WO2017146251A1

WO2017146251A1 - Moisture amount detection device

Info

Publication number: WO2017146251A1
Application number: PCT/JP2017/007361
Authority: WO
Inventors: 圭博川原; 亮繁田; 直也宮元; 一洋西岡; 悠揮小島; 妥知白浜; 雄太森澤
Original assignee: 国立大学法人東京大学
Priority date: 2016-02-26
Filing date: 2017-02-27
Publication date: 2017-08-31
Also published as: JP6679088B2; JP2017151042A

Abstract

In the present invention, correction wiring lines 52, 54, 56, 58 are made of the same material as and have the same width, length and spacing as electrical wiring lines 42, 44, 46, 48 which are connected to positive-electrode-side electrodes 32a, 34a, 36a, 38a; and the correction wiring lines are disposed in the vicinity of a ground wiring line 50 that is connected to negative-electrode-side electrodes 32b, 34b, 36b, 38b. A moisture amount Qw(n) is derived on the basis of a corrected capacitance C(n) obtained by subtracting a correction capacitance (electrostatic capacitance) Cb(n) detected using the correction wiring lines 52, 54, 56, 58 and the ground wiring line 50, from an electrostatic capacitance Cp(n) detected using the electrical wiring lines 42, 44, 46 and the ground wiring line 50. Due to this configuration, an error resulting from electrostatic capacitances generated by the electrical wiring lines 42, 44, 46, 48 and so on can be reduced, and a more accurate moisture amount can be detected.

Description

Moisture content detector

The present invention relates to a water content detection device, and more particularly to a water content detection device that detects the amount of water inserted into soil or the like.

Conventionally, as this type of moisture amount detection device, a device in which two electrode pairs are vapor-deposited on an insulating sheet and formed into a cylindrical shape has been proposed (for example, see Patent Document 1). The two electrode pairs of the soil moisture meter are arranged so as to overlap each other in the height direction so as to be in the vertical direction, and the soil is measured based on the capacitance of the two electrode pairs. The amount of water in it is detected. And it is said that the moisture content in the soil can be continuously measured with high accuracy by using these two electrode pairs.

JP 2012-132794 A

However, in the above-described moisture amount detection device, since wiring is connected to each of the two electrode pairs, capacitance is generated between the wirings, and the measured moisture amount may be uncertain. In particular, when a plurality of electrode pairs are provided in the height direction, the capacitance due to the wiring to each electrode pair cannot be ignored.

The main object of the water content detection device of the present invention is to detect the water content more appropriately.

The water content detection apparatus of the present invention employs the following means in order to achieve the main object described above.

The moisture content detection device of the present invention is
A water content detection device that detects the amount of water inserted into soil or the like,
A plurality of electrode pairs horizontally arranged at different heights;
A plurality of electrical wiring pairs each connected to the plurality of electrode pairs and wired to the upper end;
A plurality of correction wirings wired to the same length as the plurality of electrical wirings on the one pole side along the plurality of electrical wirings on the one pole side of the plurality of electrical wiring pairs;
Capacitance detecting means for detecting capacitance of the plurality of electrode pairs using the plurality of electrical wiring pairs;
Correction capacitance detecting means for detecting a capacitance between both wirings as a correction capacitance by using one of the plurality of electric wiring pairs or one of the other electric wirings and the plurality of correction wirings; ,
Water content conversion means for converting the corrected capacity obtained by subtracting the correction capacity from the capacitance of the plurality of electrode pairs into a water content;
It is a summary to provide.

