust cover is used for covering the movable platform and the sample holder inside, and the probe is located above the dust cover.

[0017] Still further, the bottom edge of the dust cover is circular, a circular guide rail matched with the bottom edge of the dust cover is arranged on the base, and the bottom edge of the dust cover is located in the circular guide rail; when the dust cover door rotates circumferentially, the bottom edge thereof moves along the circular guide rail.

[0018] Still further, the side of the dust cover is provided with two adjacent dust cover doors which can be circumferentially rotatable and separated or combined.

[0019] The beneficial effects of the utility model lie in that, in the utility model, the motor and the linear module are used, the sample table can be accurately moved according to the number of samples, a plurality of samples can be measured at a time, and the need of measuring a plurality of samples is met. In addition, the angle and distance of the probe are adjusted through the adjustment of the position of the probe, which helps to obtain more accurate detection effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 This is a right-side cross-sectional view of the detection device in Embodiment 1 of this utility model (without dust cover and cover plate);

[0021] Figure 2 This is a front sectional view of the detection device in Embodiment 1 of this utility model (without dust cover and cover plate);

[0022] Figure 3 This is a right-side cross-sectional view of the detection device in Embodiment 1 of this utility model (with a dust cover and a cover plate, the dust cover is open);

[0023] Figure 4 This is a right-side cross-sectional view of the detection device in Embodiment 1 of this utility model (with a dust cover and a cover plate, the dust cover is closed);

[0024] Figure 5 The transmittance curves of paper sheets soaked in different concentrations of herbicide No. 1 in Embodiment 2 of this utility model;

[0025] Figure 6 The results are terahertz time-domain imaging of paper pieces soaked in different concentrations of herbicide No. 2 in Embodiment 2 of this utility model. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to this embodiment.

[0027] Example 1

[0028] This embodiment provides a terahertz spectral detection device for herbicide stains, such as... Figures 1-4 As shown, it includes a base 1, anti-slip feet 2, fixed platform 3, movable platform 4, motor one 5, motor two 6, X-axis linear module 7, sample rack 8, fixing clamp 9, Y-axis linear module 10, cover plate 11, probe 12, connecting rod one 13, connecting rod two 14, ball head 15, dust cover 16, circular guide rail 17, and dust cover door 18.

[0029] The base 1 has anti-slip feet 2 at its four bottom corners to maintain the overall stability of the device and ensure the reliability of the imaging results.

[0030] The base 1 is fixed to a fixed platform 3 with screws in the middle. An X-axis linear module 7 is provided on the fixed platform 3. The movable platform 4 is located on the fixed platform 3 and connected to the X-axis linear module 7. The X-axis linear module 7 is used to drive the movable platform 4 to move linearly along the X-axis direction. The X-axis linear module 7 is connected to a motor 5. The motor 5 is used to provide power to the X-axis linear module.

[0031] The movable platform is provided with a sample holder 8, the sample holder 8 is hollow in the middle and is provided with a fixing clamp 9 on each side. According to the area of the measurement carrier, small samples can be directly placed on the sample holder 8, and medium and large samples are placed on the sample holder 8 and can be fixed by the fixing clamps 9 on both sides. In this embodiment, the fixing clamp 9 is a thin metal sheet, which is curved in the middle and has elasticity, one end of the fixing clamp 9 is fixed on the sample holder 8 by a screw, and the other end can be lifted upward for placing the sample.

[0032] The movable platform 4 is made of black plastic, and the movable platform 4 is provided with a Y-axis linear module 10, the sample holder 8 is connected to the Y-axis linear module 10, and the Y-axis linear module 10 is used to drive the sample holder 8 to move linearly along the Y-axis direction; the Y-axis linear module 10 is connected to the motor two 6, and the motor two 6 is used to provide power for the Y-axis linear module 10.

[0033] It should be noted that the X-axis linear module and the Y-axis linear module can adopt a common screw block module, and the screw is driven to rotate by a motor, so as to drive the block and the components connected with the block to move linearly.

