CN103885078B - Sampled measurements topsoil precipitation rate of radon obtains the method and device of soil potentiality radon consistence - Google Patents

Abstract

A kind of sampled measurements topsoil precipitation rate of radon obtains the method and device of soil potentiality radon consistence, first with the soil of soil cutting device cutting naturalness, again soil cutting device is taken out from the soil of naturalness, unload the cutting ring adapter on soil cutting device, excise unnecessary soil, the soil at cutting ring internal ring two ends is repaired and scabbles.After having repaired, filter membrane is covered by taking one end that excellent cutting ring is connected with cutting ring adapter, cutting ring is together by a threaded connection with cutting ring adapter, the most again soil cutting device is connected with air pump and emanometer by pipeline and is combined into measurement apparatus, utilize measurement apparatus that the generation rate of radon in soil is measured, then by calculating acquisition soil potentiality radon consistence.

Description

Sampled measurements topsoil precipitation rate of radon obtain soil potentiality radon consistence method and Device

Technical field

The present invention relates to a kind of nuclear radiation detection technology, particularly a kind of sampled measurements topsoil precipitation rate of radon obtains The method and device of soil potentiality radon consistence.

Background technology

Maximum radon consistence potential in soil is exactly soil potentiality radon consistence, Soil-crop system and low-rise building Indoor Niton water Put down and hypogee radon level is closely bound up, the addressing of architectural engineering and the anti-radon design process of building are required for Soil Radon Concentration measures, and the soil of various different geological types will can be only achieved potentiality radon consistence water substantially in 2m even more depths Flat.But, fathoming of current Soil-crop system is general between 0.5-0.8m, and the Soil-crop system of this degree of depth is far below Soil potentiality radon consistence, and directly measuring soil potentiality radon consistence, the 2-3m that needs to burrow could directly measure, and difficulty is relatively Greatly.Accordingly, it would be desirable to a kind of method that topsoil sampled measurements is obtained soil potentiality radon consistence.

Summary of the invention

It is an object of the invention to overcome the above-mentioned deficiency of prior art to provide a kind of sampled measurements topsoil Radon eduction Rate obtains the method and device of soil potentiality radon consistence, uses the method can obtain quickly through simple computational methods Accurate soil potentiality radon consistence.

The technical scheme is that a kind of sampled measurements topsoil precipitation rate of radon obtains the side of soil potentiality radon consistence Method, it includes sampled measurements process and calculating process；

One, sampled measurements process:

Cutting ring on soil cutting device is together by a threaded connection with cutting ring adapter, then cutting ring is all pressed The soil of middle cutting naturalness of burying, makes the internal ring of cutting ring be full of soil, and keeps soil natural structure not to be destroyed, then will Cutting ring takes out from the soil of naturalness, unloads cutting ring adapter, and soil unnecessary on excision cutting ring, by cutting ring internal ring two ends Soil finishing scabble.

After having repaired, the one end being connected with cutting ring adapter taking excellent cutting ring is covered filter membrane, by cutting ring and ring Cutter adapter is together by a threaded connection, and is connected with air pump and emanometer by pipeline by cutting ring adapter and is combined into Measurement apparatus.

Opening air pump during measurement, air enters from the soil of cutting ring internal ring, enters emanometer by pipeline and discharges, by surveying radon The generation rate of cutting ring internal ring radon in soil is measured by instrument.

Two, process is calculated:

Under one-dimensional steady statue, only consider the diffusion of radon in uniform soil medium, and set up radon and transport in soil Move and the differential equation of distribution:

$D_e\frac{d^{2}C\left(x\right)}{{\mathrm{dx}}^2}-\mathrm{\λ}C\left(x\right)+\frac{A}{\mathrm{\η}}=0---\left(1\right)$

In formula, De is the effective diffusion cofficient of radon, and unit is m²·s^-1；C (x) is that in soil, the degree of depth is the radon consistence at x, Unit is Bq m^-3；X is depth of soil, and unit is m；λ is the decay constant of radon, and its value is 2.1 × 10^-6s^-1；η is soil hole Porosity, dimensionless, the corresponding different porosity η of different soil types, obtain according to the type of soil approximation of tabling look-up, or will Soil in cutting ring is taken back laboratory and is accurately measured and obtain；A is the generation rate of radon in soil, and unit is Bq m^-3·s^-1。

Owing to soil surface radon in air concentration is the lowest, it is possible to being approximately considered is 0, boundary condition: C |_X=0=0；Soil is infinite Depths, Soil-crop system still can not be infinitely great, boundary condition: C |_X=∞Bounded.

Solve and bring into boundary condition to formula (1) to obtain:

$C\left(x\right)=\frac{(1-e^{-x\sqrt{\frac{\mathrm{\λ}}{D_e}}})}{\mathrm{\λ}}\frac{A}{\mathrm{\η}}---\left(2\right)$

Soil potentiality radon is it can be seen that be the radon consistence in the infinite depths of soil, it may be assumed that

$C\left(\mathrm{\∞}\right)=\frac{A}{\mathrm{\λ}\mathrm{\η}}---\left(3\right)$

Utilizing measurement apparatus to measure the generation rate of radon in soil, the reading C of stable rear emanometer is:

C=AV/F (4)

F is the flow rate of pump；V is the volume of sampling soil, and unit is m³；

Relevant parameter is substituted into formula (4) and just can obtain the value of A.

Again the value of A, η is substituted into formula (3) and just can obtain the potentiality radon consistence of soil.

Above-mentioned measuring method use measurement apparatus connected by pipeline by soil cutting device, air pump and emanometer after group Becoming, the straight tube handle steam vent on soil cutting device is connected with one end of air pump by pipeline, and the other end of air pump is by pipe Road is connected with emanometer.

Described soil cutting device is made up of cutting ring adapter and cutting ring.One end of described cutting ring adapter is provided with ring Shape atrium, the port in annular opening chamber is provided with stepped hole, and the port of stepped hole is provided with the female thread being connected with cutting ring, and annular is opened The bottom centre in oral cavity is provided with centre bore, and the other end of cutting ring adapter is welded with a straight pipe communicated with centre bore, directly The other end of siphunculus is welded with an one end and closes the straight tube handle of one end open, the steam vent on straight tube handle and straight pipe Endoporus communicates.One end of described cutting ring is provided with the edge of a knife, and the other end of cutting ring is provided with the external screw thread being connected with cutting ring adapter.

The effect arranging annular opening chamber on cutting ring adapter is so that air-flow can be uniformly through soil, by soil Radon by air-flow homogeneous band out, improves the accuracy measured.

The present invention compared with prior art has a characteristic that

The method using the present invention to provide can utilize topsoil precipitation rate of radon to obtain soil potentiality radon consistence, and it is adopted Process measured by sample and computational methods are simple, and is obtained in that accurate soil potentiality radon consistence.

Below in conjunction with the drawings and specific embodiments, the invention will be further described.

Accompanying drawing explanation

The measurement system schematic that accompanying drawing 1 provides for the present invention, in figure, P1 is airintake direction, and P2 is outgassing direction；

Accompanying drawing 2 is the structural representation of measurement apparatus；

Accompanying drawing 3 is the A-A sectional view in accompanying drawing 2；

Accompanying drawing 4 is the structural representation of cutting ring adapter；

Accompanying drawing 5 is the B-B sectional view in accompanying drawing 4；

Accompanying drawing 6 is the structural representation of cutting ring；

Accompanying drawing 7 is the C-C sectional view in accompanying drawing 6.

Detailed description of the invention

A kind of sampled measurements topsoil precipitation rate of radon obtains the method for soil potentiality radon consistence, and it includes sampled measurements mistake Journey and the process of calculating；

One, sampled measurements process:

Cutting ring 1-2 on soil cutting device 1 is together by a threaded connection, then by ring with cutting ring adapter 1-1 Cutter 1-2 is all pressed in soil the soil cutting naturalness, makes the internal ring of cutting ring 1-2 be full of soil 4, and keeps soil 4 natural Structure is not destroyed, then is taken out from the soil of naturalness by cutting ring 1-2, unloads cutting ring adapter, many on excision cutting ring 1-2 Remaining soil, repairs the soil 4 at cutting ring 1-2 internal ring two ends and scabbles.

After having repaired, the one end being connected with cutting ring adapter taking excellent cutting ring 1-2 is covered filter membrane 5, by cutting ring 1-2 is together by a threaded connection with cutting ring adapter 1-1, the most again by soil cutting device 1 by pipeline and air pump 2 and survey Radon instrument 3 connection is combined into measurement apparatus.

Opening air pump 2 during measurement, air enters from the soil 4 of cutting ring 1-2 internal ring, enters emanometer 3 by pipeline and discharges, By emanometer 3, the generation rate of radon in cutting ring 1-2 internal ring soil 4 is measured

Two, process is calculated:

Under one-dimensional steady statue, only consider the diffusion of radon in uniform soil medium, and set up radon and transport in soil Move and the differential equation of distribution:

$D_e\frac{d^{2}C\left(x\right)}{{\mathrm{dx}}^2}-\mathrm{\λ}C\left(x\right)+\frac{A}{\mathrm{\η}}=0---\left(1\right)$

In formula, De is the effective diffusion cofficient of radon, and unit is m²·s^-1；C (x) is that in soil, the degree of depth is the radon consistence at x, Unit is Bq m^-3；X is depth of soil, and unit is m；λ is the decay constant of radon, and its value is 2.1 × 10^-6s^-1；η is soil hole Porosity, dimensionless, the corresponding different porosity η of different soil types, obtain according to the type of soil approximation of tabling look-up, or will Soil 4 in cutting ring 1-2 is taken back laboratory and is accurately measured and obtain；A is the generation rate of radon in soil, and unit is Bq m^-3·s^-1。

Owing to soil surface radon in air concentration is the lowest, it is possible to being approximately considered is 0, boundary condition: C |_X=0=0；Soil is infinite Depths, Soil-crop system still can not be infinitely great, boundary condition: C |_X=∞Bounded.

Solve and bring into boundary condition to formula (1) to obtain:

$C\left(x\right)=\frac{(1-e^{-x\sqrt{\frac{\mathrm{\λ}}{D_e}}})}{\mathrm{\λ}}\frac{A}{\mathrm{\η}}---\left(2\right)$

Soil potentiality radon is it can be seen that be the radon consistence in the infinite depths of soil, it may be assumed that

$C\left(\mathrm{\∞}\right)=\frac{A}{\mathrm{\λ}\mathrm{\η}}---\left(3\right)$

Utilizing measurement apparatus to measure the generation rate of radon in soil 4, the reading C of stable rear emanometer 3 is:

C=AV/F (4)

F is the flow rate of pump；V is the volume of sampling soil, and unit is m³；

Relevant parameter is substituted into formula (4) and just can obtain the value of A.

Again the value of A, η is substituted into formula (3) and just can obtain the potentiality radon consistence of soil.

The measurement apparatus that above-mentioned measuring method uses is connected by pipeline by soil cutting device 1, air pump 2 and emanometer 3 Rear composition, the straight tube handle 1-1-6 steam vent on soil cutting device 1 is connected with one end of air pump 2 by pipeline, air pump 2 The other end is connected with emanometer 3 by pipeline.

Described soil cutting device 1 is made up of cutting ring adapter 1-1 and cutting ring 1-2.Described cutting ring adapter 1-1's One end is provided with annular opening chamber 1-1-1, and the port of annular opening chamber 1-1-1 is provided with stepped hole 1-1-2, the end of stepped hole 1-1-2 Mouth is provided with the female thread 1-1-3 being connected with cutting ring 1-2, and the bottom centre of annular opening chamber 1-1-1 is provided with centre bore 1-1-4, ring The other end of cutter adapter 1-1 is welded with a straight pipe 1-1-5 communicated with centre bore 1-1-4, another of straight pipe 1-1-5 End is welded with an one end and closes the straight tube handle 1-1-6 of one end open, the steam vent on straight tube handle 1-1-6 and straight pipe 1- The endoporus of 1-5 communicates.One end of described cutting ring 1-2 is provided with edge of a knife 1-2-1, and the other end of cutting ring 1-2 is provided with and is connected with cutting ring The external screw thread 1-2-2 that device 1-1 connects.

Cutting ring adapter 1-1 is arranged the effect of annular opening chamber 1-1-1 be so that air-flow can uniformly through soil 4, By the radon in soil 4 by air-flow homogeneous band out, the accuracy measured is improved.

Claims (1)

1. the method that sampled measurements topsoil precipitation rate of radon obtains soil potentiality radon consistence, is characterized in that: it includes adopting Sample measures process and the process of calculating；

One, sampled measurements process:

Cutting ring on soil cutting device is together by a threaded connection with cutting ring adapter, then cutting ring is all pressed into soil The soil of middle cutting naturalness, makes the internal ring of cutting ring be full of soil, and keeps soil natural structure not to be destroyed, then by cutting ring Taking out from the soil of naturalness, unload cutting ring adapter, soil unnecessary on excision cutting ring, by the soil at cutting ring internal ring two ends Earth finishing is scabbled；

After having repaired, the one end being connected with cutting ring adapter taking excellent cutting ring is covered filter membrane, by cutting ring with cutting ring even Connect device to be together by a threaded connection, soil cutting device is connected with air pump and emanometer by pipeline is combined into survey the most again Amount device；

Opening air pump during measurement, air enters from the soil of cutting ring internal ring, enters emanometer by pipeline and discharges, by emanometer pair The generation rate of cutting ring internal ring radon in soil measures；

Two, process is calculated:

Under one-dimensional steady statue, only consider the diffusion of radon in uniform soil medium, and set up radon migrate in soil and The differential equation of distribution:

$D_e\frac{d^{2}C\left(x\right)}{{\mathrm{dx}}^2}-\mathrm{\λ}C\left(x\right)+\frac{A}{\mathrm{\η}}=0---\left(1\right)$

In formula, De is the effective diffusion cofficient of radon, and unit is m²·s^-1；C (x) is that in soil, the degree of depth is the radon consistence at x, unit For Bq m^-3；X is depth of soil, and unit is m；λ is the decay constant of radon, and its value is 2.1 × 10^-6s^-1；η is soil porosity, Dimensionless, the corresponding different porosity η of different soil types, obtain according to the type of soil approximation of tabling look-up, or by cutting ring In soil take back laboratory and accurately measure and obtain；A is the generation rate of radon in soil, and unit is Bq m^-3·s^-1；

Owing to soil surface radon in air concentration is the lowest, it is possible to being approximately considered is 0, boundary condition: C |_X=0=0；The infinite depths of soil, Soil-crop system still can not be infinitely great, boundary condition: C |_X=∞Bounded；

Solve and bring into boundary condition to formula (1) to obtain:

$C\left(x\right)=\frac{(1-e^{-x\sqrt{\frac{\mathrm{\λ}}{D_e}}})}{\mathrm{\λ}}\frac{A}{\mathrm{\η}}---\left(2\right)$

Soil potentiality radon is it can be seen that be the radon consistence in the infinite depths of soil, it may be assumed that

$C\left(\mathrm{\∞}\right)=\frac{A}{\mathrm{\λ}\mathrm{\η}}---\left(3\right)$

Utilizing measurement apparatus to measure the generation rate of radon in soil, the reading C of stable rear emanometer is:

C=AV/F (4)

F is the flow rate of pump；V is the volume of sampling soil, and unit is m³；

Relevant parameter is substituted into formula (4) and just can obtain the value of A；

Again the value of A, η is substituted into formula (3) and just can obtain the potentiality radon consistence of soil；

Described measurement apparatus is formed after being connected by pipeline by soil cutting device, air pump and emanometer, soil cutting device On straight tube handle steam vent be connected with one end of air pump by pipeline, the other end of air pump passes through pipeline and is connected with emanometer；

Described soil cutting device is made up of cutting ring adapter and cutting ring；One end of described cutting ring adapter is provided with annular and opens Oral cavity, the port in annular opening chamber is provided with stepped hole, and the port of stepped hole is provided with the female thread being connected with cutting ring, annular opening chamber Bottom centre be provided with centre bore, the other end of cutting ring adapter is welded with a straight pipe communicated with centre bore, straight pipe The other end be welded with one end and close the straight tube handle of one end open, the endoporus of the steam vent on straight tube handle and straight pipe Communicate；One end of described cutting ring is provided with the edge of a knife, and the other end of cutting ring is provided with the external screw thread being connected with cutting ring adapter.