In the moisture amount detection device of the present invention, a plurality of electrode pairs are arranged in different horizontal directions at different heights, and an electric wiring pair is wired to each electrode pair, and one electrode side of the plurality of electric wiring pairs A plurality of correction wirings are wired to the same length as the plurality of electrical wirings on the one pole side along the plurality of electrical wirings. The electrostatic capacitance of the plurality of electrode pairs is detected using a plurality of electrical wiring pairs, and the electrical wiring on one pole side or the electrical wiring on the other pole side of the plurality of electrical wiring pairs and the plurality of correction wirings are used. Then, the capacitance between the two wires is detected as a correction capacitance. Then, the corrected capacitance obtained by subtracting the correction capacitance from the capacitances of the plurality of electrode pairs is converted into a moisture content. The corrected capacitance obtained by subtracting the correction capacitance from the capacitance of the plurality of electrode pairs is obtained by subtracting the capacitance generated between the electric wires connected to the plurality of electrode pairs from the capacitance of the plurality of electrode pairs. Therefore, it is possible to reduce an error in the amount of moisture based on the capacitance generated between the electrical wirings. As a result, the amount of water can be detected more appropriately.

In such a moisture content detection device of the present invention, the electrical wiring on the one pole side or the electrical wiring on the other pole side of the plurality of electrical wiring pairs is connected continuously to the one pole side of the plurality of electrode pairs. The correction capacity detecting means may be means for detecting the correction capacity using the ground wiring and the correction wiring. In this way, the number of wirings can be reduced.

In the moisture amount detection device of the present invention, the sheet-like wiring member in which the plurality of electrode pairs, the plurality of electric wiring pairs, and the plurality of correction wirings are formed on a resin sheet, and the sheet-like wiring. A tubular member around which the member is wound and fixed; a storage member that houses the capacitance detection means, the correction capacitance detection means, and the moisture amount conversion means; and is disposed at the upper end of the tubular member; It can also be provided.

Furthermore, in the moisture content detection device of the present invention, it is also possible to include an umbrella part that is attached above the plurality of electrode pairs and functions as an umbrella with respect to the plurality of electrode pairs. If it carries out like this, it can suppress that the water amount of a measuring object is detected by the water droplet by rain etc. flowing along wiring.

In the moisture amount detection device of the present invention, when the moisture amount detected by all the electrode pairs based on the capacitance of the plurality of electrode pairs is less than a predetermined moisture amount, The capacitance detection unit and the correction capacitance detection unit are controlled so that the capacitance and the correction capacitance are detected, and are detected by one of the electrode pairs based on the capacitance of the plurality of electrode pairs. When the water content is equal to or greater than the predetermined water content, the electrostatic capacity detection means and the correction capacity so that the electrostatic capacity and the correction capacity of the plurality of electrode pairs are detected by a second interval shorter than the first interval. Detection interval control means for controlling the detection means, and transmission means for transmitting the converted water content by wireless communication may be provided. Here, the predetermined moisture amount is appropriately determined such as a moisture amount when there is a certain amount of rainfall. As the amount of water detected by the electrode pair, in addition to using the amount of water converted by the water amount conversion means, the correction dose detected by the correction capacity detection means from the capacitance detected by the capacitance detection means. The corrected capacitance obtained by subtraction may be substituted, or the capacitance detected by the capacitance detection means may be substituted. In this way, when there is no rain, the amount of water detected by all electrode pairs is less than the predetermined amount of water. In this case, detection by the capacitance detection means and the correction capacitance detection means is performed at the first interval. When the amount of water detected by one of the electrode pairs exceeds a predetermined amount of water due to a certain amount of rainfall, the detection by the capacitance detection means and the correction capacitance detection means is performed at a second interval shorter than the first interval. Do. As a result, the frequency of detection can be reduced when there is no rain, the frequency of detection can be increased when there is a certain amount of rain, and the power required for detection can be reduced.

