CN117405437A - Soil sample collector suitable for TDR technology - Google Patents
Soil sample collector suitable for TDR technology Download PDFInfo
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- CN117405437A CN117405437A CN202311177813.3A CN202311177813A CN117405437A CN 117405437 A CN117405437 A CN 117405437A CN 202311177813 A CN202311177813 A CN 202311177813A CN 117405437 A CN117405437 A CN 117405437A
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- soil
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- stainless steel
- central needle
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- 239000002689 soil Substances 0.000 title claims abstract description 91
- 238000005516 engineering process Methods 0.000 title claims abstract description 13
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 30
- 239000010935 stainless steel Substances 0.000 claims abstract description 30
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 37
- 235000017166 Bambusa arundinacea Nutrition 0.000 claims description 16
- 235000017491 Bambusa tulda Nutrition 0.000 claims description 16
- 241001330002 Bambuseae Species 0.000 claims description 16
- 235000015334 Phyllostachys viridis Nutrition 0.000 claims description 16
- 239000011425 bamboo Substances 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 16
- 238000005259 measurement Methods 0.000 claims description 15
- 239000004020 conductor Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 8
- 238000005303 weighing Methods 0.000 claims description 8
- 238000002360 preparation method Methods 0.000 claims description 7
- 238000004364 calculation method Methods 0.000 claims description 5
- 238000009434 installation Methods 0.000 claims description 4
- 238000002310 reflectometry Methods 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 238000004891 communication Methods 0.000 claims 1
- 239000000523 sample Substances 0.000 abstract description 21
- 238000010276 construction Methods 0.000 abstract description 3
- 238000001514 detection method Methods 0.000 abstract description 3
- 239000002699 waste material Substances 0.000 abstract description 3
- 238000001035 drying Methods 0.000 description 7
- 238000012544 monitoring process Methods 0.000 description 5
- 238000005520 cutting process Methods 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 238000005527 soil sampling Methods 0.000 description 2
- 238000012271 agricultural production Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001028 reflection method Methods 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/02—Devices for withdrawing samples
- G01N1/04—Devices for withdrawing samples in the solid state, e.g. by cutting
- G01N1/08—Devices for withdrawing samples in the solid state, e.g. by cutting involving an extracting tool, e.g. core bit
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/04—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder
- G01N5/045—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder for determining moisture content
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention provides a soil sample collector suitable for TDR technology, which comprises a collecting cylinder and a central needle body, wherein the central needle body is arranged at the central position inside the collecting cylinder, the collecting cylinder is cylindrical and is provided with a top wall and a side wall, a containing cavity is formed inside the collecting cylinder through the top wall and the side wall, the top wall of the collecting cylinder is provided with a mounting through hole, a cylindrical stainless steel sleeve is arranged outside the top wall of the collecting cylinder around the mounting through hole, the central needle body passes through the stainless steel sleeve and is arranged in the containing cavity of the collecting cylinder, and the central axis of the central needle body is mutually overlapped with the central axis of the collecting cylinder. The invention changes the original three-needle type probe into a single-needle type probe, combines the single-needle type probe with the collection cylinder with proper height and volume to prepare a new collector, so that the step of taking soil is completed while the central needle body is inserted, the waste of site construction manpower is reduced, and meanwhile, the system error caused by secondary damage to soil body and inconsistent detection position of the central needle body and soil collection position is avoided.
Description
Technical Field
The invention relates to the technical field of soil moisture measurement, in particular to a soil sample collector suitable for TDR technology.
Background
Soil moisture measurement is an actual requirement in various fields such as agricultural production, hydrologic monitoring, geotechnical engineering and the like, and the measurement method can be divided into an artificial drying method and an instrument method. The traditional manual drying method cannot acquire measurement data in time due to long drying time, but in recent years, soil moisture measuring instruments are greatly developed, and automatic on-line monitoring and on-site rapid measurement are possible. However, the dielectric method instrument can only realize the rapid measurement of the soil volume moisture content, and the mass moisture content still needs to be obtained by measuring the dry volume weight conversion of the soil through a manual drying method, so that the rapid measurement of the soil mass moisture content cannot be realized. The quality water content and the relative humidity derived from the quality water content are evaluation parameters mainly used in hydrologic monitoring, especially drought monitoring. Therefore, the rapid monitoring of the mass water content has extremely important significance.
