CN218003158U - Soil moisture characteristic curve measuring instrument - Google Patents

Abstract

The utility model relates to an agricultural hydraulic engineering field, in particular to soil moisture characteristic curve measuring apparatu, including the probe, lead the pressure equipment, pressure acquisition device, differential pressure measuring device, the probe is porous medium's argil head, lead the pressure equipment and include the pressure tube, the inner tube is the hose, the outer tube is flexible hard tube, the end connection of inner tube has the hose connector, the protruding edge of hose connector and the end connection of outer tube, connection structure and probe connection are passed through to the one end of inner tube, pressure acquisition device includes the pressure acquisition pipe, its one end is connected with the one end that leads the pressure tube and deviates from the probe through connection structure, the other one end is connected with water inlet switch, be provided with the measurement port on the pressure acquisition pipe, the measurement port is connected with differential pressure measuring device, the utility model discloses a set up pressure tube and probe connection, the probe carries out the in-process of exchanging with soil water-logging, volume change in the pressure tube thereupon, through the volume change in the differential pressure measuring device real-time measurement, make measuring result more accurate.

Description

A Soil Moisture Characteristic Curve Measuring Instrument

technical field

The utility model relates to the technical field of agricultural water conservancy engineering, in particular to a soil moisture characteristic curve measuring instrument.

Background technique

The soil moisture characteristic curve is the most important and basic tool for studying soil moisture movement, regulating and utilizing soil water, and improving soil, and it is the theoretical basis for guiding irrigation. The matric potential or soil water suction of soil water changes with the soil water content. By measuring the corresponding soil water suction value of the soil at different water contents, and drawing a curve, such a curve is the soil moisture characteristic curve, which represents What is the relationship between the energy of soil water and the quantity of soil water. The slope of the soil moisture characteristic curve reflects the water supply capacity of the soil, that is, how much water the soil can release when the matric potential decreases by a certain amount. The effectiveness of soil moisture to plants is ultimately determined by the level of soil water potential, rather than its own water content. If the water content of the soil is measured, the matric potential value can be found according to the soil moisture soil characteristic curve, so as to judge the effective degree of the soil water content for plants. According to the characteristic curve of soil moisture, the soil moisture can be converted into soil matrix potential, and the effectiveness of soil moisture to crops can be judged according to the matrix potential. The matric potential can also be converted into water content. According to the soil moisture characteristic curve, the field water holding capacity, withering humidity and corresponding effective water range can be found. The soil moisture characteristic curve can indirectly reflect the distribution of soil pores, and can judge the soil texture and the distribution of water in the suction section. The inflection point of the curve can reflect the soil moisture state under the corresponding water content.

The existing soil moisture characteristic curve determination methods mainly include negative pressure meter method, sandy funnel method, manometer method, centrifuge method and so on. The permeability coefficient of the soil also changes with the moisture content, showing a curvilinear relationship. The easiest way to measure soil water suction in the field is the tensiometer method. The tensiometer measures the soil moisture characteristic curve. The advantage is that it can measure both the soil moisture absorption process and the soil dehydration process. The cost is low, and it can be applied to field in-situ fixed-point monitoring. in the lysimeter system.

A soil moisture tensiometer (publication number: CN2809631Y) disclosed in the prior art can measure the suction force of large buried deep soil, but because its measurement method adopts a mercury manometer, the mercury manometer cannot avoid thermal expansion due to the characteristics of mercury itself. Influenced by the principle of cold shrinkage, it is very likely to cause inaccurate measurement. Therefore, a soil moisture characteristic curve measuring instrument is needed to solve the above problems.

Utility model content

The purpose of this utility model is to solve the problem that the existing soil moisture tensiometer adopts mercury pressure gauge. Due to the characteristics of mercury itself, it cannot avoid the influence of thermal expansion and contraction principle, which may lead to inaccurate measurement readings, and provides a suction measurement range. Wide range, high precision, automatic data collection and transmission of soil moisture suction measuring instrument.

A soil moisture characteristic curve measuring instrument provided by the utility model comprises:

probe;

A pressure guide device, which includes a pressure guide tube, one end of the pressure guide tube is connected to the probe, and the other end is connected to a pressure acquisition device;

The pressure acquisition device includes: a pressure acquisition tube, one end of which is connected to the end of the pressure guiding tube away from the probe, the other end is connected to a water inlet switch, and the circumference of the pressure acquisition tube is provided with a measurement port; a differential pressure measurement device, the measurement end of which is connected to the measurement port port connection.

Preferably, the pressure guide tube includes an inner tube, the inner tube is covered with an outer tube, the two ends of the inner tube are connected with hose connectors, and the convex edge of the hose connector is connected with the end of the outer tube.

Preferably, a threaded connection sleeve is connected to the side of the hose connector away from the inner tube, and a threaded connection tube matching the threaded connection sleeve is connected to the side of the probe and the pressure collection tube close to the hose connector.

Preferably, an airtight gasket is arranged inside the threaded connection sleeve.

