CN102937643A - Split-type tensionmeter connected through soft pipes and used for measuring soil water potential - Google Patents

Abstract

The invention discloses a tensiometer for measuring soil water potential connected by a hose, which comprises a clay pipe, and a water injection hose and a pressure guiding hose are respectively sealed on the upper ends of the clay pipe, and the pressure guiding hose is connected to The water collecting pipe for storing water and collecting air has a cover on the water collecting pipe, and a vacuum pressure gauge or a digital pressure sensor is installed at the side end of the water collecting pipe. In traditional use, a vacuum pressure gauge is used for measurement, and when collecting digital signals, it is only necessary to replace the vacuum pressure gauge with a digital pressure sensor, and the other parts are not used for any changes. The signal collected in this way is a digital signal. It is more convenient for subsequent storage and processing. Its structure is simple, easy to manufacture, and easy to use. At the same time, it takes into account traditional and conventional use methods, overcomes some disadvantages of traditional tensiometers, and retains its advantages of low price and simple operation, making the measurement results more accurate and more conducive to scientific measurement. .

Description

A split-type tensiometer for measuring soil water potential connected by a hose

technical field

The invention belongs to the technical field of measurement and control, and relates to an agricultural measuring instrument, in particular to a tensiometer connected by a hose for measuring soil water potential.

Background technique

Soil moisture is an important indicator for the study of agricultural drought and crop drought, and is an important parameter for farmland irrigation management, regional hydrological conditions research, and water balance calculation of watersheds. Especially with the increasingly prominent water crisis, the research on water-saving agriculture is highly valued at home and abroad, and the soil moisture content has become a frequently measured item in the research of water-saving agriculture. The research on the measurement method is mainly reflected in how to measure the soil moisture content quickly, accurately and economically, which is of great significance for timely ascertaining the soil moisture status, so as to make scientific decisions or take reasonable measures in time.

Through the analysis of existing soil water potential measuring instruments, it can be seen that although there are many instruments for measuring soil water potential at present, and there are many principles, there are mechanical and digital display, but there are still many problems in use, or the equipment is complicated , the operation is cumbersome, and requires high professional knowledge of the operator. Either the price is expensive, which is not conducive to popularization and field utilization. In addition, the power consumption is large, which is not conducive to energy saving, especially in the wild environment, the power consumption will limit the use time of the equipment. At the same time, some equipment will also produce radioactive substances, which are harmful to human body and soil.

Soil tensiometer is an instrument for measuring soil water potential. It has a simple structure, is easy to manufacture, and is convenient to use, but it also has the following disadvantages:

1. The measurement accuracy is low, and the readings are all performed by mechanical instruments, which is not conducive to the digital collection and storage of data.

2. It needs irregular water injection. Since the soil tensiometer is a plexiglass or plastic hard rod structure, the soil tensiometer will be greatly disturbed during water injection, which will destroy the soil structure and greatly affect the reliability of the measurement results.

3. Since the soil tensiometer is a plexiglass or plastic hard rod structure, if it is installed in the soil as a whole, water will infiltrate along the hard pipe wall, which will easily cause wall effect.

Through the analysis of the advantages and disadvantages of the tensiometer, it can be seen that in order to better use the tensiometer in scientific measurement, the tensiometer must be continuously improved and perfected.

Contents of the invention

In order to overcome the above defects of the soil tensiometer in the above-mentioned prior art, the object of the present invention is to provide a split type tensiometer connected by a hose for measuring soil water potential, which takes into account the simple and easy-to-use features of the traditional tensiometer. It can also carry out digital collection and storage of data.

In order to realize above-mentioned task, the present invention takes following technical solution:

A hose-connected tensiometer for measuring soil water potential, characterized in that it includes a clay pipe, and a water injection hose and a pressure guiding hose are respectively sealed on the upper ends of the clay pipe, and the pressure guiding hose is connected to The water collecting pipe for storing water and collecting air has a cover on the water collecting pipe, and a vacuum pressure gauge or a digital pressure sensor is installed at the side end of the water collecting pipe.

The hose-connected tensiometer for measuring soil water potential of the present invention adopts a separate design for the clay pipe and the measuring part of the traditional soil tensiometer, so that the laying of the clay pipe is more convenient. Its structure is simple, easy to manufacture, and easy to use. At the same time, it takes into account traditional and conventional use methods, overcomes some disadvantages of traditional tensiometers, but retains its advantages of low price and simple operation, and improves its structure to make the measurement results more accurate. Accurate, more conducive to scientific measurement. In traditional use, the vacuum pressure gauge can be used in the field environment without power supply, and can be used as a traditional tensiometer. When collecting digital signals, you only need to replace the vacuum pressure gauge with a digital pressure sensor, and the other parts are not used for any changes, so that the collected signal is a digital signal, which is more convenient for subsequent storage and processing. .

Description of drawings

Fig. 1 is a tensiometer for measuring soil water potential connected by a hose of the present invention, as an installation structure diagram of a traditional use mode.