In the moisture amount detection apparatus of the present invention, the moisture amount detected by all the electrode pairs based on the capacitance of the plurality of electrode pairs based on the transmission means for transmitting the converted moisture amount by wireless communication is a predetermined moisture. When the amount is less than the amount, the transmission means is controlled to transmit the amount of water at a first interval, and the amount of water detected by any one of the electrode pairs based on the capacitance of the plurality of electrode pairs is the predetermined amount. A transmission interval control unit that controls the transmission unit so that the moisture amount is transmitted at a second interval shorter than the first interval when the moisture amount is equal to or greater than the first interval may be provided. Here, the predetermined moisture amount is appropriately determined such as a moisture amount when there is a certain amount of rainfall. As the moisture amount detected by the electrode pair, in addition to using the moisture amount converted by the moisture amount conversion means, the correction capacitance detected by the correction capacitance detection means from the capacitance detected by the capacitance detection means. The corrected capacitance obtained by subtraction may be substituted, or the capacitance detected by the capacitance detection means may be substituted. In this way, when there is no rain, the amount of water detected by all the electrode pairs is less than the predetermined amount of water. In that case, the amount of water is transmitted at the first interval, and either electrode is caused by a certain amount of rain. When the amount of water detected by the pair is equal to or greater than the predetermined amount of water, the amount of water is transmitted at a second interval shorter than the first interval. As a result, it is possible to reduce the transmission frequency of the moisture amount when there is no rain, to increase the transmission frequency when there is a certain amount of rain, and to reduce the power required for transmission.

It is a block diagram which shows the outline of a structure of the moisture content detection system 10 which has the moisture content detection apparatus 20 as one Example of this invention. It is a block diagram which shows the outline of a structure of the moisture content detection apparatus 20 of an Example. 2 is a configuration diagram showing a planar configuration of an electrode sheet 30. FIG. It is a graph which shows the relationship between the electrostatic capacitance of

electrode pair

32a, 32b, 34a, 34b, 36a, 36b, correction | amendment capacity | capacitance, and a water level. It is a graph which shows the relationship between the electrostatic capacitance after correction | amendment, and a water level. Capacitance meter of capacitance before correction and capacitance after correction of

electrode pair

32a, 32b, 34a, 34b, 36a, 36b when

electrode pair

32a, 32b arranged at the lowermost part has a water depth of 30 cm It is a table | surface which shows the difference | error with the electrostatic capacitance by. 4 is a flowchart illustrating an example of a detection transmission process executed by a control device 60. It is a flowchart which shows an example of the detection transmission process of a modification.

Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of a water content detection system 10 having a water content detection device 20 as one embodiment of the present invention, and FIG. 2 shows the configuration of the water content detection device 20 of the embodiment. It is a block diagram which shows an outline. The water content detection system 10 includes a plurality of water content detection devices 20 inserted and installed in soil, and a plurality of computers 12 connected to the plurality of water content detection devices 20 via a communication network 14 by wireless communication. This is configured as a system in which the computer 12 collects the water content in the soil detected by the water content detection device 20.

The moisture amount detection device 20 according to the embodiment includes a pipe 22 as a tubular member that forms a skeleton of the device, an electrode sheet 30 wound around the pipe 22, a control device 60 connected to the electrode sheet 30, and the vicinity of the control device 60 And an umbrella member 70 attached to the outside.

In the embodiment, the pipe 22 is formed of vinyl chloride so as to have a length of 50 cm, a thickness of 3.5 mm, and a diameter of 32 mm. That is, it is configured using a general PVC pipe.

The planar configuration of the electrode sheet 30 is shown in FIG. In the embodiment, the electrode sheet 30 is a thin film having a thickness of 50 μm made of polyethylene terephthalate, and four pairs of

electrodes

32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b having a thickness of 40 μm, and the positive electrode side. The

electrical wirings

42, 44, 46, 48 connected to the

electrodes

32a, 34a, 36a, 38a, the ground wiring 50 connected to the

negative electrodes

32b, 34b, 36b, 38b, and the ground wiring 50 are arranged. The correction wirings 52, 54, 56, and 58 are formed. The four

electrode pairs

32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b are arranged at an interval of 10 cm in the vertical direction of FIGS. The

positive electrodes

32a, 34a, 36a, 38a and the

negative electrodes

32b, 34b, 36b, 38b all have a height (vertical direction in FIGS. 2 and 3) of 25 mm and a width (in FIGS. 2 and 3). Is formed as a rectangular electrode of 70 mm, and the distance (gap) between the

positive electrode

32a, 34a, 36a, 38a and the

negative electrode

32b, 34b, 36b, 38b is 1 mm. Has been placed. The

electric wirings

42, 44, 46 and 48 are formed to have a width of 1 mm. The correction wirings 52, 54, 56, and 58 are formed to have the same width and the same length as the

electric wirings

42, 44, 46, and 48 and the same interval.

