JP4189864B2 - Method and apparatus for measuring moisture content in medium - Google Patents

Description

The present invention relates to a water content measuring method and apparatus for measuring the water content in the medium such as soil.

  Conventionally, a parallel two-wire transmission line configured such that the first and second linear conductors extend vertically opposite to each other and the upper free end thereof is used as a signal input / output end is measured for moisture content. The first and second linear conductors are arranged in the medium to be extended in the vertical direction, and in this state, a pulse wave is supplied to the signal input / output end of the parallel two-wire transmission line, and the pulse wave is parallel The two-wire transmission path is propagated toward the lower end thereof, whereby the pulse wave propagating to the parallel two-wire transmission path is reflected at the lower end of the parallel two-line transmission path, and the reflected pulse wave is transmitted to the parallel two-wire transmission path. Propagating toward the signal input / output end, receiving the reflected pulse wave at the signal input / output end, and at the time of supplying the pulse wave to the signal input / output end of the parallel two-wire transmission line at that time Time until the reflected pulse wave is received at the same signal input / output end of the parallel 2-wire transmission line Then, the pulse wave propagation time is measured, and then the pulse wave propagation time is determined by the average dielectric constant in the region where the parallel two-wire transmission line of the medium is arranged as an element. By calculating using the wave propagation time, an average dielectric constant is obtained in the region where the parallel two-wire transmission line of the medium is arranged, and in the region where the parallel two-wire transmission line of the medium is arranged. Since the average dielectric constant is determined by the average amount of water per unit volume (unit volume) in the area where the parallel two-wire transmission line is arranged in the medium, the calculation using that dielectric constant To obtain an average amount of water per unit volume (unit volume) or in a predetermined volume (planned volume) or total volume (total volume) in a region in the medium where the parallel two-wire transmission line is arranged. A method for measuring the amount of water in a medium is proposed. That.

  According to the above-described conventional method for measuring the amount of water in a medium, the region where the parallel two-wire transmission line of the medium is arranged is substantially free of substances having a relatively high conductivity such as salinity. If it is not included in a large amount, even if the pulse wave propagating from the signal input / output end to the lower end is hardly absorbed or absorbed at the lower end of the parallel two-wire transmission path Therefore, the reflected pulse wave cannot be obtained at the lower end of the parallel two-wire transmission path, and therefore moisture in the region where the parallel two-wire transmission path is arranged in the medium is not obtained. The amount can be measured, but if the area where the parallel two-wire transmission line of the medium is arranged contains a large amount of a material exhibiting relatively high conductivity such as salinity, a signal is sent to the parallel two-wire transmission line. Pal propagating from the input / output end to the lower end Waves are almost absorbed at the lower end of the parallel two-line transmission path, and a reflected pulse wave is substantially not obtained at the lower end of the parallel two-line transmission path, so that in the region where the parallel two-line transmission path in the medium is arranged There was a fear that the moisture content could not be measured.

Therefore, the present invention proposes a novel method and apparatus for measuring the amount of water in a medium that does not have the risk of the conventional method for measuring the amount of water in a medium.

The method and apparatus for measuring the amount of moisture in a medium according to the present invention generally supplies a frequency signal to the signal input end of a parallel two-wire transmission line, transmits the frequency signal to the parallel two-wire transmission line, and performs the parallel two-line transmission. The frequency signal transmitted to the path is obtained from the signal output end of the parallel two-wire transmission path, and at that time, the frequency signal supplied to the signal input end of the parallel two-line transmission path and the signal of the parallel two-line transmission path If attention is paid to the frequency signal transmitted to the parallel two-wire transmission line obtained at the output end, a phase difference is generated between them, and the phase difference of the medium between the two lines of the parallel two-wire transmission line is generated. The average dielectric constant is determined as an element, while the dielectric constant is determined based on the average amount of moisture per unit volume (unit volume) in the medium between the two lines of the parallel two-wire transmission line. Dielectric constant and the type of medium between two lines of a parallel two-wire transmission line, parallel It is determined by the sum of the average dielectric constant determined by the salinity contained in the medium between the two lines of the line transmission line as an element. From this, the distance between the two lines of the parallel two-line transmission line just described If the dielectric constant determined with the average amount of moisture per unit volume (unit volume) in the medium as an element is obtained, the unit volume (unit) in the medium between the parallel two-wire transmission lines is calculated using the dielectric constant. Based on what the inventor recalled that the average amount of water per volume) or the planned volume (scheduled volume) or total volume (total volume) can be determined. It has the structure described in the following.

