CN2396398Y - Capacitive type soil humidity meter - Google Patents
Capacitive type soil humidity meter Download PDFInfo
- Publication number
- CN2396398Y CN2396398Y CN 99232565 CN99232565U CN2396398Y CN 2396398 Y CN2396398 Y CN 2396398Y CN 99232565 CN99232565 CN 99232565 CN 99232565 U CN99232565 U CN 99232565U CN 2396398 Y CN2396398 Y CN 2396398Y
- Authority
- CN
- China
- Prior art keywords
- circuit
- capacitance
- soil humidity
- operational amplifier
- type soil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
The utility model relates to a capacitance soil humidity tester, which belongs to the improvement of testing instruments of soil humidity. The utility model is characterized in that the top end of a measuring probe is a metal guide cone (1), the lower part of a probe rod (6) is connected with one sensor capacitance body composed of a humidity absorption medium (4) arranged between a porous metal tube (2) and an insulated metal rod (3) in the center of the porous metal tube (2). Electrode lead wires (5) of the porous metal tube (2) and the insulated metal rod (3) are uniformly connected with a host machine measuring circuit via an inner cavity lead-out probe of the probe rod (6). The instrument can carry out the measurement of original conformation and position to soil of different depth.
Description
The utility model is a kind of capacity type soil humidity analyzer, belongs to the design and manufacturing technology field of field soil hygroscopy instrument.
In the measuring soil moisture method, though the most classical oven drying method is measured accurately, sampling, oven dry are time-consuming, bothersome, are not suitable for the direct measurement, particularly ortho states-in-site detecting of field soil humidity.
The direct mensuration of field soil humidity includes conductance method (gypsum electrode method), radiant heat method (electrothermal way), microwave method, depressimeter method, NEUTRON METHOD mensuration.Its weak point is: the depressimeter method only can be measured the moisture of soil capillary section.Because soil conductivity is not only relevant with soil moisture, and relevant with ion concentration and kind, so conductance method is applied fertilizer when being used for the agricultural land soil hygroscopy and the influence of irrigation water water quality is bigger, and its accuracy of measurement is lower.Also there are certain limitation in electrothermal way, microwave method at aspects such as method of operating, reappearance, investigation depths.The NEUTRON METHOD measurement range is wide, the precision height, but because the price height need carry out nuclear radiation protection in storage, carrying with in using, applicable surface is narrower.NEUTRON METHOD is measured the influence that is subjected to soil organic matter content simultaneously, is not suitable for the hygroscopy of topsoil soils.
The purpose of this utility model is to remedy above-mentioned the deficiencies in the prior art and a kind of insertion type probe is provided, and forms the capacity type soil humidity analyzer of capacitance body structure as capacitor dielectric with the moisture absorption medium material.
The purpose of this utility model can reach by following measure: the capacity type soil humidity analyzer that is made of measuring sonde, transmission cable and measurement host circuit, the measuring sonde top is the metal leading cone, the probe rod bottom connect one by the insulated metal rod at porous metals Guan Yuqi center and between the sensor capacitance body formed of moisture absorption medium, the contact conductor of porous metals pipe and insulated metal rod is drawn probe by the inner chamber of probe rod and is connected with the measurement host circuit.
The purpose of this utility model can also reach by following measure: measure host circuit and comprise capacitor compensating circuit, temperature-compensation circuit, current rectifying and wave filtering circuit between capacitance measurement circuit, sensor primary capacitance and the transfer cable wire of being made up of sine wave signal generator, integrated operational amplifier; In the host circuit by integrated operational amplifier A
3With with C
xAs the measured capacitance of sensor and the calibration capacitor C of decision measurement range
nConstitute capacitance measurement circuit, resistance R
6Keep A
3The feedback direct current channel that steady-working state is arranged; In the host circuit by integrated operational amplifier A
2With capacitor C
pWith regulator potentiometer R
wConstitute capacitor compensating circuit between sensor primary capacitance and transfer cable wire; In the host circuit by integrated operational amplifier A
4With resistance R
tConstitute temperature-compensation circuit; In the host circuit by integrated operational amplifier A
5With diode D
1, D
2And resistance R
13, capacitor C
3Constitute current rectifying and wave filtering circuit; Moisture absorption medium is a glass wool.
Description of drawings:
Fig. 1 is the measuring sonde structural drawing
Fig. 2 is a measuring sonde capacitance body structure amplification profile
Fig. 3 is for measuring the host circuit structural drawing
The utility model is described further below in conjunction with accompanying drawing:
As depicted in figs. 1 and 2: measuring sonde bar (6) top is metal leading cone (1), probe rod (6) bottom connect one by porous metals pipe (2) and insulated metal rod (3) and between the sensor capacitance body Cx that forms of moisture absorption medium (4), porous metals pipe (2) is single shielding line with the contact conductor (5) of insulated metal rod (3), by the wiring gold (7) that is drawn out to sound end in probe rod (6) pipe, be welded on when assembling at last in the measurement cable gang socket (8) of terminal box (7), probe is connected with host circuit.The effective stainless steel of leading cone and porous metals is made; The insulated metal rod is made of copper product; Plastic material car system or injection mo(u)lding that probe rod is anti-aging with nylon material or other, insulate, have certain physical strength.Leading cone can strengthen the pressure that probe buries, and makes it insert in the soil easily; The maximum embedded depth of the length decision probe of probe rod.
As shown in Figure 3: measure host circuit and comprise by sine wave signal generator G integrated operational amplifier A
1-A
5Capacitor compensating circuit, temperature become compensating circuit, current rectifying and wave filtering circuit between capacitance measurement circuit, sensor primary capacitance and the transfer cable wire of forming, and all are contained in the main case.Integrated operational amplifier A
1Be follower, C
1Be capacitance, its effect is the influence of DC component to measuring that the erasure signal generator is produced.By integrated operational amplifier A
2With capacitor C
pWith potentiometer R
wConstitute capacitor compensating circuit between sensor primary capacitance and transfer cable wire, integrated operational amplifier A
2With integrated operational amplifier A
1The sine wave signal of output is anti-phase, capacitor C
pBe the building-out capacitor of sensor primary capacitance and transmission cable line capacitance, regulator potentiometer R
wJust can reach the purpose of capacitance compensation between sensor primary capacitance and transfer cable wire, make integrated operational amplifier A
3Output valve only be sensor measures capacitance C
xChange the capacitance variations value that produces because of soil moisture.By integrated operational amplifier A
3With with C
xAs the measured capacitance of sensor and the calibration capacitor C of decision measurement range
nConstitute capacitance measurement circuit, resistance R
6Keep A
3The feedback direct current channel that one steady-working state is arranged.By integrated operational amplifier A
4With resistance R
tConstitute temperature-compensation circuit.Thermistor R
tResistance change with the variation of the tested soil moisture, regulate integrated operational amplifier A
4The closed loop enlargement factor, thereby the compensation soil moisture to sensor measures capacitance C
xInfluence.By integrated operational amplifier A
5With diode D
1, D
2And resistance R
13, capacitor C
3Constitute current rectifying and wave filtering circuit, the AC signal of measuring output is become direct current signal U.Offer display, capacitor C
2Be capacitance, avoid integrated operational amplifier A
3, A
4The DC component that circuit produces is to integrated operational amplifier A
5Influence.
Integrated operational amplifier A
1-A
4Be broadband high input impedance operational amplifier, A
5Be the broadband low drifting operating amplifier.To portable instrument with dry cell power supply, integrated operational amplifier A
1-A
5Should be the low power amplifier operational amplifier in broadband.Capacitor C
n, C
pBe the accurate electric capacity of low-temperature coefficient, resistance R
tBe posistor, capacitor C
3Be electrochemical capacitor, diode D
1, D
2Be detector diode.Resistance in the circuit is metalfilmresistor.
The capacity type soil humidity analyzer, the sensor capacitance body C that the dielectric material (4) that moisture absorption is fast, desorb is also fast between the insulated metal rod (3) at probe bottom employing porous metals pipes (2) and its center forms as capacitor dielectric
xStructure is inserted the non-kapillary water-bearing section in the soil, when soil moisture changes, as the probe sensor capacitor C
xCapacitance significant change appears, utilize this characteristic, after the related coefficient that records soil moisture and capacitance body capacitance variation, just can determine the humidity of soil by measuring its capacitance, it measures with the elasticity of soil irrelevant.
The utlity model has following advantage: 1, measures the non-capillary tube segment water content of soil and have fabulous effect, and can be connected mutually with the depressimeter measurement category. 2, soil salt content is very little to determination influences. 3, probe is for plug in construction, and leading cone has strengthened the pressure that probe buries, and it is inserted in soil easily, can be to not Soil with the degree of depth is implemented ortho states-in-site detecting.
Claims (7)
1, a kind of capacity type soil humidity analyzer that constitutes by measuring sonde, transmission cable and measurement host circuit, it is characterized in that the measuring sonde top is metal leading cone (1), probe rod (6) bottom connect one by porous metals pipe (2) and insulated metal rod (3) and between the sensor capacitance body C that forms of moisture absorption medium (4)
x, the contact conductor (5) of porous metals pipe (2) and insulated metal rod (3) is drawn probe by the inner chamber of probe rod (6) and is connected with the measurement host circuit.
2, capacity type soil humidity analyzer as claimed in claim 1 is characterized in that measuring host circuit and comprises by sine wave signal generator, integrated operational amplifier A
1-A
5Capacitor compensating circuit, temperature-compensation circuit, current rectifying and wave filtering circuit between capacitance measurement circuit, sensor primary capacitance and the transfer cable wire of forming.
3, capacity type soil humidity analyzer as claimed in claim 1 or 2 is characterized in that in the host circuit by integrated operational amplifier A
3With with C
xAs the measured capacitance of sensor and the calibration capacitor C of decision measurement range
nConstitute capacitance measurement circuit, resistance R
6Keep A
3The feedback direct current channel that certain duty is arranged.
4, capacity type soil humidity analyzer as claimed in claim 1 or 2 is characterized in that in the host circuit by integrated operational amplifier A
2With capacitor C
pWith regulator potentiometer R
wConstitute capacitor compensating circuit between sensor primary capacitance and transfer cable wire.
5, capacity type soil humidity analyzer as claimed in claim 1 or 2 is characterized in that in the host circuit by integrated operational amplifier A
4With resistance R
tConstitute temperature-compensation circuit.
6, capacity type soil humidity analyzer as claimed in claim 1 or 2 is characterized in that in the host circuit by integrated operational amplifier A
5With diode D
1, D
2And resistance R
13, capacitor C
3Constitute current rectifying and wave filtering circuit.
7, capacity type soil humidity analyzer as claimed in claim 1 is characterized in that moisture absorption medium (4) is a glass wool.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99232565 CN2396398Y (en) | 1999-09-08 | 1999-09-08 | Capacitive type soil humidity meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99232565 CN2396398Y (en) | 1999-09-08 | 1999-09-08 | Capacitive type soil humidity meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2396398Y true CN2396398Y (en) | 2000-09-13 |
Family
ID=34021228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99232565 Expired - Fee Related CN2396398Y (en) | 1999-09-08 | 1999-09-08 | Capacitive type soil humidity meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2396398Y (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105067678A (en) * | 2015-07-31 | 2015-11-18 | 重庆市长寿区大嘉富水果种植股份合作社 | Soil humidity tester |
| CN107064243A (en) * | 2017-04-18 | 2017-08-18 | 武汉大学 | A kind of clay dielectric capacitor type soil matrix gesture measuring method |
| CN107091864A (en) * | 2017-04-18 | 2017-08-25 | 武汉大学 | Condenser type soil matrix gesture real-time measurement system |
| WO2020217243A1 (en) * | 2019-04-26 | 2020-10-29 | Korol Oleg | Water absorbent tensiometer for determining moisture levels for irrigation |
| WO2021244897A1 (en) * | 2020-06-04 | 2021-12-09 | Plantcare Ag | Moisture measuring device having an antibacterial effect |
-
1999
- 1999-09-08 CN CN 99232565 patent/CN2396398Y/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105067678A (en) * | 2015-07-31 | 2015-11-18 | 重庆市长寿区大嘉富水果种植股份合作社 | Soil humidity tester |
| CN107064243A (en) * | 2017-04-18 | 2017-08-18 | 武汉大学 | A kind of clay dielectric capacitor type soil matrix gesture measuring method |
| CN107091864A (en) * | 2017-04-18 | 2017-08-25 | 武汉大学 | Condenser type soil matrix gesture real-time measurement system |
| CN107091864B (en) * | 2017-04-18 | 2020-01-14 | 武汉大学 | Capacitance type soil matrix potential real-time measuring system |
| WO2020217243A1 (en) * | 2019-04-26 | 2020-10-29 | Korol Oleg | Water absorbent tensiometer for determining moisture levels for irrigation |
| WO2021244897A1 (en) * | 2020-06-04 | 2021-12-09 | Plantcare Ag | Moisture measuring device having an antibacterial effect |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |