CN103604717B - Measure volume displacement method and the equipment of soil quality moisture content - Google Patents

Abstract

The present invention provides a kind of volume displacement method measuring soil quality moisture content, specifically comprises the following steps that by soil sample to be measured for arbitrary volume loading volume be known constant-volume container, claims quality of soil sample to be measured；In the constant-volume container equipped with soil sample to be measured, fill water, weigh after topped up with water the gross mass of soil sample and water in constant-volume container；Soil quality moisture content is calculated according to formula.The present invention also provides for the equipment used by the inventive method, is made up of constant-volume container, weighing-appliance, water injection equipment, and wherein constant-volume container is used for holding soil sample to be measured, and water injection equipment is for toward water filling in constant-volume container, and weighing-appliance is used for weighing quality.The method of the present invention is applicable to the measurement of water ratio of any quality soil, and operating process is simple, convenient, overcomes that to measure the oven drying method of moisture content relatively time consuming and be not suitable for field work, and combustion method consumes the problem that the energy, certainty of measurement are relatively low.

Description

Measure volume displacement method and the equipment of soil quality moisture content

Technical field

The present invention relates to agrology field, be specifically related to a kind of soil quality moisture content measured Volume displacement method and equipment.

Background technology

Soil quality moisture content is the physical quantity characterizing certain depth soil layer dry and wet degree, is agriculture An important parameter in industry production, determining soil moisture is by the base that soil moisture is analyzed Plinth works, and its directly measurement is the basis of correlative study and application, at soil mechanics, work Thing cultivation, field irrigation, ecological environment etc. are studied and particularly significant in practice, so accurately The information that ground obtains soil quality moisture content is particularly important.In particular with water resources crisis day Benefit is prominent, all pays close attention water-saving agriculture research both at home and abroad, soil quality moisture content The most just become the project often measured in water-saving agriculture research.At production and construction, agricultural, water In the engineerings such as profit, need simplicity, quickly mensuration soil quality moisture content.

At present, directly measure the method for soil quality moisture content mainly have drying Weight or Combustion method, as the unique method of directly measurement soil water content, wherein dries and claims quality Method is standard method.Both approaches is the basis of other all indirect measurement methods, is surveying There is in accuracy of measurement the advantage that other indirect measurement method is incomparable.Traditional measurement moisture content Relatively time-consuming of oven drying method and be not suitable for field work；Combustion method consumes the energy, measures essence Spend relatively low.Other indirect measurement methods are (such as TDR, FDR, gamma ray, electric capacity Sensor, Neutron etc.), it is necessary to use one of above two direct measuring method to calibrate And demarcation, exist simultaneously expensive, be difficult to operation, may be bigger etc. many to harm The defect of aspect.Therefore, direct measuring method is extremely important simply and easily.

Summary of the invention

Operation in order to overcome the method measuring soil quality moisture content for a long time to exist is complicated Etc. problem, it is desirable to provide a kind of volume displacement method measuring soil quality moisture content and Equipment.

The principle of the volume displacement method that the present invention measures soil quality moisture content is as follows:

The three-phase mixture that soil is made up of soil particle, water and gas.The quality of air exists Calculating is negligible, so the quality of soil sample to be measured taken is mainly by soil particle quality Determine containing water quality with soil sample to be measured.

Owing to soil sample fills the most still to fill loose the most only to affect the feelings of aeration porosity in soil Condition, do not interfere with soil bulk density, soil particle volume, soil sample to be measured containing water quality, treat Survey the aqueous volume of soil sample, therefore can appoint during sampling and take soil sample to be measured.

Soil sample to be measured for arbitrary volume is loaded in constant-volume container, claim quality of soil sample m to be measured is backward Container fills water, quality obtain topped up with water after in constant-volume container the gross mass of soil sample and water be called M ', now, in container, the quality of material includes that soil particle quality, soil sample to be measured are containing water quality And the quality sum kept the skin wet, then relationship between quality expression formula is:

m'=m_s+m_w+m_r(1)

Wherein, m_rFor the biodiversity supplemented in constant-volume container, unit g.

The process of water filling is by the gas displacement in soil sample and constant-volume container out.The moisture supplemented Quality it is known that original gas-filled space (original soil sample and constant-volume container) is and is injected into The volume of water displacement.According to volume relationship, the aqueous volume of soil sample to be measured and soil can be calculated Soil particle volume sum, for the difference of volume and the volume kept the skin wet of constant-volume container.As following Relational expression:

v_s+v_w=v'-m_r/ρ_w(2)

In soil sample, the quality of soil particle and water is respectively equal to volume and the density of each of which Product.

So obtaining:

$v_s=\frac{m-{\mathrm{\ρ}}_w{v}_0}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}---\left(3\right)$

$v_w=\frac{{\mathrm{\ρ}}_s{v}_0-m}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}---\left(4\right)$

In formula,

$v_0=v^{\′}-\frac{m_r}{{\mathrm{\ρ}}_w}---\left(5\right)$

For soil particle volume and soil sample to be measured aqueous volume sum, unit cm³。

According to soil bulk density and water density, the matter of soil particle and initial aqueous can be obtained Amount:

m_s=v_sρ_s(6)

m_w=v_wρ_w(7)

According to definition, soil moisture content is calculated by following formula:

$\mathrm{\θ}=\frac{m_w}{m_s}\×100\%---\left(\text{8}\right)$

Then the moisture content of any soil is obtained according to formula (6), (7), (8).

$\mathrm{\θ}=\frac{v_w{\mathrm{\ρ}}_w}{v_s{\mathrm{\ρ}}_s}\×100\%---\left(9\right)$

A kind of volume displacement method measuring soil quality moisture content that the present invention provides, specifically Step is as follows:

Soil sample to be measured is loaded constant-volume container known to volume, claims quality of soil sample to be measured；To equipped with The constant-volume container of soil sample to be measured fills water, weighs after topped up with water soil sample and water in constant-volume container Gross mass；According to below equation calculating soil moisture content:

Formula 1:m_r=m'-m

Formula 2:v₀=v'-m_r/ρ_w

Formula 3: $v_s=\frac{m-{\mathrm{\ρ}}_w{v}_0}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}$

Formula 4: $v_w=\frac{{\mathrm{\ρ}}_s{v}_0-m}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}$

Formula 5: $\mathrm{\θ}=\frac{v_{\text{w}}{\mathrm{\ρ}}_w}{v_s{\mathrm{\ρ}}_s}\×100\%$

In formula, m_rThe quality of the water by being injected, m is quality of soil sample to be measured, and m ' is topped up with water Soil sample and the gross mass of water in rear constant-volume container, unit g, v ' is constant-volume container volume, v₀For Soil particle volume and soil sample to be measured aqueous volume sum, v_sFor soil particle volume, v_wFor The aqueous volume of soil sample to be measured, unit cm³；ρ_wFor water density, ρ_sFor soil bulk density, Unit g/cm³；θ is soil quality moisture content, unit %；

Described constant-volume container is by a regular shape and on-deformable container and the liquid of upper end thereof Face locating cover composition, is provided with water filling port on liquid level locating cover, is provided with spilling water in vessel port Mouthful；The volume controlled in container by adding a cover liquid level locating cover in the upper end of container is constant, By water filling port slow liquid make-up in constant-volume container, gap is for discharging beyond constant volume The liquid of vessel volume.

Wherein, temperature is when about 4 DEG C, and the density of water is 1.000g/cm³, in temperature change In the case of Bu great, can be when calculating by water density ρ_wValue 1.000g/cm³；Soil Granule density ρ_sSize is relevant with mineral composition with the chemistry of soil, the grain density of general soil Many 2.6～2.8g/cm³In the range of, the soil bulk density value generally used during calculating is 2.653g/cm³。

Wherein, the shapes such as described constant-volume container is preferably cylindrical, cuboid or polygon prism.

Wherein, the material requirements of described constant-volume container has certain repellency and is unlikely to deform.Pottery Material or general metal material such as aluminium, stainless steel, alloy etc..

Wherein, described in fill water, for the liquid level that adds water in constant-volume container close to constant-volume container mouth, Cover liquid level locating cover, the most inwardly dripped by water filling port to gap and have water droplet to appear as Only.

Wherein, calculating process can be calculated by artificial calculating, calculator calculating, computer, excellent Elect as and the data of mensuration are introduced directly into computer, automatically calculate according to enrolling required formula Soil quality moisture content.

It is a further object of the present invention to provide the volume displacement method measuring soil quality moisture content Equipment used, is made up of constant-volume container, weighing-appliance, water injection equipment；Wherein constant-volume container For holding soil sample to be measured, water injection equipment is for toward water filling in constant-volume container, and weighing-appliance is used for Weigh quality.

Wherein, described weighing-appliance is balance, preferred electron balance.

Wherein, the preferred dropper of described water injection equipment, more preferably glue head dropper.

Wherein, the described preferred computer of calculating equipment.

The present invention also provides for the volume displacement method of described measurement soil quality moisture content and is measuring Application in soil physical properties.

Present invention provide the advantage that:

The volume displacement method measuring soil quality moisture content of the present invention is applicable to any matter Ground, the measurement of water ratio of arbitrary volume/quality soil, operating process is simple, convenient.This Bright method overcomes relatively time-consuming of the oven drying method of traditional measurement moisture content and is not suitable for field Operation, the problem that the combustion method consumption energy, certainty of measurement are relatively low, there is well application Prospect.

The stabilization of equipment performance that the present invention measures the volume displacement method of soil quality moisture content is good, Total matter of soil and water after the initial mass of arbitrary volume/quality soil and water filling can be measured Amount, by being calculated soil quality moisture content, convenient, fast, accurate.

Accompanying drawing explanation

In Fig. 1 embodiment 1, the present invention measures the volume displacement method institute of soil quality moisture content With the structural representation of equipment.

In Fig. 2 embodiment 1, the present invention measures the volume displacement method institute of soil quality moisture content With the constant-volume container structural representation in equipment.

In Fig. 3 embodiment 1, the present invention measures used by the volume displacement method of soil quality moisture content Constant-volume container photo in equipment.

Fig. 4 is volume displacement method and the baking of embodiment 2 this law bright measurement soil quality moisture content The results contrast figure of dry method.

Wherein, 1 is constant-volume container, and 2 is electronic balance, and 3 is glue head dropper, and 4 is water filling port, 5 is gap, and 6 is liquid level locating cover.

Detailed description of the invention

Following example are used for illustrating the present invention, but are not limited to the scope of the present invention.

Embodiment 1 present invention measures the volume displacement method device therefor of soil quality moisture content

The present invention measures the volume displacement method device therefor structure chart of soil quality moisture content such as Shown in Fig. 1, including constant-volume container 1, weighing-appliance electronic balance 2(Shanghai Zhuo Jing electronics section Skill Co., Ltd, model: BSM-5200.2), water injection equipment glue head dropper 3(laboratory normal Simple glass matter glue head dropper).

Wherein, the structural representation of constant-volume container 1 is as in figure 2 it is shown, Fig. 3 is shown in by photo in kind. Constant-volume container 1(includes constant-volume container and the liquid level locating cover two parts removing liquid level locating cover) It is a cylinder shape belt liquid level locating cover container, its liquid level locating cover 6 is provided with water filling port 4, It is provided with gap 5 in vessel port.Constant-volume container 3 internal diameter 75mm, external diameter 81mm, high 63mm, Wall thickness 3mm, the thick 3mm of liquid level locating cover 6.Gap 5 deep 3mm, width 5mm, For to internal cutting 45 °；The a diameter of 2mm of water filling port 4 lower port, upper port diameter is slightly larger than Lower port.Constant-volume container 1 material is metal material.

Embodiment 2 measures the volume displacement method of soil quality moisture content and the comparison of oven drying method

Device therefor sees embodiment 1.

Test uses 3 kinds of earth materials, respectively picks up from the black earth in Pekinese's silty loam, Jilin With the glutinous laterite in Jiangxi (being referred to as T1, T2, T3 individually below), to check this device to difference The measurement precision of soil.T1, T2, T3 are prefabricated into 5 kinds of design moisture content respectively: 10%, 15%、20%、25%、30%。

3 kinds of soil samples (T1, T2 and T3) of different designs moisture content are divided into 3 parts respectively Subsample, 3 one's share of expenses for a joint undertaking samples measure the volume displacement method of soil quality moisture content for the present invention Measure, dry under the conditions of 105 DEG C afterwards and measure with tradition oven drying method, be every kind of soil and exist In the case of different designs moisture content 3 times repeat experiment.

Measure the volume displacement method of soil quality moisture content, specifically comprise the following steps that

It is the constant-volume container of v' by soil sample to be measured loading volume, claims quality of soil sample m to be measured；To dress There is water filling in the constant-volume container of soil sample to be measured, cover liquid level locating cover, then lead to glue head dropper Cross water filling port to continue slowly dropwise to add water in constant-volume container, until having water droplet to occur at gap Time stop, now soil particle and water are full of constant-volume container, and soil sample reaches saturation state, inject Water the air being originally present in soil sample is all cemented out.Clean constant volume with blotting paper to hold On wall, residual is water stain, reading numerical values when electronic scale stable reading is constant, after weighing topped up with water In constant-volume container, soil sample is m ' with the gross mass of water；According to below equation calculating soil moisture content:

Formula 1:m_r=m'-m

Formula 2:v₀=v'-m_r/ρ_w

Formula 3: $v_s=\frac{m-{\mathrm{\ρ}}_w{v}_0}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}$

Formula 4: $v_w=\frac{{\mathrm{\ρ}}_s{v}_0-m}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}$

Formula 5: $\mathrm{\θ}=\frac{v_{\text{w}}{\mathrm{\ρ}}_w}{v_s{\mathrm{\ρ}}_s}\×100\%$

In formula, m_rThe quality of the water by being injected, unit g；v₀For soil particle volume with treat Survey soil sample aqueous volume sum, v_sFor soil particle volume, v_wFor soil sample water content to be measured Long-pending, unit cm³；ρ_wFor water density, ρ_sFor soil bulk density, unit g/cm³；θ is Soil quality moisture content, unit %.

Tradition oven drying method is measured as soil sample being placed in the baking oven of 105 DEG C, takes out after drying 72h Weigh, be calculated soil quality moisture content by tradition oven drying method.Drying plant be drying baker (in Outer joint Chongqing four reaches laboratory apparatus Co., Ltd, model: CS101-1E).

The result recorded by the method for the present invention (is dried with traditional geotechnological measuring method and claimed matter Amount method) result measured contrasts, and the accuracy that the inventive method is measured is described.In difference Under conditions of design moisture content, use the inventive method any soil sample to T1, T2 and T3 Being measured, the soil quality moisture content obtained and oven drying method (105 DEG C, 72h) are measured Result is advanced and is compared, and maximum absolute error is about 1%, as shown in table 1.

The absolute error (%) that table 1 volume displaced measurement soil quality moisture content compares with oven drying method measurement result

Being fitted by the moisture content that two kinds of methods record according to the following formula, the matched curve obtained is such as Shown in Fig. 4.

y=Ax

Wherein, the soil quality moisture content that y and x respectively instrument and tradition oven drying method record, %； A is regression coefficient, characterizes between the result that two kinds of measuring methods record degree one to one.

As seen from Figure 4, the coefficient of determination that 3 kinds of soil sample matchings obtain is all higher than 0.99, shows Have the most one by one between the result that any soil moisture content of this measurement device and oven drying method are measured Corresponding relation.Measured data shows, this instrument stable work in work, measurement result has higher Precision, and this apparatus measures process is simple, time saving and energy saving and saves the energy, can apply to Directly measuring of soil quality moisture content.

Measured data shows, the method measurement result of the present invention has degree of precision, can meet The requirement that outdoor field is measured immediately, process of measuring is simple, time saving and energy saving, save the energy, can To be applied to the direct measurement of any quality, free position Water Content Tests in Soil Samples.

The above is only the preferred embodiment of the present invention, it is noted that lead for this technology For the those of ordinary skill in territory, on the premise of without departing from the technology of the present invention principle, it is also possible to Making some improvements and modifications, these improvements and modifications also should be regarded as protection scope of the present invention.

Claims (7)

1. measure a volume displacement method for soil quality moisture content, specifically comprise the following steps that

Soil sample to be measured is loaded constant-volume container known to volume, claims quality of soil sample to be measured；To equipped with The constant-volume container of soil sample to be measured fills water, weighs after topped up with water soil sample and water in constant-volume container Gross mass；According to below equation calculating soil moisture content:

Formula 1:m_r=m'-m

Formula 2:v₀=v'-m_r/ρ_w

Formula 3: $v_s=\frac{m-{\mathrm{\ρ}}_w{v}_0}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}$

Formula 4: $v_w=\frac{{\mathrm{\ρ}}_s{v}_0-m}{{\mathrm{\ρ}}_s-{\mathrm{\ρ}}_w}$

Formula 5: $\mathrm{\θ}=\frac{v_w{\mathrm{\ρ}}_w}{v_s{\mathrm{\ρ}}_s}\×100\%$

In formula, m_rThe quality of the water by being injected, m is quality of soil sample to be measured, and m ' is topped up with water Soil sample and the gross mass of water in rear constant-volume container, unit g, v ' is constant-volume container volume, v₀For Soil particle volume and soil sample to be measured aqueous volume sum, v_sFor soil particle volume, v_wFor The aqueous volume of soil sample to be measured, unit cm³；ρ_wFor water density, ρ_sFor soil bulk density, Unit g/cm³；θ is soil quality moisture content, unit %；

Described constant-volume container is by a regular shape and on-deformable container and the liquid of upper end thereof Face locating cover composition, is provided with water filling port on liquid level locating cover, is provided with spilling water in vessel port Mouthful；Described gap is 45 ° to the angle of internal cutting；Water filling port lower port is a diameter of 2mm；The volume controlling in container by adding a cover liquid level locating cover in the upper end of container is perseverance Fixed, by water filling port slow liquid make-up in constant-volume container, gap exceeds for discharge The liquid of constant-volume container volume；

Described fill water, for the liquid level that adds water in constant-volume container close to constant-volume container mouth, cover Liquid level locating cover, is the most inwardly dripped to having water droplet to occur at gap by water filling port.

Method the most according to claim 1, it is characterised in that water density ρ_wValue 1.000g/cm³, soil bulk density ρ_sValue 2.653g/cm³。

3. equipment used by method described in any one of claim 1-2, it is characterised in that by Constant-volume container, weighing-appliance, water injection equipment form；Wherein constant-volume container is used for holding soil to be measured Sample, water injection equipment is for toward water filling in constant-volume container, and weighing-appliance is used for weighing quality.

4. the equipment described in claim 3, it is characterised in that described weighing-appliance is balance.

5. the equipment described in claim 4, it is characterised in that described weighing-appliance is electronics Balance.

6. the equipment described in claim 3, it is characterised in that described water injection equipment is dropper.

7. the application in measuring soil physical properties of the method described in any one of claim 1-2.