  The method for measuring the amount of moisture in a medium according to the present invention includes (a) a folded parallel two-wire transmission line having a signal input end and a signal output end in the medium whose moisture amount is to be measured, and (b) the above An i-th frequency signal Si having an i-th (i = 1, 2,... N, where n is an integer of 2 or more) frequency fi is supplied to the signal input end of the folded parallel two-wire transmission line, and (c ) The frequency signal Si supplied to the signal input end of the folded parallel two-wire transmission line, and the signal input end of the folded parallel two-wire transmission line obtained from the signal output end of the folded parallel two-wire transmission line And i-th phase difference display information Di representing the phase difference θi between them is generated using the i-th frequency signal Si ′ based on the frequency signal Si, and (d) the i-th phase difference display Using the information Di, the folded parallel two-wire transmission line of the medium I-th dielectric constant display information Ei representing an average dielectric constant εi in the arranged region is generated, and (e) the i-th frequency signal to the signal input terminal of the folded parallel two-wire transmission line By performing a series of processes of supplying Si, generating the i-th phase difference display information Di, and generating the i-th dielectric constant display information Ei, with i being 1, 2,. Using the plurality of n first, second... Nth dielectric constant display information E1, E2... En, in the region where the folded parallel two-line transmission path of the medium is arranged, Generating dielectric constant display information E0 representing an average dielectric constant ε0 which has substantially no frequency dependency or little frequency dependency, and (f) generates the dielectric constant display information E0. Using the folded parallel two-wire transmission line in the medium. Generating a moisture content display information representing the average water content in the region.

  The apparatus for measuring moisture content in a medium according to the present invention comprises: (a) a folded parallel two-wire transmission line having a signal input end and a signal output end, disposed in a medium whose moisture content is to be measured; b) A plurality of first, second,..., having first, second... n (where n is an integer equal to or greater than 2) frequencies supplied to the signal input end of the folded parallel two-wire transmission line. Frequency signal generating means for generating n-th frequency signals S1, S2... Sn, and (c) the i-th (i = 1, 2,... N) supplied to the signal input terminal of the folded parallel two-wire transmission line. ) And the i-th frequency signal Si supplied to the signal input terminal of the folded parallel two-line transmission line is obtained from the signal output terminal of the folded parallel two-line transmission line. The frequency difference Sii is used to express the phase difference θi between them. Phase difference display information generating means for generating i-th phase difference display information Di, and (d) an area where the folded parallel two-wire transmission line of the medium is arranged using the i-th phase difference display information A dielectric constant display information generating means for generating the i th dielectric constant display information Ei representing the average dielectric constant εi at (i), and (e) the i th input to the signal input terminal of the folded parallel two-wire transmission line. A series of processes of supplying the frequency signal Si, generating the i-th phase difference display information Di, and generating the i-th dielectric constant display information Ei is generated with i being 1, 2,. Frequency in a region where the folded parallel two-line transmission line of the medium is arranged using a plurality of n first, second... Nth dielectric constant display information E1, E2. Has little or no frequency dependence, if any A dielectric constant display information generating means for generating dielectric constant display information E0 representing an average dielectric constant ε0; and (f) the folded parallel two-line transmission in the medium using the dielectric constant display information E0. Water content display information generating means for generating water content display information representing an average water content in the area where the path is arranged.

As the folded two parallel wire transmission line used for the water content measuring method and apparatus in the medium according to the present invention, them between the first and second linear portions and the free end of one of the them to (a) opposite And a U-shaped conductor having a folded portion extending integrally with the U-shaped conductor, and a linear conductor extending in parallel with and between the first and second linear portions of the U-shaped conductor. (B) The first parallel portion of the U-shaped conductor has a free end opposite to the folded portion side and a free end of the straight conductor, and the folded parallel two-wire transmission line (C) the folded parallel 2 with the free end of the second linear portion of the U-shaped conductor opposite to the folded portion side and the free end of the linear conductor. The signal output terminal of the line transmission path may be used .

  According to the method for measuring the amount of moisture in a medium according to the present invention, or a predetermined volume (planned volume) or total volume (total volume) per unit volume (unit volume) in the region where the folded parallel two-wire transmission line is arranged in the medium. Average volume of water is easily and accurately measured assuming that it is not affected by factors such as the type of medium and salinity in the area where the folded parallel two-wire transmission line is located in the medium. can do.

  According to the apparatus for measuring the amount of water in a medium according to the present invention, the apparatus for measuring the amount of moisture in a medium or a predetermined volume (scheduled volume) per unit volume (unit volume) in the region where the folded parallel two-wire transmission path is arranged in the medium is used. Alternatively, the average water content of the total volume (total volume) can be easily determined as not affected by factors such as the type of medium, salinity in the area where the folded parallel two-wire transmission path is arranged in the medium. And it can measure with high precision.

If the folded parallel two-wire transmission line having the configuration described in paragraph [0008] is used in the method and apparatus for measuring the amount of moisture in the medium according to the present invention, the medium is used in the method and apparatus for measuring the amount of moisture in the medium according to the present invention. Average moisture content per unit volume (unit volume) or planned volume (planned volume) or total volume (total volume) in the area where the folded parallel two-wire transmission line is arranged is the type of medium, medium It can be measured easily and with high accuracy, assuming that it is not affected by factors such as salinity in the region where the folded parallel two-wire transmission line is arranged.

  Next, referring to FIGS. 1 to 3, the first embodiment of the method for measuring the amount of moisture in the medium according to the present invention, the first embodiment of the apparatus for measuring the amount of moisture in the medium according to the present invention, and the present invention. A description will be given together with an example of a folded parallel two-wire transmission line used in the method and apparatus for measuring the amount of moisture in the medium.

  First, an embodiment of a folded parallel two-wire transmission line used in the first embodiment of the method for measuring the amount of moisture in the medium according to the present invention will be described. In FIG. And (a) the first and second linear portions 11a and 11b facing each other and the folded portion 12 extending integrally therewith between the free ends of the first and second linear portions 11a and 11b. 14 and a U-shaped conductor 13 suspended substantially by the same length as the first and second linear portions 11a and 11b of the U-shaped conductor 13 and insulated in parallel with them. And a linear conductor 15 that is suspended and extended from the conductive support substrate 14.

  In this case, the U-shaped conductor 13 passes through the insulating support substrate 14 from the lower side of the linear portions 11a and 11b opposite to the folded portion 12 side from below, for example, in advance to the free ends. The fixing means (not shown) using the attached screw and a nut screwed thereto is fixed to be suspended from the insulating support substrate 14, and the linear conductor 15 is also the same insulating support substrate 14. Further, one free end of the insulating support substrate 14 is suspended from the insulating support substrate 14 by passing through the insulating support substrate 14 from below and being fixed by the same fixing means (not shown).

  Further, the linear portions 11a and 11b, the folded portion 12, and the linear conductor 15 of the U-shaped conductor 13 have substantially the same cross-sectional shape (for example, a circular cross-section and an annular cross-section) and have substantially the same cross-sectional outer dimensions. However, the inner distance between each of the linear portions 11a and 11b of the U-shaped conductor 13 and the linear conductor 15 is equal to each other, and each of the folded portions of the U-shaped conductor 13 is linear with each other. The inner distance between the conductor 15 and the free end opposite to the insulating support substrate 14 is substantially equal to the inner distance between each of the linear portions 11 a and 11 b of the U-shaped conductor 13 and the linear conductor 15.

  Further, the first linear portion 11a of the U-shaped conductor 13 has a free end on the insulating support substrate 14 side and a free end of the linear conductor 15 on the insulating support substrate 14 side. The signal input end 16 of the line transmission path 10 is used, and the signal output of the folded parallel two-line transmission path 10 is provided with the free ends of the second linear portion 11b and the linear conductor 15 on the insulating support substrate 14 side. A folded parallel two-wire transmission path is formed between the signal input terminal 16 and the signal output terminal 17.

  Thus, the configuration of the embodiment of the folded parallel two-wire transmission line 10 used in the first embodiment of the method and apparatus for measuring the amount of water in the medium according to the present invention has been clarified.

  In the first embodiment of the method for measuring the amount of moisture in the medium according to the present invention, as shown in FIG. 1, the folded parallel two-wire transmission line 10 having the configuration described above with reference to FIG. It arrange | positions so that the signal input end 16 and the signal output end 17 may face slightly on the surface of the medium 20 in the medium 20 such as soil to be projected.

  Then, a processor 32 connected to the bus 31, a ROM-type read-only program storage unit 33, a RAM-type read / write storage unit 34, a data input / output unit 35, a control voltage output unit 36, an AD conversion unit 37, etc. The computer apparatus 30 having a publicly known per se computer is used to output the first control voltage V1 obtained by the control voltage output unit 36 from the computer apparatus 30 and the variable frequency signal known per se by the first control voltage V1. The generation circuit 40 is controlled to output a first frequency signal S1 composed of a sine wave or a cosine wave having a first frequency f1 (for example, 30 MHz) from the variable frequency signal generation circuit 40, and the first frequency signal S1 is supplied to the signal input end 16 of the folded parallel two-wire transmission line 10 disposed in the medium 20, and the first frequency signal S1 It is transmitted to the folded two parallel wire transmission path 10, from the signal output terminal 17 of the folded two parallel wire transmission path 10, so as to obtain a first frequency signal S1 'based on the first frequency signal S1.