Fig. 2 is an installation structure diagram of the conventional use mode of the tensiometer for measuring soil water potential connected by a hose of the present invention.

The marks in Figure 1 and Figure 2 respectively indicate: 1. Cover, 2. Water storage and air collection pipe, 3. Water injection pipe, 4. Pressure guiding pipe, 5. Clay pipe, 6. Vacuum pressure gauge, 7. Digital pressure sensor .

FIG. 3 is a schematic diagram of a hardware circuit for storing and displaying digital signals in the present invention.

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Detailed ways

According to the technical solution of the present invention, a hose-connected tensiometer for measuring soil water potential includes a clay pipe 5, and a water injection hose 3 and a pressure guiding hose 4 are respectively sealed on the 5 upper ends of the clay pipe. The pressure hose 4 is connected to the water collection pipe 2 for storing water and collecting air, the water collection pipe 2 has a cover 1, and a vacuum pressure gauge 6 or a digital pressure sensor is installed on the side end of the water collection pipe 2 7. It is suitable for measuring soil water matrix potential.

The following is the traditional and common use of a tensiometer for measuring soil water potential with this hose connection.

Figure 1 is the installation structure diagram of the traditional usage. Connect the clay pipe 5 and the water collection pipe 2 through the pressure guide pipe 4, so that the clay pipe 5 (ie, the measuring head) can be buried in the soil alone to avoid disturbance of the soil during reading or other operations, and at the same time The influence of wall effects is also avoided. The water injection pipe 3 is sealed on the upper end of the clay pipe 5, so that when the clay pipe 5 is refilled with water, it is not necessary to take the clay pipe 5 out of the soil, which is more convenient to use and avoids the movement of the water potential measurement position at the same point. impact on accuracy. When used as a tradition, a vacuum pressure gauge 6 is installed at the side end of the water storage collecting pipe 2, so that it can be used the same as a traditional tensiometer when used in an outdoor environment, without considering factors such as power supply.

In specific production, the water and gas storage device 2 can be made of transparent machine glass, and the change of the water level in the water and gas storage device 2 can be observed, and the pressure guiding hose 4 is required to be able to withstand pressure.

Figure 2 is the installation structure diagram of the conventional use mode. In this case, except that the vacuum pressure gauge 6 is replaced by a digital pressure sensor 7, other structures are the same as in Fig. 1, since the interface design of the vacuum pressure gauge 6 and the digital pressure sensor 7 at the side end of the water collection pipe 2 are the same, It can be installed interchangeably, so that the collected pressure signal can be converted into a digital signal by the hardware circuit for storing and displaying the digital signal in Figure 3, so that the collected data is more conducive to computer storage and reference.

In the case of Fig. 2, although the digital pressure sensor 7 has been installed, the output signal needs to be processed to obtain accurate data. As shown in Figure 3, the digital pressure sensor 7 is connected to the A/D converter through the operational amplifier. The O interface is connected with a keyboard input module, a liquid crystal display module and a data storage module, and the power module is connected with a digital pressure sensor 7, an operational amplifier and a single-chip microcomputer; wherein, the operational amplifier amplifies weak electrical signals, and the liquid crystal display module is used for real-time display The measured soil water potential, the keyboard input module is used to query historical data and set various parameters, and the data storage module is used to store historical data.

Claims (4)

1. the tensiometer of the measurement soil water potential that connects of a flexible pipe, it is characterized in that, comprise vitrified-clay pipe (5), (5) upper end at vitrified-clay pipe is sealed with respectively a water filling flexible pipe (3) and a pilot flexible pipe (4), described pilot flexible pipe (4) connects the water storage discharge (2) that is used for storing water and collects air, lid (1) is arranged on the water storage discharge (2), and the side in water storage discharge (2) is equipped with pressure vacuum gauge (6) or digital pressure sensor (7).

2. the tensiometer of the measurement soil water potential of flexible pipe connection as claimed in claim 1 is characterized in that, described water storage gas extractor (2) adopts organic glass to make.

3. the tensiometer of the measurement soil water potential of flexible pipe connection as claimed in claim 1 is characterized in that, the pressure vacuum gauge (6) of described water storage discharge (2) side is identical with digital pressure sensor (7) interface, interchangeable installation.

4. the tensiometer of the measurement soil water potential that connects of flexible pipe as claimed in claim 1, it is characterized in that, described digital pressure sensor (7) connects A/D converter by operational amplifier, A/D converter is digital signal with analog signal conversion, be input in the single-chip microcomputer by the I/O interface again, single-chip microcomputer also is connected with keyboard load module, LCD MODULE and data memory module by the I/O interface, and power module connects digital pressure sensor (7), operational amplifier and single-chip microcomputer; Wherein, LCD MODULE is used for showing in real time that the soil water potential that records, keyboard load module are used for enquiry of historical data and set various parameters, and data memory module then is used for store historical data.

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