Preferably, the inner tube is a flexible tube, and the outer tube is a telescopic hard tube.

Preferably, the probe is a clay head.

Preferably, the differential pressure measurement device includes a differential pressure gauge, and the measurement end of the differential pressure gauge is connected to the measurement port of the pressure collection tube.

Preferably, the differential pressure gauge is connected with a paperless recorder.

Compared with the prior art, a soil moisture characteristic curve measuring instrument provided by the utility model has the beneficial effects of:

1. The utility model connects the pressure guiding tube with the probe. During the process of exchanging the probe with the water in the soil, the volume in the pressure guiding tube changes accordingly, and the real-time measurement of the volume change in the tube through the differential pressure measuring device makes the measurement result more accurate. precise.

2. The pressure guide tube of the utility model includes an inner tube and an outer tube. When in use, the length of the pressure guide tube can be adjusted according to the actual measurement requirements, so as to realize the measurement of a large buried depth, and it is possible to insert different ranges into different sections of a section at the same time The measuring instrument improves the measurement efficiency.

3. The utility model adopts the combination of paperless recorder and data processor for data collection to realize automatic data collection and reduce manpower consumption.

Description of drawings

Fig. 1 is the schematic diagram of the overall structure of the utility model;

Fig. 2 is a schematic diagram of the connection relationship between the probe, the pressure guiding tube, the pressure collector and the water inlet switch in the present invention;

Fig. 3 is the structural representation of the utility model probe;

Fig. 4 is a structural schematic diagram of the pressure guide tube of the present invention;

Fig. 5 is a schematic structural view of the pressure collection tube of the present invention;

Fig. 6 is a schematic structural diagram of the water inlet switch of the present invention.

Explanation of reference signs:

1. Probe; 2. Pressure guide tube; 21. Outer tube; 22. Inner tube; 23. Hose connector; 3. Pressure collection tube; 31. Measurement port; 4. Differential pressure gauge; 5. Paperless recorder ; 6, data processor; 7, power module; 8, water inlet switch; 9, threaded connection pipe; 10, threaded connection sleeve;

detailed description

The specific embodiments of the present utility model will be described in detail below in conjunction with accompanying drawings 1 to 6 , but it should be understood that the protection scope of the present utility model is not limited by the specific embodiments.

As shown in Figures 1 to 6, a soil moisture characteristic curve measuring instrument provided by the utility model includes a probe 1, a pressure guiding device, a pressure acquisition device, and a differential pressure measuring device. The probe 1 is a clay head of a porous medium, and the guiding The pressure device includes a pressure guide tube 2, the pressure guide tube 2 includes an inner tube 22, the inner tube 22 is a flexible pipe, the inner tube 22 is covered with an outer tube 21, the outer tube 21 is a telescopic hard tube, and the end of the inner tube 22 is connected with A hose connector 23, the convex edge of the hose connector 23 is connected to the end of the outer tube 21, one end of the inner tube 22 is connected to the probe through a connection structure, the pressure acquisition device includes a pressure acquisition tube 3, the pressure acquisition tube 3 is three One end of the pressure collection tube 3 is connected to the end of the pressure guide tube 2 away from the probe 1 through the connection structure, and the other end is connected to the water inlet switch 8. The pressure collection tube 3 is provided with a measurement port 31, and the measurement port is connected to a differential pressure measuring device.

When in use, after the clay head is soaked and saturated by water, a water film is formed inside the clay head until it exchanges with the water in the soil. Change, the pressure change in the pipe will be measured by the differential pressure measuring device in real time, wherein the pressure guiding pipe 2 can use a shower hose, its outer wall is durable, it can be damaged by insects in the field measurement experiment, and it can be naturally coiled, Small footprint, light weight, simple and easy to carry, reducing the manpower consumption of field measurements, and its built-in soft ring also provides great air tightness; natural gas air ducts can also be used, and its material is hard to prevent soil microbial damage , high air tightness, anti-aging and so on.

Further, one end of the probe 1 is provided with a threaded connection tube 9, and the end of the pressure guiding tube pressure collection tube 3 close to the pressure guiding tube 2 is also provided with a threaded connecting tube 9, and the threaded connecting tubes 9 are used to pass through the connecting structure and the pressure guiding tube 2. connect.

Further, the connection structure includes a threaded connection sleeve 10 matched with the threaded connection pipe 9 , one end of the threaded connection sleeve 10 is sleeved on the outer pipe 21 and sealed with the hose connector 23 , and the other end is connected with the corresponding threaded connection pipe 9 connect.

When in use, as shown in Figure 4, first set the two threaded connection sleeves 10 in the middle section of the outer tube 21 in two different opening directions, and then take the right end as an example, press the hose connector 23 into one end of the inner tube 22 nozzle , then install the hose connector 23 successfully connected with the inner tube 22 into the outer tube 21, then place the airtight gasket 11 on the surface of the hose connector 23, and finally pull the threaded sleeve 10 from the middle to the pipe mouth, Embed the airtight gasket 11, the left end and the right end are installed in the same way, secondly, as shown in Figure 3, connect the threaded connecting pipe 9 on the clay head with the threaded connecting sleeve 10 at the left end of the pressure guiding tube 2, and secondly, as shown in Figure 5, connect the pressure The threaded connection pipe 9 at one end of the collection pipe 3 is connected with the threaded connection sleeve 10 at the right end of the pressure guiding pipe 2 .