  Further, the first frequency signal S1 supplied to the signal input end 16 of the folded parallel two-wire transmission line 10 is converted into a known phase difference having two signal input ends 41a and 41b and one signal output end 41c. The first frequency signal S 1 ′ supplied directly to one signal input terminal 41 a of the detection circuit 41 and obtained at the signal output terminal 17 of the folded parallel two-wire transmission line 10 is passed through the automatic gain control circuit 42. This is supplied to the other signal input terminal 41b of the phase difference detection circuit 41, and represents the phase difference θ1 between the first frequency signal S1 and the first frequency signal S1 ′ from the signal output terminal 41c of the phase difference detection circuit 41. The first phase difference display information D1 is obtained.

  In this case, the first frequency signal S1 supplied to the signal input end 16 of the folded parallel two-wire transmission line 10 is known per se having two signal input ends 43a and 43b and two signal output ends 43c and 43d. The signal level detection circuit 43 is supplied directly to one signal input terminal 43a, and the first signal level display indicating the level of the first frequency signal S1 from the signal output terminal 43c of the signal level detection circuit 43. The first frequency signal S1 ′ obtained from the information F1 and obtained at the signal output terminal 17 of the folded parallel two-line transmission line 10 is supplied to the other signal input terminal 43b of the signal level detection circuit 43, and its signal level First signal level display information F1 ′ representing the level of the first frequency signal S1 ′ is obtained from the signal output terminal 43d of the detection circuit 43, and the first signal level display information F1 and F1 are obtained. Are supplied to signal input terminals 44a and 44b of a difference output circuit 44 known per se having two signal input terminals 44a and 44b and one signal output terminal 44c, respectively. From the signal level display information F1 and F1 ′, the first difference output G1 having the signal level represented by the signal level display information F1 and F1 ′ is obtained, the above-described automatic gain control circuit 42 is controlled by the first difference output G1, and the phase difference detection circuit The first frequency signal S 1 ′ supplied to the signal input terminal 41 b to 41 has the same signal level as the first frequency signal S 1 supplied to the signal input terminal 41 a of the phase difference detection circuit 41. Yes.

  Further, the first phase difference display information D1 obtained from the signal output terminal 41c of the phase difference detection circuit 41 as described above is supplied to the computer device 30. In the computer device 30, the AD conversion unit 37 The digitized first phase difference display information D1 ′ of the first phase difference display information D1 is generated.

  Then, (a) the phase difference display information D1 ′ generated in the computer device 30 is supplied to the signal input terminal 16 of the folded parallel two-line transmission path 10 and the folded parallel two-line transmission path 10 Represents the phase difference θ1 with respect to the first frequency signal S1 ′ obtained from the signal output terminal 17 of the first and second elements, and the phase difference θ1 is independent of the medium 20 such as the length of the folded parallel two-wire transmission line 10 and the magnetic permeability. And the element depending on the medium 20 having an average dielectric constant ε1 in the region where the folded parallel two-line transmission path 10 of the medium 20 is arranged. Elements that do not depend on the medium 20 such as magnetic permeability are elements that are known or are known in advance. For this reason, the average of the medium 20 in the region where the folded parallel two-line transmission line 10 is disposed. Dielectric constant ε Can be obtained by calculation using the phase difference θ1, (b) using the phase difference display information D1 ′ generated now and using the phase difference θ1 represented by the phase difference display information D1 ′. The first dielectric constant display information E1 representing the dielectric constant ε1 in the region where the folded parallel two-line transmission line 10 of the medium 20 is arranged is obtained by the calculation in the processor 32, and the first dielectric constant display is performed. The information E1 is stored in the storage unit 34.

  Next, as described above, the first dielectric constant display information E1 representing the dielectric constant ε1 of the medium 20 is obtained and stored in accordance with the control voltage from the computer device 30. The second control voltage V2 obtained by the output unit 36 is output, the variable frequency signal generation circuit 40 described above is controlled by the second control voltage V2, and the second frequency f2 is output from the variable frequency signal generation circuit 40. The second frequency signal S2 having (for example, 40 MHz) is output, and the second frequency signal S2 is supplied to the signal input terminal 16 of the folded parallel two-wire transmission line 10 disposed in the medium 20, and the second frequency signal S2 is supplied. 2 frequency signal S2 is transmitted to the folded parallel two-wire transmission line 10, and the second frequency signal based on the second frequency signal S2 is transmitted from the signal output terminal 17 of the folded parallel two-wire transmission line 10. S2 ′ is obtained, and the second frequency signal S2 supplied to the signal input terminal 16 of the folded parallel two-line transmission line 10 is directly applied to one signal input terminal 41a of the phase difference detection circuit 41 described above. The second frequency signal S2 ′ supplied and obtained at the signal output end 17 of the folded parallel two-wire transmission line 10 is input to the other signal of the phase difference detection circuit 41 described above via the automatic gain control circuit 42 described above. The second phase difference display information D2 representing the phase difference θ2 between the second frequency signal S2 and the second frequency signal S2 ′ is supplied to the end 41b and from the signal output end 41c of the phase difference detection circuit 41. In addition, the second phase difference display information D2 is supplied to the computer device 30. In the computer device 30, the AD converter 37 performs the digitization of the second phase difference display information D2. Second phase difference display information D2 ′ is generated, and calculation is performed by the processor 32 using the phase difference θ2 between the second frequency signals S2 and S2 ′ represented by the phase difference display information D2 ′. The second dielectric constant display information E2 representing the dielectric constant ε2 in the region where the folded parallel two-line transmission line 10 of the medium 20 is arranged is obtained, and the second dielectric constant display information E2 is stored in the storage unit. 34 is stored.