In order to solve the problem of long experimental time of the drying method, an improved drying method using a microwave oven to replace a rapid drying oven has been proposed in recent years. However, as the microwave heating time is further verified by theory and experiment, the combined water in the soil is easily dried together to generate a systematic error when the time is incorrectly set. With the localization of the TDR soil moisture measuring technology, the rapid determination of the soil volume moisture content is possible without the need of formula calibration. Under the premise, the soil quality and water content can be rapidly measured by a TDR instrument by combining on-site ring cutter soil sampling and weighing, and the concrete method comprises the following steps:
preparing a ring cutter with a volume V of empty in advance, and weighing the mass m of the empty ring cutter Empty space The method comprises the steps of carrying out a first treatment on the surface of the Inserting a TDR probe at a required measurement site, and measuring to obtain the volume water content theta of the point V . Collecting soil sample near the measuring point by using a ring cutter prepared in advance, and weighing the soil sample with a balance with the mass of m Cutting ring ；
From m Wet soil ＝m Cutting ring -m Empty space Obtaining the mass of wet soil, and then obtaining the mass of wet soil by the formula:
mWater=vblank×θvx1g/ml to obtain the mass of water contained in the soil in the cutting ring (the density of default water is 1 g/ml);
from m Dry soil ＝m Wet soil -m Water and its preparation method The dry soil quality is obtained, so that the soil quality moisture content can be calculatedDry volume weight->
The method is complex in operation, the volume water content and the cutting ring soil sampling are required to be respectively carried out, the operation point cannot bring errors, and the accuracy of the soil quality water content is affected.
Disclosure of Invention
The invention provides a device which can be used together with a soil moisture measuring instrument by a time domain reflection method, and can be used for rapidly measuring the mass moisture content of soil on site, so that the blank of the current method for instantly measuring the mass moisture content of soil is filled.
The invention provides a soil sample collector suitable for TDR technology, which adopts the following technical scheme:
the utility model provides a be suitable for soil sample collector of TDR technique, including gathering section of thick bamboo and central needle body, the central needle body sets up the inside central point of gathering the section of thick bamboo and puts, gathers the section of thick bamboo and is cylindrical, has roof and lateral wall, makes through roof and lateral wall and gathers the inside formation of section of thick bamboo and hold the cavity, its characterized in that gathers section of thick bamboo roof and is provided with the installation through-hole, is provided with cylindrical stainless steel cover in gathering the section of thick bamboo roof outside around this installation through-hole, and the central needle body passes the stainless steel cover and sets up in gathering the holding cavity of section of thick bamboo, and the central axis of central needle body coincides each other with the central axis of gathering the section of thick bamboo.
Further, an impedance converter is arranged between the top of the central needle body and the stainless steel sleeve, the impedance converter is connected with a copper core of an inner conductor of the coaxial cable, one end of the coaxial cable is connected with the impedance converter, and the other end of the coaxial cable is connected with a soil moisture meter of a frequency domain frequency stepping system through a BNC connector.
Furthermore, the impedance converter is composed of a high polymer low conductivity material and a reducing outer conductor.
Further, the impedance converter is a hollow cylinder, the inner diameter D is equal to the outer diameter of the central needle body, and the outer diameter of the impedance converter is D; the specific calculation method of D is as follows:
wherein Z is the impedance to be converted, e is the natural constant, and epsilon is the relative dielectric constant of the selected high-molecular low-conductivity material.
Further, the stainless steel cap comprises two reducing hollow stainless steel shells, the large-diameter shells cover the outer diameter of the impedance converter, the diameter is the same as the outer diameter of the impedance converter to be Dmm, a small-diameter shell is concentrically arranged above the large-diameter shells, and the diameter of the small-diameter shell is the same as the outer diameter of the coaxial cable outer shielding conductor.
Further, the stainless steel sleeve is made of stainless steel, and is hollow and cylindrical in structure.
