CN205157482U - Soil moisture measuring device - Google Patents

Abstract

The utility model discloses a soil moisture measuring device, including casing, inside circuit module, fixed disk (110) and 4 piece at least probe (111), in inside circuit module arranged the casing in, the front end at the casing was installed to the fixed disk, and probe fixing is on the fixed disk, and the front end of probe stretches out from the place ahead of casing, inside circuit module passes through coaxial cable (107) and links to each other with the probe. The probe in, probe is installed in the center of fixed disk department, many probes are in addition evenly arranged along the circumference of fixed disks. This soil moisture measuring device measurement accuracy is high.

Description

A kind of soil humidity measuring device

Technical field

The utility model relates to a kind of soil humidity measuring device.

Background technology

Soil humidity sensor (having another name called soil moisture meter) mainly utilizes the specific inductive capacity measuring soil to measure the device of volumetric soil water content.The porous medium that soil is made up of air, solid and water, wherein the specific inductive capacity of water is approximately 80, and the specific inductive capacity of solid is approximately 4, and the specific inductive capacity of air is approximately 1.Therefore, soil dielectric constant determines primarily of soil moisture content.

Soil moisture measurement device, is formed primarily of signal source (i.e. oscillator), transmission line and probe three part.By signal source generation signal through transmission line to probe, due to the tie point impedance discontinuity of transmission line and probe, therefore reflect at this point.The intensity of reflection spot signal is relevant with the reflection coefficient at this place, and reflection coefficient is relevant with the size of transmission line impedance primarily of probe impedance.When probe inserts in tested soil, the impedance of probe changes along with the change of water cut, and the impedance of transmission line is certain.Therefore, the signal at the tie point place of probe and transmission line changes with change of moisture content.

The impedance of the probe of soil moisture sensor changes with the content of soil moisture, changes the reflection coefficient at the tie point place of concentric cable and probe, therefore causes the change of the amplitude of this tie point place voltage.Therefore, the water cut of soil can be reflected according to the voltage difference at concentric cable two ends, or adopt electric current to export the water cut of reflect soil.Therefore agriculture field and meteorological field is widely used in.

There is following shortcoming in current home products:

1, for long range propagation, in the process adopting voltage, electric current to export, line loss is large, and parts easily damage and data stability is poor, thus affect degree of accuracy.

2, accuracy effect cannot realize the one_to_one corresponding of robotization, increases man power and material's cost.

Conventional application, mostly be agriculture aspect, bury underground more shallow, product waterproof property is less demanding, and water pressure resistance test deficiency also cannot reach IP68 grade.

Therefore, be necessary to design a kind of soil humidity measuring device.

Utility model content

Technical problem to be solved in the utility model is to provide a kind of soil humidity measuring device, and this soil humidity measuring device measuring accuracy is high.

The technical solution of utility model is as follows:

A kind of soil humidity measuring device, is characterized in that, comprise housing, internal circuit blocks, shaft collar (110) and at least 4 probes (111);

Internal circuit blocks is placed in housing, and shaft collar is arranged on the front end of housing, and probe is fixed on shaft collar, and the front end of probe is stretched out from the front of housing;

Internal circuit blocks is connected with probe by concentric cable (107).Concentric cable constituent material: the copper conductors of insulating material isolation.

In described probe, a probe is arranged on the center of shaft collar, and many probes are in addition evenly arranged along the circumference of shaft collar.

Described probe is at least 3.Preferential 4.

Described housing is docked by the first cylindrical housings (104) and the second cylindrical housings (109) and forms; First cylindrical housings is for holding internal circuit blocks and concentric cable; Second cylindrical housings is for holding shaft collar; The tail end of the first cylindrical housings is provided with the mechanical plug (102) of band communication data line (101).

The tail end of probe stretches out from the back side of shaft collar.[and the tail end of probe is screwed and sealant pouring and sealing]

Probe interior circuit comprises data processing module (105), oscillator (106) and digital voltmeter (108); The signal output part of oscillator is connected with concentric cable; The input end of digital voltmeter is connected with concentric cable, the output termination data processing module of digital voltmeter.

Also be provided with temperature sensor and conversion, compensating cable in housing, temperature sensor and conversion, compensating cable are all connected with data processing module (i.e. central processing unit).

Described soil humidity measuring device is also provided with signal amplification circuit, analog to digital conversion circuit, storer, unique number maker, RS485 change-over circuit and signal output part circuit;

The output terminal of digital voltmeter is connected with data processing module with analog to digital conversion circuit by signal amplification circuit successively, storer, unique number maker are all connected with data processing module with RS485 change-over circuit, and signal output apparatus is connected with RS485 change-over circuit.

Data processing module adopt digital processing chip build, also can adopt integrated chip, as single-chip microcomputer or DSP etc., data processing module be embodied as existing mature technology.

The improvements of soil humidity sensor method of testing be following some: one: increase sensor and can demarcate and writing function, understand each sensor unique attribute record and be applied to actual environment, ensure the accuracy of test; Domestic different local soil is different, and soil property has certain influence to volumetric water content, and user can adopt traditional oven drying method, relative method to carry out secondary demarcation according to actual conditions, really accomplishes to use sensor with suiting measures to local conditions; Two, because of impact that variation of ambient temperature is brought sensor, also be the reason affecting precision, sensor internal set temperature sensor, can realize recording and the function of self-recision data, direct compensation is affected on temperature, the precision of the data again ensured and accuracy; Three, sensor exports the physical quantity for digital signal, reduces the error of artificial conversion and record, ensure that the absolute reliability of data.

Soil humidity sensor is made up of precision measurement probe, ABS material moulding, concentric cable, circuit processor, temperature sensor, annular fixing member, water conservancy project cable; Structural member adopts ring current ring design, improves product stability;

Beneficial effect:

Soil humidity measuring device of the present utility model, [electric current loop is exactly shaft collar to adopt four probes and unique electric current loop form, 4 probe signals are averaged, precision is high], ensure that data are reliable and stable, especially directly output digit signals (physical quantity), facilitate long-range data stable transfer, the internal modifications function of intelligent test and record, user can realize intelligent secondary and demarcate, and increases the accuracy of sensor; The soil humidity sensor of integration increases mechanical seal in addition, and adopts process for filling colloid into improve soil humidity sensor classification of waterproof, can reach IP68.

The utility model is applicable to measurement data pinpoint accuracy, accuracy, soil moisture content measurement mechanism that water resistance is strong, the soil moisture of buried or long range propagation preferably and Humidity Detection.

The device provides a kind of soil moisture, humidity integrated transducer, improve attached cable ring design, increase the stability of sensor, increase the setting of secondary demarcation and the function of temperature compensation, ensure degree of accuracy and the accuracy of sensor, Direct Digital signal exports, more ensure that the data reliability of long range propagation, tight structurally waterproof design, has greatly opened up the popularity in sensor application field, has also increased the serviceable life of sensor.Precision can reach ± 2%F.S, can ensure long-time stability, and this sensor has good water resistance, and classification of waterproof can reach IP68.

The utility model can be widely applied to other demand fields except agricultural, as: the rugged surroundings field such as high fill foundation process, mountain area New Town Construction, high filling subgrade basis, airport construction, port and pier construction in civil engineering work monitoring field.

Accompanying drawing explanation

Fig. 1 is the structural principle block diagram of the utility model embodiment;

Fig. 2 is the fundamental diagram of the utility model embodiment;

Fig. 3 is the schematic block circuit diagram of the utility model embodiment;

Fig. 4 is that the user of the utility model embodiment uses correction process flow diagram;

Label declaration: 101-communication data line, 102-mechanical plug, 103-sealing gasket, 104-first cylindrical housings, 105-data processing module, 106-oscillator, 107-concentric cable, 108-digital voltmeter, 109-second cylindrical housings, 110-shaft collar, 111-probe.

Embodiment

Below with reference to the drawings and specific embodiments, the utility model is described in further details:

Embodiment 1:

As Fig. 1-4, a kind of soil humidity sensor, comprising: the first cylindrical housings 104, second cylindrical housings 109, shaft collar 110, probe 111, oscillator 106, concentric cable 107, digital voltmeter DVM108, data processing module 105, mechanical plug 102, sealing gasket 103, communication data line 101, temperature sensor, serial storage chip, conversion compensating circuit.

Described first cylindrical housings 104 one end and the second cylindrical housings 109 are to slotting seamless link, and the other end is threaded with mechanical plug 102; Probe 111 is through fixing bottom shaft collar 110 and the second cylindrical housings 109;

Described first cylindrical housings 104 and the second cylindrical housings 109 are working of plastics;

Described probe 111 is conductive material, is 4; Middle 1, circumference is uniformly distributed other 3; The probe of each periphery and middle must be worth after be averaged, 4 probe measurement volumetric water contents are more scientific, more accurately.

Described sealing gasket 103, is placed on mechanical plug 102 between the first cylindrical housings screw thread is fixing;

Treatment circuit comprises oscillator 106, concentric cable 107, digital voltmeter DVM108, analog to digital conversion circuit, signal amplifier, data processing module, serial storage chip, serial conversion compensation chips, temperature sensor, unique encodings maker, 485 change-over circuits, to the signal from high frequency oscillator 106, by concentric cable 107, be transferred to probe 111, due to the tie point impedance discontinuity of concentric cable 107 and probe, therefore reflect at this point, because the water cut of soil is different, therefore the signal amplitude of this point is different, concentric cable two end signal is carried out peakvalue's checking respectively in digital voltmeter DVM108, the peak value detected is sent in signal amplification circuit respectively, through analog to digital conversion circuit, give data processing module, data processing module carries out logical and numerical operation to the voltage signal amplified, and compensates according to the output temperature of temperature sensor, exports the physical quantity of measured signal, temperature sensor is connected with data processing module, electricity can be write read-only serial storage chip and be connected with microdata processor (i.e. data processing module), according to the instruction of microdata processor, stores or recalls data-signal, RS485 change-over circuit is connected with the serial line interface of data processing module, according to the instruction from data processing module, externally sends or receives data.User according to the different soil property in locality and the reason such as demand requiring reduced mass water percentage, can carry out secondary demarcation and compensation, will demarcate file more accurately, be uploaded to data processing module and revise.

Humidity sensor of the present utility model, for structurally waterproof problem, improves the process of total sealing, the mode that sensor outgoing line part adopts sealing structure and pad to combine, and sensor body structure and base portion adopt pyramidal structure; Sensor probe part adopt anti-twisting structural design and O type circle design, ensure each may with the ripe waterproof technique of extraneous contact part.

Above-describedly be only preferred embodiment of the present utility model; be understood that; the explanation of above embodiment just understands method of the present utility model and core concept thereof for helping; and be not used in restriction protection domain of the present utility model; all any amendments, equivalent replacement etc. made within thought of the present utility model and principle, all should be included within protection domain of the present utility model.

Claims (8)

1. a soil humidity measuring device, is characterized in that, comprises housing, internal circuit blocks, shaft collar (110)

At least 4 probes (111);

Internal circuit blocks is placed in housing, and shaft collar is arranged on the front end of housing, and probe is fixed on shaft collar, and the front end of probe is stretched out from the front of housing;

Internal circuit blocks is connected with probe by concentric cable (107).

2. soil humidity measuring device according to claim 1, is characterized in that, in described probe, a probe is arranged on the center of shaft collar, and many probes are in addition evenly arranged along the circumference of shaft collar.

3. soil humidity measuring device according to claim 2, is characterized in that, described probe is at least 3.

4. soil humidity measuring device according to claim 1, is characterized in that, described housing is docked by the first cylindrical housings (104) and the second cylindrical housings (109) and forms; First cylindrical housings is for holding internal circuit blocks and concentric cable; Second cylindrical housings is for holding shaft collar; The tail end of the first cylindrical housings is provided with the mechanical plug (102) of band communication data line (101).

5. soil humidity measuring device according to claim 1, is characterized in that, the tail end of probe stretches out from the back side of shaft collar.

6. the soil humidity measuring device according to any one of claim 1-5, is characterized in that, probe interior circuit comprises data processing module (105), oscillator (106) and digital voltmeter (108); The signal output part of oscillator is connected with concentric cable; The input end of digital voltmeter is connected with concentric cable, the output termination data processing module of digital voltmeter.

7. soil humidity measuring device according to claim 6, is characterized in that, be also provided with temperature sensor and conversion, compensating cable in housing, temperature sensor is all connected with data processing module with conversion, compensating cable.

8. soil humidity measuring device according to claim 7, is characterized in that, is also provided with signal amplification circuit, analog to digital conversion circuit, storer, unique number maker, RS485 change-over circuit and signal output part circuit;

The output terminal of digital voltmeter is connected with data processing module with analog to digital conversion circuit by signal amplification circuit successively, storer, unique number maker are all connected with data processing module with RS485 change-over circuit, and signal output apparatus is connected with RS485 change-over circuit.