  In this case as well, the second frequency signal S2 supplied to the signal input terminal 16 of the folded parallel two-wire transmission line 10 is obtained in accordance with the control of the automatic gain control circuit 42 by the first difference output G1. Second signal level display information which is supplied directly to one signal input terminal 43a of the signal level detection circuit 43 and represents the level of the second frequency signal S2 from the signal output terminal 43c of the signal level detection circuit 43. F2 is obtained, and the second frequency signal S2 'obtained at the signal output terminal 17 of the folded parallel two-wire transmission line 10 is supplied to the other signal input terminal 43b of the signal level detection circuit 43 to detect the signal level. The second signal level display information F2 ′ indicating the level of the second frequency signal S2 ′ is obtained from the signal output terminal 43d of the circuit 43, and the second signal level display information F2 and F2 ′ are obtained from the difference output circuit 44. of Signal input terminals 44a and 44b, respectively, and second difference outputs G2 having signal levels indicated by signal level display information F2 and F2 'are obtained from signal output terminals 44c of the difference output circuit 44, respectively. The difference output G2 controls the automatic gain control circuit 42 described above, and the second frequency signal S2 ′ supplied to the signal input terminal 41b to the phase difference detection circuit 41 is the signal input terminal 41a of the phase difference detection circuit 41. It is possible to have the same signal level as that of the second frequency signal S2 supplied to.

Next, the computer device 30 reads the first and second dielectric constant display information E1 and E2 stored in the storage unit 34 as described above.
(I) The dielectric constant ε1 represented by the first dielectric constant display information E1 is an average per unit volume (unit volume) in the region where the folded parallel two-wire transmission line 10 is disposed in the medium 20. An average dielectric constant ε1g determined based on the typical moisture content g, a dielectric constant ε1m determined based on the type of the medium 20, and a folded parallel two-wire transmission line 10 in the medium 20 are disposed. The folded parallel two-wire transmission line 10 in the medium 20 that is determined by the sum (ε1g + ε1m + ε1n) and the average dielectric constant ε1n determined by the salinity in the region as an element, and that sum (ε1g + ε1m + ε1n) The average dielectric constant ε1g determined with the average moisture content g per unit volume (unit volume) in the region where the is disposed as the element and the dielectric constant ε1m determined with the type of the medium 20 as the element Is substantially independent of the frequency f1 of the first frequency signal S1 transmitted to the folded parallel two-line transmission line 10 when the dielectric constant ε1 is obtained, but is determined by the type of the medium 20 as an element The dielectric constant ε1n determined by the salinity and the like in the other part of the dielectric constant ε1m and the area where the folded parallel two-line transmission line 10 is arranged in the medium 20 is generally dependent on the frequency f. When the dielectric constant is represented by a functional expression of ε (f) and the imaginary number is represented by j, the frequency of the first frequency signal S1 when the dielectric constant ε1 is obtained as represented by the functional expression of jε (f). (ii) The dielectric constant ε2 represented by the second dielectric constant display information E2 is equal to the dielectric constant ε1 represented by the first dielectric constant display information E1. Unit volume (unit volume) in the area where the folded parallel two-wire transmission line 10 is arranged ) The dielectric constant ε2g determined with the average water amount g per element as an element, the average dielectric constant ε2m determined with the type of the medium 20 as an element, and the folded parallel two-wire transmission line 10 in the medium 20 The folded parallel two-line transmission path in the medium 20 that is determined by the sum (ε2g + ε2m + ε2n) and the sum (ε2g + ε2m + ε2n) determined with the salinity and the like in the arranged region as an element 10 is a dielectric constant ε2g determined with an average moisture content g per unit volume (unit volume) in a region where 10 is arranged as an element and a part of the dielectric constant ε2m determined with the type of the medium 20 as an element, Although it does not substantially depend on the frequency f2 of the second frequency signal S2 transmitted to the folded parallel two-wire transmission line 10 when the dielectric constant ε2 is obtained, the type of the medium 20 is determined as an element. The average dielectric constant ε2n determined by the salinity and the like in the other part of the dielectric constant ε2m and the area where the folded parallel two-line transmission line 10 in the medium 20 is arranged is the value obtained when the dielectric constant ε2 is obtained. Depends on the frequency f2 of the second frequency signal S2, and (iii) Therefore, both of the dielectric constants ε1 and ε2 represented by the first and second dielectric constant display information E1 and E2, respectively, A unit in the region of the medium 20 where the folded parallel two-line transmission line 10 is affected and is affected by factors such as salinity included in the region where the folded parallel two-line transmission line 10 is arranged. For example, when the dielectric constants ε1 and ε2 respectively represented by the first and second dielectric constant display information E1 and E2 are used, the moisture amount g per volume (unit volume) is not correctly represented. As shown, the horizontal axis On the coordinates with the frequency f and the dielectric constant ε on the vertical axis, the dielectric constant ε1 at the first frequency f1 and the dielectric constant ε2 at the second frequency f2 are plotted, and the line L connecting these plots is represented by the frequency f. If it is extended until it intersects with a vertical line (vertical axis) passing through a point of 0, and the dielectric constant at the intersection is read, the folded parallel two-wire transmission line 10 of the medium 20 is arranged. It is clear that the region represents an average dielectric constant ε0 that does not depend on the frequency, and the above-described coordinate line L shown in FIG. 2 represents the dielectric constant ε1 at the first frequency f1 and It is also clear that the dielectric constant ε2 at the second frequency f2 can be used to express it by a linear function equation, and if this linear function equation is used, the dielectric constant ε0 independent of the frequency can be obtained by calculation. Because (Iv) The first and second dielectric constant display information E1 and E2 read by the computer device 30 are used, and the calculation is performed by the processor 32 using the dielectric constants ε1 and ε2 respectively represented by the information. The dielectric constant display information E0 representing the average dielectric constant ε0 having no frequency dependency in the region where the 20 folded parallel two-line transmission lines 10 are arranged is generated.