Further, the calculation method of the soil mass water content comprises the following steps:
s1, weighing the central needle body (4) before using measurement and recording as m Empty space The method comprises the steps of carrying out a first treatment on the surface of the Calculating to obtain the volume of the central needle body (4) as a fixed value V Collecting ；
S2, horizontally inserting the collector at a required measurement place, so that a central needle body part in the collector is tightly attached to soil, and a pipe wall part at the outer side of the collector is tightly inserted into the soil;
s3, measuring the volume water content theta of the point by using a corresponding soil moisture monitor V ；
S4, taking out a collecting cylinder filled with the soil to be tested, and measuring to obtain the total weight m of the collecting cylinder Collecting ；
S5, from m Wet soil ＝m Collecting -m Empty space Obtaining the mass of wet soil, and then obtaining the mass of wet soil by the formula:
m water and its preparation method ＝V Collecting ×θ V Obtaining the mass of water contained in soil in the collecting pipe by multiplied by 1g/ml, wherein the density of default water is 1g/ml;
s6, from m Dry soil ＝m Wet soil -m Water and its preparation method The quality of the dry soil is obtained, so that the quality water content can be calculatedDry volume weight->
In summary, the beneficial effects of the invention are as follows:
the invention changes the three-needle type probe commonly used for measuring the water content of the soil volume by the original Time Domain Reflectometry (TDR) into a single-needle type probe, and combines the probe with the acquisition cylinder with proper height and volume to prepare a new acquisition device, so that the step of taking the soil is completed when the central needle body is inserted, the waste of site construction manpower is reduced, and meanwhile, the system error caused by secondary damage to the soil body and inconsistent detection position of the central needle body and the soil acquisition position is avoided; finally, by combining the mass water content calculating method, the mass water content can be quickly calculated after on-site weighing, and the time for measuring the mass water content in the past is shortened.
Drawings
FIG. 1 is a schematic view of the assembled whole structure of the present invention;
FIG. 2 is a schematic cross-sectional view of the assembled overall structure of the present invention;
FIG. 3 is a schematic view of a three-dimensional structure of a stainless steel cap according to the present invention;
FIG. 4 is a schematic diagram of an impedance transformer according to the present invention;
FIG. 5 is a schematic view of a stainless steel jacket in a three-dimensional structure according to the present invention;
FIG. 6 is a schematic perspective view of a central needle of the present invention;
fig. 7 is a schematic perspective view of a collecting barrel according to the present invention.
The following figures are shown: 1-stainless steel caps; a 2-impedance converter; 3-stainless steel sleeve; 4-a central needle body; 5-collecting cylinder.
Detailed Description
The invention will be further described with reference to specific examples, illustrative examples and illustrations of which are provided herein to illustrate the invention, but are not to be construed as limiting the invention.
Examples: a soil sample collector suitable for TDR technology as shown in fig. 1, 2, 3, 4, 5, 6, 7.
As shown in fig. 1-2 and fig. 6-7, a soil sample collector suitable for TDR technology comprises a collecting cylinder 5 and a central needle body 4, wherein the central needle body 4 is arranged at the central position inside the collecting cylinder 5, the collecting cylinder 5 is cylindrical and provided with a top wall and a side wall, a containing cavity is formed inside the collecting cylinder 5 through the top wall and the side wall, the top wall of the collecting cylinder 5 is provided with a cylindrical stainless steel sleeve 3, the central needle body 4 passes through the stainless steel sleeve 3 and is arranged in the containing cavity of the collecting cylinder 5, and the central axis of the central needle body 4 and the central axis of the collecting cylinder 5 are mutually overlapped.
As shown in fig. 2 and 4, an impedance converter 2 is arranged between the top of the central needle body 4 and the stainless steel sleeve 3, the impedance converter 2 is composed of a high polymer low conductivity material and a variable diameter outer conductor, the impedance converter 2 is connected with a copper core of an inner conductor of a coaxial cable, one end of the coaxial cable is connected with the impedance converter 2, and the other end of the coaxial cable is connected with a TDR-type soil moisture meter through a BNC connector.