Further, the differential pressure measurement device includes a differential pressure gauge 4, the measurement end of the differential pressure gauge 4 is connected to the measurement port 31 of the pressure collection tube 3, the differential pressure gauge 4 is connected to a power module 7, and the range of the differential pressure gauge 4 is based on the actual ground conditions. Burial depth selection.

Further, the differential pressure gauge 4 is connected with the paperless recorder 5, and the paperless recorder 5 intelligently collects every second of data, which greatly improves the accuracy of the experimental data and reduces the consumption of manpower and errors in human reading and counting.

Further, the paperless recorder 5 is connected with a data processor 6, and the data processor 6 is a computer.

How to use this example

The utility model provides a soil moisture characteristic curve measuring instrument. When in use, the specific measurement steps are as follows:

① First, use a drill or a Luoyang shovel to drill a hole with a diameter of 10 to 15 cm, and drill to a certain depth according to actual needs;

②Preparation of anaerobic water: Boil a certain amount of tap water and let it cool down;

③ Exhaust: Turn on the water inlet switch 8, tilt the pressure guide tube 2, pour in anaerobic water to the edge of the measurement port 31, and let it stand still to evaporate the water in the clay head. After a period of time, gently shake the instrument to catch the air. Make small bubbles, repeat several times until no bubbles overflow, and then drain the water;

④ Check the air tightness: tighten the water inlet switch 8, place the measuring instrument of the cavity in the water body, and the water body submerges the clay head, and see if the reading of the differential pressure gauge 4 changes;

⑤ Pre-embedded clay head: Put the pressure guiding pipe 2 vertically into the hole, and pour a little mud to make the pressure guiding pipe and the soil tightly combined, and compact the surrounding filling soil.

⑥ Save the experimental data: connect the differential pressure gauge 4 to the paperless recorder 5, and connect the paperless recorder 5 to the computer to collect and process the experimental data.

The utility model connects the pressure guiding tube with the probe. During the process of exchanging the probe with the water in the soil, the volume in the pressure guiding tube changes accordingly, and the real-time measurement of the volume change in the tube through the differential pressure measuring device makes the measurement result more accurate. The pressure guiding tube includes an inner tube and an outer tube. When in use, the length of the pressure guiding tube can be adjusted according to the actual measurement requirements to achieve a large buried depth measurement, and it is possible to insert measuring instruments of different ranges into different sections of a section at the same time, which improves the Measuring efficiency, the utility model adopts the combination of paperless recorder and computer for data collection, realizes automatic data collection, and reduces manpower consumption.

The above disclosures are only preferred specific embodiments of the present utility model, but the embodiments of the present utility model are not limited thereto, and any changes conceivable by those skilled in the art should fall within the protection scope of the present utility model.

Claims (4)

1. A soil moisture characteristic curve measuring instrument is characterized in that, comprising: probe(1); A pressure guiding device, which includes a pressure guiding tube (2), one end of the pressure guiding tube (2) is connected to the probe (1), and the other end is connected to a pressure acquisition device; The pressure guide tube (2) includes an inner tube (22), the inner tube (22) is covered with an outer tube (21), and the two ends of the inner tube (22) are connected with hose connectors (23). The convex edge of the pipe connector (23) is connected to the end of the outer pipe (21), the inner pipe (22) is a flexible pipe, and the outer pipe (21) is a telescopic hard pipe; The pressure acquisition device includes: a pressure acquisition tube (3), one end of which is connected to the end of the pressure guiding tube (2) away from the probe (1), the other end is connected to a water inlet switch (8), and the peripheral surface of the pressure acquisition tube (3) A measuring port (31) is provided; a differential pressure measuring device, the measuring end of which is connected to the measuring port (31); The side of the hose connector (23) away from the inner tube (22) is connected with a threaded connection sleeve (10), and the probe (1) and the pressure acquisition tube (3) are close to one side of the hose connector (23). Both sides are connected with a threaded connecting pipe (9) matching with the threaded connection sleeve (10), and an airtight gasket (11) is arranged in the threaded connection sleeve (10). 2. A soil moisture characteristic curve measuring instrument as claimed in claim 1, characterized in that, the probe (1) is a clay head. 3. a kind of soil moisture characteristic curve measuring instrument as claimed in claim 1, is characterized in that, described differential pressure measuring device comprises differential pressure gauge (4), and the measuring end of described differential pressure gauge (4) is connected with pressure acquisition The measuring port (31) of the tube (3) is connected. 4. A soil moisture characteristic curve measuring instrument as claimed in claim 3, characterized in that the differential pressure gauge (4) is connected with a paperless recorder (5).

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