  Next, in the computer device 30, the average dielectric constant ε0 having no frequency dependency in the region where the folded parallel two-line transmission line 10 of the medium 20 represented by the dielectric constant display information E0 just generated is arranged. However, as is apparent from the above description, the element of the average moisture amount g per unit volume (unit volume) in the region where the folded parallel two-wire transmission line 10 is arranged in the medium 20 and the medium 20 The element of the medium 20 is an element that is known or is known in advance. For this reason, the moisture amount g is expressed by the dielectric constant ε0 represented by the dielectric constant display information E0. Since it is clear that it can be obtained by the calculation used, the calculation in the processor 32 using the dielectric constant display information E0 generated as described above and using the dielectric constant ε0 represented by the dielectric constant display information E0. In Thus, an average amount of water per unit volume (unit volume) or in a predetermined volume (planned volume) or total volume (total volume) in the area where the folded parallel two-wire transmission line 10 is arranged in the medium 20 Is generated and output from the data input / output unit 35 to the outside.

  As described above, the first embodiment of the method for measuring the amount of water in the medium according to the present invention is the same as the first embodiment of the apparatus for measuring the amount of water in the medium according to the present invention, and the method for measuring the amount of water in the medium according to the present invention. It became clear with the Example of the folding | turning parallel 2-wire transmission line used for an apparatus.

  According to the first embodiment of the method for measuring the amount of moisture in the medium according to the present invention described above, as is apparent from the above description, the medium 20 is obtained using the moisture content display information W obtained as described above. The average amount of water per unit volume (unit volume), or a predetermined volume (planned volume) or a total volume (total volume) in the region where the folded parallel two-wire transmission line 10 is arranged in the medium 20 It can be measured easily and with high accuracy, assuming that it is not affected by factors such as salinity in the region where the folded parallel two-wire transmission line 10 of the medium 20 is disposed.

  As shown in FIG. 1, the automatic gain control circuit 42 is used to supply the first frequency signals S1 and S1 ′ to the same signal level to the phase difference detection circuit 41, and When the second frequency signals S2 and S2 'are also supplied so as to have the same signal level and the first and second phase difference display information D1 and D2 are obtained, the first and second phase differences are obtained. More particularly, the display information D1 and D2 can be obtained as the phase differences θ1 and θ2 are expressed with high accuracy, respectively.

  Further, according to the first embodiment of the device for measuring the amount of water in the medium according to the present invention described above, as is apparent from the above, the amount of water display information W obtained as described above is used. Therefore, the average moisture per unit volume (unit volume) or in the planned volume (planned volume) or total volume (total volume) in the area where the folded parallel two-line transmission line 10 is arranged in the medium 20. The amount can be measured easily and with high accuracy as being unaffected by factors such as the type of medium 20 and salinity in the region where the folded parallel two-line transmission line in the medium 20 is disposed.