The control device 60 is mainly configured with a microcomputer as the center. As shown in FIG. 2, the control device 60 is based on the capacitance of each

electrode pair

32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b. A control unit 61 that detects the amount of moisture in the device, a transmission device 68 that transmits the detected amount of moisture to the computer 12 via the communication network 14, and a battery 69 that supplies power to each unit. As described in the functional block of FIG. 2, the control unit 61 includes a capacitance detection unit 62 that detects capacitance using the

electrical wirings

42, 44, 46, and 48 and the ground wiring 50, and a correction. A correction capacitance detection unit 63 that detects a correction capacitance (capacitance) using the

wirings

52, 54, 56, 58 and the ground wiring 50, and a correction capacitance detection unit 63 from the capacitance from the capacitance detection unit 62 The capacitance calculation unit 64 that calculates the corrected capacitance (corrected capacitance) by subtracting the correction capacitance from, and the moisture that converts the corrected capacitance calculated by the capacitance calculation unit 64 into a moisture content Based on the amount conversion unit 65 and the amount of water converted by the amount of water conversion unit 65, a time interval (frequency) for detecting the capacitance and the correction capacitance by the capacitance detection unit 62 and the correction capacitance detection unit 63 is set. Detection interval setting unit 66 and moisture content conversion Water content converted by 65 comprises a transmission control unit 67 for controlling a transmission device 68 to be transmitted by the transmitting apparatus 68. These functional blocks are realized by integrating hardware and software. In the electrostatic capacity detection unit 62 and the correction capacity detection unit 63, the electrostatic capacity (correction capacity) is measured based on charging characteristics when DC power is applied, or is measured based on impedance by applying AC power. You can do it.

In the embodiment, the umbrella member 70 is made of plastic as an umbrella-like member having a maximum diameter of 60 mm, and the amount of moisture is detected so that the

uppermost electrode pair

38a, 38b is positioned about 10 cm from the surface of the soil. Although it depends on the strength of the wind when the apparatus 20 is installed, it is normally configured such that raindrops do not directly hit the electrode sheet 30. In the moisture amount detection apparatus 20 of the embodiment, by providing the umbrella member 70, raindrops that directly hit the electrode sheet 30 flow down along the surface, and

electrode pairs

38a, 38b, and the like based on the raindrops that flow down. Therefore, it is possible to suppress the detection of a water content larger than the water content in the original soil.

Next, the performance of the water content detection device 20 of the embodiment configured in this way will be described. The moisture amount detection device 20 of the embodiment is put in a container such as a bucket and held vertically, and the water depth (Water Level), capacitance and correction capacity of the container are detected, and the corrected capacitance and The capacitance detected by a capacitance meter was compared. As the capacitance meter, for example, a plurality of electrodes arranged at equal intervals in the height direction can be used. FIG. 4 shows the capacitance detected using the

electric wirings

42, 44, 46 and the ground wiring 50, the correction capacity detected using the

correction wirings

52, 54, 56 and the ground wiring 50, and the water level. It is a graph which shows a relationship. In the figure, the solid line A indicates the capacitance detected using the electric wiring 42 and the ground wiring 50 connected to the

electrode pair

32a and 32b arranged at the bottom, and the broken line B is arranged second from the bottom. The capacitance detected using the electrical wiring 44 and the ground wiring 50 connected to the electrode pairs 34a and 34b is shown, and the alternate long and short dash line C is connected to the

electrode pair

36a and 36b arranged third from the bottom. The electrostatic capacitance detected using the electrical wiring 46 and the ground wiring 50 which are made is shown. A solid line D indicates a correction capacity detected using the correction wiring 52 and the ground wiring 50, a broken line E indicates a correction capacity detected using the correction wiring 54 and the ground wiring 50, and an alternate long and short dash line F indicates The correction capacitance detected using the correction wiring 56 and the ground wiring 50 is shown. As shown in the figure, the capacitance detected by using the electrical wiring 42 and the ground wiring 50 connected to the