[0034] When the sample stage needs to move along the X-axis direction, the motor one 5 is started by the motor controller, and the movable platform 4 is driven to move along the X-axis direction by the X-axis linear module, so as to drive the sample holder 8 to move along the X-axis direction. When the sample stage needs to move along the Y-axis direction, the motor two 6 is started by the motor controller, and the sample holder 8 is driven to move along the Y-axis direction by the Y-axis linear module. By pre-setting the step length of the motor one 5 and the motor two 6 in the motor controller, the sample stage can move at a pre-set step length, so as to realize precise step control and precise selection of the sample measurement area range.

[0035] Further, in this embodiment, a cover plate 11 is further included, which is used to be placed in the hollow region in the middle of the sample holder 8 and to shield the hollow region in the middle of the sample holder 8.

[0036] The probe 12 is located above the movable platform 4 and is connected to the base 1 through a connecting rod; the connecting rod includes a connecting rod one 13 and a connecting rod two 14, the probe 12 is connected to the upper end of the connecting rod one 13, the lower end of the connecting rod one 13 is rotatably connected to the upper end of the connecting rod two 14 through a universal ball head 15, and the lower end of the connecting rod two 14 is connected to the base 1. During the measurement process, the probe 12 can be moved left and right or up and down within a certain range by rotating the connecting rod one.

[0037] Further, the detection device of the embodiment further comprises a dust cover 16, the top of the dust cover 16 is provided with an opening corresponding to the sample holder 8, and the side of the dust cover 16 is provided with a dust cover door 18 which can be opened and closed; the dust cover 16 is used to cover the movable platform 4 and the sample holder 8 inside and the probe 12 is located above the dust cover 16.

[0038] In the embodiment, the bottom edge of the dust cover 16 is circular, the base 1 is provided with a circular guide rail 17 matching the bottom edge of the dust cover 16, and the bottom edge of the dust cover 16 is located in the circular guide rail 17; when the dust cover door 18 rotates circumferentially, the bottom edge thereof moves along the circular guide rail 17.

[0039] In the embodiment, the side of the dust cover is provided with two adjacent dust cover doors 18 which can rotate circumferentially to separate or combine; when observation and sample placement are needed, the dust cover doors are rotated to open the internal space of the dust cover; when long-time measurement or long-term non-use of the detection device is needed, the dust cover doors are rotated to make the dust cover completely surround the movable platform and the sample holder.

[0040] The working principle of the above detection device is that:

[0041] The moving step length of the motor one 5 and the motor two 6 is set in advance in the motor controller, so as to accurately control the moving distance of the sample holder in the X-axis and Y-axis directions, accurately select the measurement area of the sample, and thus continuously measure multiple samples at one time and obtain more accurate detection results. Through the fixed clamps 9 on the sample holder 8, the measurement stability of multiple samples on a large-area sample carrier can be ensured.

[0042] The sample carrier carrying the sample is placed on the sample holder 8, and the samples are all located in the middle hollow area of the sample holder 8. The top of the sample holder 8 is provided with a cover plate 11. When the cover plate 11 is manually opened, the sample holder is in a middle hollow form, and the cover plate 11 can also be closed according to needs. For a large-area sample carrier such as paper and cloth, one side thereof can be fixed in the fixed clamps 9 on both sides.

[0043] According to the sample condition, the terahertz transmission mode or the terahertz reflection mode is selected. During detection, the probe receives the terahertz wave which passes through the sample and reflects the sample information, and measures the material composition of the sample. The terahertz time-domain imaging result of the sample can also be obtained. The transmission and reflection mechanisms are built-in in the terahertz main machine (not shown in the figure). At the same time, through the design of the dust cover 16, the influence of dust in the external environment can be effectively avoided.