Incidentally, according to the water content measuring method and apparatus in the medium according to the present invention described above, because of the use of folding two parallel wire transmission line 10 described above, as is clear from the above, the medium according to the present invention In the region where the folded parallel two-line transmission line 10 in the medium 20 is arranged with the moisture amount display information W obtained as described above, using the moisture amount measuring method and the moisture amount measuring device in the medium. The average amount of water per unit volume (unit volume) or the planned volume (scheduled volume) or the total volume (total volume) is the type of medium 20, and the folded parallel two-wire transmission line 10 in the medium 20 is arranged. It can be measured easily and with high accuracy, assuming that it is not affected by factors such as salinity in the region.

Modification / Change

  In the above description, the folded parallel two-wire transmission line 10 is arranged in the medium 20 so that the signal input end 16 and the signal output end 17 slightly face (project) the surface of the medium 20. Measure the average moisture content per unit volume (unit volume) or in the planned volume (planned volume) or total volume (total volume) in the region where the folded parallel two-wire transmission line 10 in 20 is arranged as such. As shown in FIG. 4, the folded parallel two-wire transmission line 10 is completely buried in the medium 20 including the signal input end 16 and the signal output end 17 in the medium 20. The first and second frequency signals S1 and S2 are connected to the signal input end 16 of the folded parallel two-wire transmission line 10 arranged in this way via the coaxial cable CA. To supply, The first and second frequency signals S1 'and S2' obtained at the signal output end 17 of the folded parallel two-wire transmission line 10 are connected to the automatic gain control circuit 42 and the signal level detection via another coaxial cable CB. As supplied to the circuit 43, or a predetermined volume (planned volume) per unit volume (unit volume) in a region where the folded parallel two-wire transmission line 10 in the medium 20 is buried in the medium 20. It will be apparent that the average moisture content of the total volume (total volume) can also be measured.

  In the above description, (A) (a) the signal input terminal 16 of the folded parallel two-wire transmission line 10 disposed in the medium 20 is connected to the i-th (i = 1, 2,... N; where n is 2 An i-th frequency signal Si having a frequency fi of (an integer above), and (b) the frequency signal Si supplied to the signal input terminal 16 of the folded parallel two-wire transmission line 10 and the folded parallel two-wire transmission line 10. And the i-th frequency signal Si ′ based on the frequency signal Si supplied from the signal output terminal 17 to the signal input terminal 16 of the folded parallel two-line transmission line 10, and the phase difference θi between them is expressed. (C) using the i-th phase difference display information Di, an average of the medium 20 in the region where the folded parallel two-wire transmission line 10 is arranged is generated. The i th dielectric constant display information Ei representing the dielectric constant εi is generated. (B) A plurality of n first, second... Nth dielectric constant display information E1, E2. Using En, an average dielectric constant that has substantially no frequency dependency or little frequency dependency even in the region where the folded parallel two-line transmission line 10 of the medium 20 is disposed A dielectric constant display information E0 representing ε0 is generated. (C) Using the dielectric constant display information E0, a unit volume (unit volume) in a region of the medium 20 where the folded parallel two-wire transmission line 10 is disposed. ) To generate the moisture content display information representing the average moisture content per unit volume or the planned volume (scheduled volume) or the total volume (total volume), and in this case, when n is 2 As an example, n is 3 or more and the medium It is also possible to generate water content display information representing the average water content in the region where the folded parallel two-wire transmission line 10 in 0 is arranged. The dielectric constant display information E0 representing the dielectric constant ε0 is generated using the first, second, third... Dielectric constant display information E1, E2, E3... It is clear that the accuracy can be obtained with higher accuracy than in the case of the embodiment of the present invention. Therefore, the average amount of moisture in the region where the folded parallel two-line transmission line 10 in the medium 20 is arranged is obtained. The displayed water content display information can be obtained with higher accuracy than in the case of the above-described embodiment of the present invention.

  Further, in the above description, the case where the folded parallel two-wire transmission path 10 configured using the U-shaped conductor 13 and the linear conductor 15 is used as the folded parallel two-line transmission path has been described. The parallel two-wire transmission line is bent into a U-shape, and the two-wire free end on one end side is used as a signal input end, and the two-wire free end on the other end side is used as a signal output end. A two-wire transmission line is used, and such a folded parallel two-wire transmission line can be used in place of the folded parallel two-wire transmission line 10, and various modifications can be made without departing from the spirit of the present invention. Will be able to.

  Using the method and apparatus for measuring the amount of water in the medium according to the present invention and the folded parallel two-wire transmission line used therefor, soil, fertilizer, mountain forest land, water source, creation land, pile of waste in the waste treatment plant, It is possible to easily measure an average amount of water in a region where a folded parallel two-wire transmission line is disposed in a medium using food, raw materials thereof, and the like.