As shown in fig. 4 and 6, the impedance converter 2 is a hollow cylinder, and the material is a polymer low-conductivity material; the inner diameter D (mm) of the impedance converter 2 is equal to the outer diameter of the central needle body 4, and the outer diameter D (mm) of the impedance converter 2 is equal to the outer diameter D (mm);
wherein Z is impedance (ohm) to be converted, e is natural constant, epsilon is relative dielectric constant of the selected high-molecular low-conductivity material.
As shown in fig. 3 and 4, the stainless steel cap 1 includes two hollow stainless steel housings of varying diameters, a large-diameter housing which encloses the outer diameter of the impedance converter 2 and has the same diameter D (mm) as the outer diameter of the impedance converter 2, and a small-diameter housing which has the same diameter as the outer diameter of the coaxial cable outer shield conductor and is concentrically provided above the large-diameter housing.
As shown in fig. 5, the stainless steel sleeve 3 is made of stainless steel, and has a hollow cylindrical structure for protecting the impedance converter 2, and the connection parts of the stainless steel cap 1 and the impedance converter 2.
A method of making a sensor suitable for measuring dielectric properties of soil by the TDR method comprising the steps of:
a. the main body center needle is made of stainless steel wires, and the length of the center needle is the length of the impedance converter plus the length of the probe;
b. drilling an inner hole with the diameter the same as the diameter of the copper core in the coaxial cable and the length L2 along the center of one end of the central needle body, and fastening and connecting the copper core in the coaxial cable in a cold pressing mode after the copper core in the coaxial cable is inserted;
c. firstly, stripping the copper core with the length of L2 from the coaxial cable, inserting the copper core into a central needle body, and carrying out cold pressing and fastening;
d. peeling the coaxial cable to L1 length to expose the outer shielding layer;
e. the central needle is inserted into the impedance converter and is fastened by cold pressing at the small diameter of the impedance converter and the stainless steel cap.
The calculation method of the soil quality water content comprises the following steps:
s1, weighing the central needle body (4) before using measurement and recording as m Empty space The method comprises the steps of carrying out a first treatment on the surface of the Calculating to obtain the volume of the central needle body (4) as a fixed value V Collecting ；
S2, horizontally inserting the collector by using a manual or power-assisted means at a required measurement site, so that a TDR probe part in the collector is tightly attached to soil, and an outer pipe wall part is tightly inserted into the soil;
s3, measuring the volume water content theta of the point by using a corresponding soil moisture monitor V ；
S4, taking out a collecting cylinder filled with the soil to be tested, and measuring to obtain the total weight m of the collecting cylinder Collecting ；
S5, from m Wet soil ＝m Collecting -m Empty space Obtaining the mass of wet soil, and then obtaining the mass of wet soil by the formula:
m water and its preparation method ＝V Collecting ×θ V X1 g/ml to obtain the mass of water contained in the soil in the collection tube (the density of default water is 1 g/ml);
s6, from m Dry soil ＝m Wet soil -m Water and its preparation method The quality of the dry soil is obtained, so that the quality water content can be calculatedDry volume weight->
By adopting the method, hundreds of experimental comparison results are accumulated, and the method has good measurement accuracy.
The invention changes the three-needle type probe commonly used for measuring the water content of the soil volume by the original Time Domain Reflectometry (TDR) into a single-needle type probe, and combines the probe with the acquisition cylinder with proper height and volume to prepare a new acquisition device, so that the step of taking the soil is completed when the central needle body is inserted, the waste of site construction manpower is reduced, and meanwhile, the system error caused by secondary damage to the soil body and inconsistent detection position of the central needle body and the soil acquisition position is avoided; finally, the mass water content can be quickly calculated after on-site weighing by combining the calculation methods, so that the time required by the previous measurement step is shortened.