[0044] Embodiment 2

[0045] The embodiment provides a detection example of herbicide stains on various objects by using the terahertz spectrum detection device in embodiment 1. Paper pieces soaked in herbicides with different concentrations can be used to measure samples in a transmission mode, and concentration-related information is reflected on the transmittance curve. At the same time, the paper pieces soaked in herbicides with different concentrations are used for time-domain spectral imaging in a reflection mode.

[0046] The same batch of white paper is purchased, and several pieces with a size of 2cm*2cm are cut for standby. One piece is taken as a blank control sample, and No. 1 herbicide is selected to prepare gradient concentrations of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. Then, 30 pieces of the standby 2cm*2cm paper pieces are soaked in the gradient concentrations of herbicides, and after being soaked, they are taken out, laid flat, and dried for 24 hours, and then the paper pieces are subjected to transmission spectrum detection. The test method is transmission THZ-TDS, the scanning window is 160ps, and the total scanning time is 18 minutes. The transmission spectrum detection result is shown in Table 1. Figure 5

[0047] No. 2 herbicide is selected to prepare gradient concentrations of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. A drop (0.1mL) of each gradient concentration sample is dropped on the standby 2cm*2cm paper pieces, the paper pieces are laid flat and dried for 24 hours, and then the paper pieces are directly subjected to reflection imaging detection. The test method is reflection imaging, the imaging resolution is 0.1mm, the X direction is 500 pixels (50mm), the Y direction is 1200 pixels (120mm), and the scanning window is set to 160ps. The reflection imaging detection result is shown in Table 2. Figure 6

[0048] For those skilled in the art, various corresponding changes and modifications can be given according to the above technical solutions and concepts, and all the changes and modifications should be included in the protection scope of the utility model claim.​​

Claims

1. A terahertz spectroscopic detection device for herbicide stains, characterized in that, Includes a base, a fixed platform, a movable platform, motor one, motor two, an X-axis linear module, a sample holder, a Y-axis linear module, and a probe; A fixed platform is fixed on the base, and an X-axis linear module is provided on the fixed platform. The movable platform is located on the fixed platform and connected to the X-axis linear module. The X-axis linear module is used to drive the movable platform to move linearly along the X-axis direction. The X-axis linear module is connected to a motor, which provides power to the X-axis linear module. The movable platform is equipped with a sample rack, which has a hollow center. The movable platform is made of black plastic and is equipped with a Y-axis linear module. The sample holder is connected to the Y-axis linear module, which drives the sample holder to move linearly along the Y-axis. The Y-axis linear module is connected to the second motor, which provides power to the Y-axis linear module. The probe is located above the movable platform and connected to the base.

2. The apparatus according to claim 1, characterized in that, The base has anti-slip feet at the four corners of its bottom.

3. The apparatus according to claim 1, characterized in that, The sample holder is equipped with fixing clips on both sides of its top.

4. The apparatus according to claim 1, characterized in that, It also includes a cover plate, which is used to place in the central hollow area of ​​the sample holder and to cover the central hollow area of ​​the sample holder.

5. The apparatus according to claim 1, characterized in that, The probe is connected to the base via a connecting rod; the connecting rod includes a connecting rod one and a connecting rod two, the probe is connected to the upper end of the connecting rod one, the lower end of the connecting rod one is rotatably connected to the upper end of the connecting rod two via a universal ball joint, and the lower end of the connecting rod two is connected to the base.

6. The apparatus according to claim 1, characterized in that, It also includes a dust cover, the top of which has an opening corresponding to the sample holder, and the side of which has an openable dust cover door; the dust cover is used to cover the movable platform and the sample holder, and the probe is located above the dust cover.

7. The apparatus according to claim 6, characterized in that, The bottom edge of the dust cover is circular, and a circular guide rail is provided on the base to match the bottom edge of the dust cover. The bottom edge of the dust cover is located inside the circular guide rail. When the dust cover rotates circumferentially, its bottom edge moves along the circular guide rail.

8. The apparatus according to claim 6 or 7, characterized in that, The dust cover has two adjacent dust cover doors on its side, which can be rotatably separated or merged.

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