electrode pair

32a, 32b disposed at the lowermost portion with a water level of about 10 cm rapidly increases, and the water level is about 20 cm. The capacitance detected by using the electrical wiring 44 and the ground wiring 50 connected to the

electrode pair

34a, 34b arranged second from the bottom rapidly increases, and the water level is about 30 cm and arranged third from the bottom. The capacitance detected by using the electrical wiring 46 and the ground wiring 50 connected to the electrode pairs 36a and 36b is rapidly increased. The correction capacity increases as the water level rises. The capacitance detected using the

electrical wirings

42, 44, 46 and the ground wiring 50 is the capacitance of the electrode pairs 32a, 32b, 34a, 34b, 36a, 36b, the

electrical wirings

42, 44, 46 and the ground. It can be considered as the sum of the capacitance of the wiring 50. For this reason, the electrostatic capacitances of the electrode pairs 32a, 32b, 34a, 34b, 36a, 36b are calculated from the electrostatic capacitances detected using the

electrical wirings

42, 44, 46 and the ground wiring 50, and the

correction wirings

52, 54, It is necessary to perform correction to reduce the correction capacitance detected using the grounding wire 56 and the ground wiring 50. FIG. 5 shows the relationship between the corrected capacitance and the water level. In the figure, the solid line A0 indicates the corrected capacitance for the

electrode pair

32a, 32b arranged at the bottom, and the broken line B0 indicates the corrected capacitance for the

electrode pair

34a, 34b arranged second from the bottom. The dashed-dotted line C0 indicates the capacitance after correction for the

electrode pair

36a, 36b arranged third from the bottom.

Capacitance meter of capacitance before correction and capacitance after correction with respect to

electrode pair

32a, 32b, 34a, 34b, 36a, 36b when

electrode pair

32a, 32b arranged at the lowermost part has a water depth of 30 cm The error from the capacitance due to is shown in FIG. In the

electrode pair

32a and 32b arranged at the bottom, the error before correction is 56.0%, but the error after correction is 33.6%. In the

electrode pair

34a and 34b arranged second from the bottom, an error of 22.2% before correction is 5.9% after correction. In the

electrode pair

36a, 36b arranged third from the bottom, an error of 9.7% before correction is 0.2% after correction. From this result, it can be seen that, at any depth of water, the error of the capacitance after the correction is smaller than that before the correction by the capacitance meter. Accordingly, the correction capacitance (static capacitance) detected using the

correction wirings

52, 54, 56, 58 and the ground wiring 50 from the electrostatic capacitance detected using the

electric wirings

42, 44, 46, 48 and the ground wiring 50. By reducing (capacitance), the error from the capacitance detected by the capacitance meter can be reduced. The results in FIG. 6 also show that the error between the corrected capacitance and the capacitance measured by the capacitance meter increases as the water depth increases.

Next, processing of the control device 60 of the moisture amount detection device 20 of the embodiment will be described. FIG. 7 is a flowchart illustrating an example of the detection transmission process executed by the control device 60. This process is repeatedly executed every predetermined time (for example, every minute). When the detection transmission process is executed, the control device 60 first determines whether or not the counter C is greater than or equal to the threshold value Cref (step S100). Here, the counter C is used to set a time interval (frequency) for detecting the amount of water by each of the electrode pairs 32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b. It is counted up or cleared by processing.

When the counter C is less than the threshold value Cref, the moisture amount Qw (n) is compared with the threshold value Qref (step S160). When all the moisture amounts Qw (n) are less than the threshold value Qref, the counter C is increased by the value C1. (Step S170) When any one of the moisture amounts Qw (n) is equal to or greater than the threshold value Qref, the counter C is increased by a value C2 larger than the value C1 (Step S180), and the present detection transmission process is terminated. The moisture amount Qw (n) is the moisture amount detected by the electrode pairs 32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b by the present detection transmission process, and “n” is the

electrode pair

32a, 32b, 1, 2, 3, and 4 correspond to the

electrode pair

34a, 34b, the

electrode pair

36a, 36b, and the

electrode pair

38a, 38b. The threshold value Qref is determined in advance as a value with which it is possible to determine that the amount of water has increased due to rainfall. Accordingly, the processing in steps S160 to S180 is performed by counting the counter C by a small value C1 when no rain is detected based on the moisture amount detected by the electrode pairs 32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b. When the rain is detected, the counter C is incremented by a large value C2. Therefore, when rain is not detected, step S100 is affirmed at a long time interval, and when rain is detected, step S100 is affirmed at a short time interval. That is, when no rain is detected, the moisture amount Qw (n) detection process and the transmission process in steps S110 to S150 are performed at a long time interval, and when rain is detected, the moisture content in steps S110 to S150 is detected at a short time interval. The detection process and the transmission process of the quantity Qw (n) are performed. As described above, the interval between the detection process and the transmission process of the moisture amount Qw (n) is set to a long time interval when no rain is detected, and a short time interval when the rain is detected when the rain is not detected. This is based on the fact that the time variation of the water content Qw (n) is small while the time variation of the water content Qw (n) is large during the rain. The threshold value Cref and the values C1 and C2 are the detection transmission process start interval, the time interval for executing the detection process and transmission process of the moisture amount Qw (n) when no rain is detected, and the moisture when the rain is detected. It can be set as appropriate based on the time interval for executing the detection process and the transmission process of the quantity Qw (n).

When the counter C is equal to or larger than the threshold Cref, the counter C is cleared to 0 (step S110), and the electrostatic capacitance Cp (n) is detected using the

electrical wirings

42, 44, 46, 48 and the ground wiring 50. The correction capacitance Cb (n) is detected using the

correction wirings

52, 54, 56, 58 and the ground wiring 50 (step S120). The capacitance can be measured based on charging characteristics when DC power is applied, or can be measured based on impedance by applying AC power. Subsequently, the corrected capacity C (n) is calculated by subtracting the corrected capacity Cb (n) from the capacitance Cp (n) (step S130), and the moisture content Qw (n) is calculated from the corrected capacity C (n). Derived (step S140). Here, as a method of deriving the water content Qw (n) from the corrected capacity C (n), the relationship between the corrected capacity and the water content is obtained in advance by experiments or the like and stored as a map, and the corrected capacity is obtained. Can be cited as a method for deriving a corresponding amount of water from a map. Then, the derived moisture amount Qw (n) is transmitted (step S150), the processes of steps S160 to S180 are executed, and the present detection transmission process is terminated.

In the moisture content detection device 20 of the embodiment described above, the

electrical wirings

42, 44, 46, 48 connected to the

positive electrodes

32a, 34a, 36a, 38a have the same width and the same length by the same material. Correction wirings 52, 54, 56, and 58 having the same interval are disposed in the vicinity of the ground wiring 50 connected to the

negative electrodes

32b, 34b, 36b, and 38b. Then, the correction capacitance detected using the

correction wirings

52, 54, 56, 58 and the ground wiring 50 from the electrostatic capacitance Cp (n) detected using the

electric wirings

42, 44, 46 and the ground wiring 50. A moisture amount Qw (n) is derived based on the corrected capacity C (n) obtained by subtracting Cb (n). Thereby, the error based on the electrostatic capacitance caused by the

electrical wirings

42, 44, 46, 48, etc. can be reduced, and a more appropriate moisture amount can be detected.

In addition, in the moisture amount detection device 20 of the embodiment, by providing the umbrella member 70, raindrops that directly hit the electrode sheet 30 flow down along the surface, and the electrode pairs 38a and 38b are based on the raindrops that have flowed down. Thus, it is possible to suppress the detection of a water content larger than the water content in the original soil. As a result, a more appropriate amount of water can be detected.

Further, in the moisture amount detection device 20 of the embodiment, the execution interval of the moisture amount Qw (n) detection process and transmission process is set to a long time interval when no rain is detected, and to a short time interval when rain is detected. Thus, the time interval can be set as required, and power consumption can be suppressed. As a result, in the case where the batteries 69 having the same capacity are used, the moisture amount Qw (n) can be detected over a longer period of time than when the detection interval of the moisture amount Qw (n) and the execution interval of the transmission process are not changed. The process and the transmission process can be executed, and when the detection process and the transmission process of the moisture amount Qw (n) over the same time are executed, the detection process and the transmission process of the moisture amount Qw (n) are executed. A battery 69 having a small capacity, that is, a small battery 69 can be obtained as compared with a battery whose distance is not changed.

In the moisture amount detection device 20 of the embodiment, four

electrode pairs

32a, 32b, 34a, 34b, 36a, 36b, 38a, and 38b are arranged at intervals of 10 cm. However, the distance between the electrode pairs is limited to 10 cm. It is not a thing, and it may be 5 cm intervals, 15 cm intervals, 20 cm intervals, or any interval. Further, the number of electrode pairs is not limited to four, but may be three or less, or five or more. Further, the size of the electrode pair is not limited to 25 mm × 70 mm.

In the moisture amount detection apparatus 20 of the embodiment, the

correction wirings

52, 54, 56, 58 formed to have the same width, the same length, and the same interval as the

electric wirings

42, 44, 46, 48 are ground wirings. The correction wirings 52, 54, 56, and 58 may be disposed in the vicinity of the

electric wirings

42, 44, 46, and 48.

In the moisture amount detection device 20 of the embodiment, the ground wiring 50 connected to the

negative electrodes

32b, 34b, 36b, and 38b is provided. However, each of the

negative electrodes

32b, 34b, 36b, and 38b has a negative electrode. It is good also as a thing provided with the electric wiring of the side.

In the water content detection apparatus 20 of the embodiment, the execution interval of the detection process and the transmission process of the water content Qw (n) is lengthened or shortened depending on whether or not all the water content Qw (n) is less than the threshold value Qref. However, instead of the moisture amount Qw (n), the moisture depends on whether or not all of the capacitance Cp (n) detected using the

electrical wirings

42, 44, 46 and the ground wiring 50 is less than the threshold value. The execution interval between the detection process and the transmission process of the amount Qw (n) may be lengthened or shortened, or the corrected capacity C obtained by subtracting the correction capacity Cb (n) from the capacitance Cp (n). Depending on whether or not all of (n) are less than the threshold, the execution interval between the detection process of the moisture amount Qw (n) and the transmission process may be lengthened or shortened.

In the moisture amount detection device 20 of the embodiment, the execution interval between the detection process and the transmission process of the moisture amount Qw (n) is set to a long time interval when no rain is detected, and is set to a short time interval when rain is detected. Only the processing execution interval may be a long time interval when no rain is detected, and may be a short time interval when rain is detected. In this case, the detection transmission process illustrated in FIG. 8 may be executed. In the detection transmission process of FIG. 8, first, the capacitance Cp (n) is detected using the