The foregoing has shown and described the basic principles and main features of the present invention and the advantages of the present invention. Various components mentioned in the present invention are common in the art, and it should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications can be made in the present invention without departing from the spirit and scope of the invention, which is defined in the claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (7)
1. The utility model provides a be suitable for soil sample collector of TDR technique, including gathering section of thick bamboo (5) and central needle body (4), central needle body (4) set up in the inside central point of gathering section of thick bamboo (5), gather section of thick bamboo (5) and be cylindrical, have roof and lateral wall, make the inside formation of gathering section of thick bamboo (5) hold the cavity through roof and lateral wall, a serial communication port, gathering section of thick bamboo (5) roof is provided with the installation through-hole, be provided with cylindrical stainless steel cover (3) in gathering section of thick bamboo (5) roof outside around this installation through-hole, central needle body (4) pass stainless steel cover (3) and set up in the holding cavity of gathering section of thick bamboo (5), the central axis of central needle body (4) and the central axis mutual coincidence of gathering section of thick bamboo (5).
2. The soil sample collector suitable for the TDR technology according to claim 1, wherein an impedance converter (2) is arranged between the top of the central needle body (4) and the stainless steel sleeve (3), the impedance converter (2) is connected with a copper core of an inner conductor of a coaxial cable, one end of the coaxial cable is connected with the impedance converter (2), and the other end of the coaxial cable is connected with a soil moisture meter adopting the Time Domain Reflectometry (TDR) through a BNC connector.
3. A soil sample collector suitable for TDR technology according to claim 2, characterized in that the impedance converter (2) consists of a high molecular low conductivity material and a reducing outer conductor.
4. A soil sample collector suitable for TDR technology according to claim 3, characterized in that the impedance transformer (2) is a hollow cylinder with an inner diameter D equal to the outer diameter of the central needle (4), the outer diameter of the impedance transformer (2) being D; the specific calculation method of D is as follows:
wherein Z is the impedance to be converted, e is the natural constant, and epsilon is the relative dielectric constant of the selected high-molecular low-conductivity material.
5. The soil sample collector of claim 4, wherein the stainless steel cap (1) comprises two hollow stainless steel shells with variable diameters, wherein the large-diameter shells cover the outer diameter of the impedance transformer (2), the same diameter as the outer diameter of the impedance transformer (2) is D, a small-diameter shell is concentrically arranged above the large-diameter shell, and the diameter of the small-diameter shell is the same as the outer diameter of the coaxial cable outer shielding conductor.
6. A soil sample collector suitable for TDR technology according to claim 5, characterized in that the stainless steel sheath (3) is made of stainless steel material and is of hollow cylinder structure.
7. A soil sample collector suitable for TDR technology according to any one of claims 1-6, wherein the method for calculating the water content of soil mass comprises the steps of:
s1, weighing the central needle body (4) before using measurement and recording as m Empty space The method comprises the steps of carrying out a first treatment on the surface of the Calculating to obtain the volume of the central needle body (4) as a fixed value V Collecting ；
S2, horizontally inserting the collector at a required measurement place, so that a central needle body part in the collector is tightly attached to soil, and a pipe wall part at the outer side of the collector is tightly inserted into the soil;
s3, measuring the volume water content theta of the point by using a corresponding soil moisture monitor V ；
S4, taking out a collecting cylinder filled with the soil to be tested, and measuring to obtain the total weight m of the collecting cylinder Collecting ；
S5, from m Wet soil ＝m Collecting -m Empty space Obtaining the mass of wet soil, and then obtaining the mass of wet soil by the formula: m is m Water and its preparation method ＝V Collecting ×θ V Obtaining the mass of water contained in soil in the collecting pipe by multiplied by 1g/ml, wherein the density of default water is 1g/ml;
s6, from m Dry soil ＝m Wet soil -m Water and its preparation method The dry soil quality is obtained, so that the soil quality moisture content can be calculatedDry volume weight->
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311177813.3A CN117405437A (en) | 2023-09-13 | 2023-09-13 | Soil sample collector suitable for TDR technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311177813.3A CN117405437A (en) | 2023-09-13 | 2023-09-13 | Soil sample collector suitable for TDR technology |
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| Publication Number | Publication Date |
|---|---|
| CN117405437A true CN117405437A (en) | 2024-01-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311177813.3A Pending CN117405437A (en) | 2023-09-13 | 2023-09-13 | Soil sample collector suitable for TDR technology |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117405437A (en) |
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- 2023-09-13 CN CN202311177813.3A patent/CN117405437A/en active Pending
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