1 is a schematic system diagram showing a first embodiment of a method and apparatus for measuring the amount of water in a medium according to the present invention. It is a figure which shows the relationship of the dielectric constant (epsilon) with respect to the frequency f with which it uses for description of the 1st Example of the moisture content measuring method and apparatus in the medium by this invention. It is a rough-line perspective view which shows the return | turnback parallel 2 wire transmission line used for the moisture content measuring method and apparatus in the medium by this invention. It is a rough-line system diagram which shows the other Example of the moisture content measuring method in the medium by this invention, and an apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Folding parallel 2 wire transmission path 11a, 11b Straight part 12 Folding part 13 U-shaped conductor 14 Insulating support board 15 Linear conductor 16 Signal input terminal 17 Signal output terminal 20 Medium 30 Computer apparatus 31 Bus 32 Processor 33 Program storage Unit 34 storage unit 35 data input / output unit 36 control voltage output unit 37 AD conversion unit 40 variable frequency signal generation circuit 41 phase difference detection circuit 42 automatic gain control circuit 43 signal level detection circuit 44 difference output circuit

Claims (4)

A folded parallel two-wire transmission line having a signal input end and a signal output end is disposed in the medium whose moisture content is to be measured,
An i-th frequency signal Si having an i-th (i = 1, 2,... N; where n is an integer of 2 or more) frequency fi is supplied to a signal input terminal of the folded parallel two-wire transmission line;
The frequency signal Si supplied to the signal input terminal of the folded parallel two-wire transmission line and the signal input terminal of the folded parallel two-wire transmission line obtained from the signal output terminal of the folded parallel two-wire transmission line Using the i-th frequency signal Si ′ based on the frequency signal Si, and generating i-th phase difference display information Di representing the phase difference θi between them,
Using the i-th phase difference display information Di, the i-th dielectric constant display information Ei representing the average dielectric constant εi in the region where the folded parallel two-line transmission path of the medium is arranged. Generate
A series of processes of supplying the i-th frequency signal Si to the signal input end of the folded parallel two-wire transmission line, generating the i-th phase difference display information Di, and generating the i-th dielectric constant display information Ei , By using a plurality of n first, second... Nth dielectric constant display information E1, E2... N generated by performing i with 1, 2,. Dielectric representing an average dielectric constant ε0 that has substantially no frequency dependence or little frequency dependence even in the region where the folded parallel two-line transmission line of the medium is arranged The rate display information E0 is generated,
A medium for generating moisture amount display information representing an average amount of moisture in an area of the medium in which the folded parallel two-line transmission line is arranged, using the dielectric constant display information E0. Method of measuring the amount of water in the inside. In the method for measuring the amount of water in the medium according to claim 1,
2. A method for measuring a moisture content in a medium, wherein n is 2. A folded parallel two-wire transmission line having a signal input end and a signal output end arranged in a medium whose moisture content is to be measured;
A plurality of first, second... Nth frequencies respectively having first, second... Nth (where n is an integer equal to or greater than 2) frequencies supplied to the signal input end of the folded parallel two-wire transmission line. Frequency signal generating means for generating the frequency signals S1, S2,.
The i-th (i = 1, 2,... N) frequency signal Si supplied to the signal input terminal of the folded parallel two-wire transmission line and the i-th signal at the signal input terminal of the folded parallel two-wire transmission line. The i-th position representing the phase difference θi between them by using the i-th frequency signal Si ′ obtained from the signal output end of the folded parallel two-line transmission line based on the supply of the frequency signal Si. Phase difference display information generating means for generating phase difference display information Di;
Using the i-th phase difference display information, i-th dielectric constant display information Ei representing an average dielectric constant εi in the region where the folded parallel two-wire transmission line of the medium is arranged is generated. A dielectric constant display information generating means,
A series of processes of supplying the i-th frequency signal Si to the signal input end of the folded parallel two-wire transmission line, generating the i-th phase difference display information Di, and generating the i-th dielectric constant display information Ei Of the medium using a plurality of n first, second,... Nth dielectric constant display information E1, E2. A dielectric constant display representing an average dielectric constant ε0 that has substantially no frequency dependence or little frequency dependence even in the region where the folded parallel two-wire transmission line is arranged. Dielectric constant display information generating means for generating information E0;
Water content display information generating means for generating water content display information representing an average water content in a region of the medium in which the folded parallel two-wire transmission line is arranged, using the dielectric constant display information E0. A device for measuring the amount of moisture in a medium. In the water content measuring apparatus in the medium according to claim 3,
2. A device for measuring a moisture content in a medium, wherein n is 2.

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