electrical wirings

42, 44, 46, 48 and the ground wiring 50, and the

correction wirings

52, 54, 56, 58 and the ground wiring are detected. 50, the correction capacity Cb (n) is detected (step S200). Then, the corrected capacitance Cb (n) is subtracted from the capacitance Cp (n) to calculate the corrected capacitance C (n) (step S210), and the moisture content Qw (n) is derived from the corrected capacitance C (n). (Step S220). The processing in steps S200 to S220 so far is the same as the processing in steps S120 to S140 of the detection transmission processing in FIG. Subsequently, the moisture amount Qw (n) is compared with the threshold value Qref (step S230). When all the moisture amounts Qw (n) are less than the threshold value Qref, the counter C is increased by the value C1 (step S240). When any one of the quantities Qw (n) is equal to or larger than the threshold value Qref, the counter C is incremented by a value C2 larger than the value C1 (step S250). Then, the counter C is compared with the threshold value Cref (step S260). When the counter C is less than the threshold value Cref, the main detection transmission process is terminated. When the counter C is equal to or larger than the threshold value Cref, the moisture amount Qw (n) is transmitted. (Step S270), the counter C is cleared to 0 (step S280), and this detection transmission process is terminated. As described above, even if only the transmission processing execution interval is set to a long time interval when rain is not detected and is set to a short time interval when rain is detected, the effect of suppressing power consumption and a longer time can be achieved. The effect that the detection process and the transmission process of the moisture amount Qw (n) over the range can be executed, the effect of downsizing the battery 69, and the like can be achieved.

As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

The present invention can be used in the manufacturing industry of water content detection devices.

Claims

A water content detection device that detects the amount of water inserted into soil or the like,
A plurality of electrode pairs horizontally arranged at different heights;
A plurality of electrical wiring pairs each connected to the plurality of electrode pairs and wired to the upper end;
A plurality of correction wirings wired to the same length as the plurality of electrical wirings on the one pole side along the plurality of electrical wirings on the one pole side of the plurality of electrical wiring pairs;
Capacitance detecting means for detecting capacitance of the plurality of electrode pairs using the plurality of electrical wiring pairs;
Correction capacitance detecting means for detecting a capacitance between both wirings as a correction capacitance by using one of the plurality of electric wiring pairs or one of the other electric wirings and the plurality of correction wirings; ,
Water content conversion means for converting the corrected capacity obtained by subtracting the correction capacity from the capacitance of the plurality of electrode pairs into a water content;
A water content detection device comprising:
The water content detection device according to claim 1,
The electrical wiring on one pole side or the electrical wiring on the other pole side of the plurality of electrical wiring pairs is a ground wiring continuously connected to the one pole side of the plurality of electrode pairs,
The correction capacity detection means is means for detecting the correction capacity using the ground wiring and the correction wiring.
Moisture content detector.
The water content detection device according to claim 1 or 2,
A sheet-like wiring member in which the plurality of electrode pairs, the plurality of electric wiring pairs, and the plurality of correction wirings are formed on a resin sheet;
A tubular member around which the sheet-like wiring member is wound and fixed;
A storage member that stores the capacitance detection means, the correction capacitance detection means, and the moisture amount conversion means, and is disposed at an upper end portion of the tubular member;
A water content detection device comprising:
The water content detection device according to any one of claims 1 to 3,
An umbrella part that is attached above the plurality of electrode pairs and functions as an umbrella for the plurality of electrode pairs;
A water content detection device comprising:
The water content detection device according to any one of claims 1 to 4,
When the amount of water detected by all electrode pairs is less than a predetermined amount of water based on the capacitance of the plurality of electrode pairs, the capacitance of the plurality of electrode pairs and the correction capacitance are detected by the first interval. The capacitance detection unit and the correction capacitance detection unit are controlled so that the amount of moisture detected by any one of the electrode pairs based on the capacitance of the plurality of electrode pairs is equal to or greater than the predetermined moisture amount. Sometimes, the detection interval control for controlling the capacitance detection means and the correction capacitance detection means so that the capacitance and the correction capacitance of the plurality of electrode pairs are detected at a second interval shorter than the first interval. Means,
Transmitting means for transmitting the converted moisture content by wireless communication;
A water content detection device comprising:
The water content detection device according to any one of claims 1 to 4,
Transmitting means for transmitting the converted moisture content by wireless communication;
When the moisture amount detected by all electrode pairs based on the capacitances of the plurality of electrode pairs is less than a predetermined moisture amount, the transmission means is controlled to transmit the moisture amount at a first interval, When the water amount detected by any one of the electrode pairs based on the capacitance of the plurality of electrode pairs is equal to or greater than the predetermined water amount, the water amount is transmitted at a second interval shorter than the first interval. Transmission interval control means for controlling the transmission means;
A water content detection device comprising: