CN203083902U - Magnetic force suspension density tester - Google Patents

Abstract

The utility model discloses a magnetic force suspension density tester which is characterized by comprising two vertical polar permanent magnets of which the polarities are opposite to each other, wherein a hollow glass column is arranged between the two permanent magnets; and a transparent magnetic liquid for measuring the density of a sample is filled into the glass column. As the density is measured according to the height that the sample is suspended in the magnetic liquid, the magnetic force suspension density tester has the characteristics of simplicity in structure and convenience in operation, the density of the sample can be conveniently and rapidly tested or the content of one component in the sample is estimated and tested, an extreme small amount of the sample is needed, the range of substances which can be analyzed is wide, the tester is applicable to solid, liquids, adhesives, gels, paste and the like, and samples of irregular shapes can also be tested. The magnetic force suspension density tester solves the problems that the conventional density testing is large in expense, the operation is complex or the precision is not high and the like, is high in measurement precision, convenient and rapid to measure, low in expense and worthy of wide popularization.

Description

The magnetic levitation dasymeter

Technical field

The utility model relates to the dasymeter technical field, specifically is a kind of magnetic levitation dasymeter, is position that suspends in the magnetic levitation device by sample or the density of highly coming detection material.

Background technology

Current, though the instrument of a variety of measurement solids, fluid density and measurement solution concentration is arranged, as: density gradient column, the ball float hygrometer, the concussion tube densimeter, microactuator suspension resonator etc., but these detection techniques all have shortcoming and defect separately, as spend higher, complicated operation, precision not high, can only measure or the like specific sample.Density gradient column has high precision (10 ^-4G/cm ³), but the method cost is high, and complicated operation need be operated by the test man of professional training, could measure accurate data in the laboratory; Based on the modern comfort precision height of concussion Manifold technology, convenient and swift, but cost is very high, generally all wants several thousand yuan test fee, and can only detect the liquid of determining in the range of viscosities; The microactuator suspension resonator is the highest instrument of density measurement precision up to now, but this technology is only limited to analysis less than 3～15 microns material, and needs national state-of-the-art equipment and meticulous optical detection; So press for a kind of can be fast, accurately and spend the density that low checkout equipment or instrument are used to detect solid-liquid.

Summary of the invention

Technical problem to be solved in the utility model is to provide a kind of simple in structure, easy to operate magnetic levitation dasymeter at the above-mentioned state of the art, can conveniently detect the content of certain composition in the density of material or the estimation material, and cost is low, the measuring accuracy height, required sample size is few.

The utility model solves the problems of the technologies described above the technical scheme that is adopted: a kind of magnetic levitation dasymeter, it is characterized in that comprising two permanent magnets that polarity is oppositely arranged up and down, be provided with the glass column of a hollow between two permanent magnets, filling completely is used for the transparent magnetic liquid of measuring samples density in the glass column.

As improvement, the following end closure of described glass column, upper end open, the centre position, upper end of the permanent magnet of below is fixed in the lower end of glass column, the permanent magnet of top is nested with the upper end at glass column, and the two ends up and down of described glass column and the junction of two permanent magnets are respectively equipped with rubber band and seal.

As improvement, described permanent magnet is cube, and length is 2.5～3.5cm, and wide is 2.5～3.5cm, and height is 0.8～1.2cm, and the spacing of two permanent magnets is 4.5～5.5cm, and the length of described glass column is and the corresponding 4.5～5.5cm of the spacing of two permanent magnets.

Improve, described permanent magnet is long to be 3cm again, and wide is 3cm, and height is 1cm, and the spacing of two permanent magnets is 5cm, and the length of described glass column is and the corresponding 5cm of the spacing of two permanent magnets.

Further improve; the outside of described two permanent magnets is arranged with a shell that is used for support fixation; the front and back of two permanent magnets are provided with back up pad and fix in the enclosure; the position hollow out of correspondence and glass column in the middle of the described back up pad, the hollow out place is equipped with the clear glass that is used for the cover glass post respectively.

At last, described clear glass is marked with easy-to-read scale.

Compared with prior art, advantage of the present utility model is: the utility model is measured density by the height that sample is suspended in magnetic liquid, has simple in structure, convenience operation, can conveniently detect the content of certain composition in the density of material or the estimation material, required sample size is few, the material scope that can analyze is wide, applicable to solid, and liquid, colloid, gel, paste or the like can also be measured sample in irregular shape.The utility model measuring accuracy height (according to different experiment conditions can be as accurate as ± 0.02～± 0.0002g/cm3), measure convenient and swift and expense is cheap, be worth large-scale popularization.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is a surface structure synoptic diagram of the present utility model.

Embodiment

Embodiment describes in further detail the utility model below in conjunction with accompanying drawing.

As shown in the figure, a kind of magnetic levitation dasymeter, comprise up and down two permanent magnets 1 and 7, be arranged on the glass column 2 of a hollow between two permanent magnets 1 and 7, two permanent magnets 1 and 7 are the N utmost point, N is extremely relative, the perhaps S utmost point, the polarity that S is extremely relative is oppositely arranged, permanent magnet 1 and 7 is cube, long is 3cm, wide is 3cm, height is 1cm, and two permanent magnets 1 and 7 spacing are 5cm, and the length of glass column 2 is 5cm, the following end closure of glass column 2, upper end open, filling completely is used for the transparent magnetic liquid 4 of measuring samples density in the glass column 2, and the centre position, upper end of the permanent magnet 7 of below is fixed in the lower end of glass column 2, the permanent magnet 1 of top is nested with in the upper end of glass column 2, is respectively equipped with rubber band in the junction of the two ends up and down of glass column and two permanent magnets 1 and 7 and seals; Two permanent magnets 1 and 7 the outside are arranged with a shell 3 that is used for support fixation; shell 3 adopts plastics to make; being provided with back up pad 5 in the front and back of shell 3 interior two permanent magnets 1 and 7 fixes; the position hollow out of correspondence and glass column 2 in the middle of the back up pad 5; the hollow out place is equipped with the clear glass 6 that is used for cover glass post 2 respectively, is marked with easy-to-read scale at clear glass 6.

During use, open glass column 2 from top, sample is put into magnetic liquid 4, because magneticaction, sample can be suspended in the magnetic liquid 4, observes its high h from glass column 2 bottoms, then according to formula:

$h=\frac{({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_m)g{\mathrm{\μ}}_0{d}^2}{({\mathrm{\χ}}_s-{\mathrm{\χ}}_m)4{B_0}^2}+\frac{d}{2}---\left(1\right)$

Calculate ρ _s(being the density of sample):

${\mathrm{\ρ}}_s=\frac{{{4B}_0}^2(h-\frac{d}{2})({\mathrm{\χ}}_s-{\mathrm{\χ}}_m)}{g{\mathrm{\μ}}_0{d}^2}+{\mathrm{\ρ}}_m---\left(2\right)$

Wherein h is the height of sample in magnetic liquid, ρ _mBe the density of magnetic liquid, g is an acceleration of gravity, μ ₀Be permeability of vacuum, d is the distance between two magnets, B ₀Be the magnetic induction density of magnet surface, χ _sBe the magnetic susceptibility of sample, χ _mBe the magnetic susceptibility of magnetic liquid.

The concrete derivation of formula is:

Can derive to formula (1), the magnetic force that sample is subjected in magnetic liquid can be expressed as:

${\stackrel{\→}{F}}_{\mathrm{mag}}=\frac{({\mathrm{\χ}}_s-{\mathrm{\χ}}_m)}{{\mathrm{\μ}}_0}V(\stackrel{\→}{B}\·\stackrel{\→}{\▿})\stackrel{\→}{B}---\left(3\right)$

The earth to the acting force of sample is:

${\stackrel{\→}{F}}_g=({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_m)V\stackrel{\→}{g}---\left(4\right)$

When the sample stress balance:

${\stackrel{\→}{F}}_{\mathrm{mag}}+{\stackrel{\→}{F}}_g=({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_m)V\stackrel{\→}{g}+\frac{({\mathrm{\χ}}_s-{\mathrm{\χ}}_m)}{{\mathrm{\μ}}_0}V(\stackrel{\→}{B}\·\stackrel{\→}{\▿})\stackrel{\→}{B}=0---\left(5\right)$

$-({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_m)g+\frac{({\mathrm{\χ}}_s-{\mathrm{\χ}}_m)}{{\mathrm{\μ}}_0}(B_x\frac{\∂B_z}{\∂x}+B_y\frac{\∂B_z}{\∂y}+B_z\frac{\∂B_z}{\∂z})=0---\left(6\right)$

$\stackrel{\→}{B}\≡\left(\begin{array}{c}{B}_x\\ B_y\\ B_z\end{array}\right)=\left(\begin{array}{c}0\\ 0\\ -\frac{{2B}_0}{d}z+B_0\end{array}\right)---\left(7\right)$

Draw by formula (6) and formula (7) derivation:

$h=\frac{({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_m)g{\mathrm{\μ}}_0{d}^2}{({\mathrm{\χ}}_s-{\mathrm{\χ}}_m)4{B_0}^2}+\frac{d}{2}---\left(8\right)$

Claims (6)

1. magnetic levitation dasymeter is characterized in that comprising two permanent magnets that polarity is oppositely arranged up and down, is provided with the glass column of a hollow between two permanent magnets, and filling completely is used for the transparent magnetic liquid of measuring samples density in the glass column.

2. magnetic levitation dasymeter according to claim 1, the following end closure that it is characterized in that described glass column, upper end open, the centre position, upper end of the permanent magnet of below is fixed in the lower end of glass column, the permanent magnet of top is nested with the upper end at glass column, and the two ends up and down of described glass column and the junction of two permanent magnets are respectively equipped with rubber band and seal.

3. magnetic levitation dasymeter according to claim 1, it is characterized in that described permanent magnet is cube, length is 2.5～3.5cm, wide is 2.5～3.5cm, height is 0.8～1.2cm, the spacing of two permanent magnets is 4.5～5.5cm, and the length of described glass column is and the corresponding 4.5～5.5cm of the spacing of two permanent magnets.

4. magnetic levitation dasymeter according to claim 3 is characterized in that the long 3cm of being of described permanent magnet, and wide is 3cm, and height is 1cm, and the spacing of two permanent magnets is 5cm, and the length of described glass column is and the corresponding 5cm of the spacing of two permanent magnets.

5. according to the described magnetic levitation dasymeter of the arbitrary claim of claim 1 to 3; the outside that it is characterized in that described two permanent magnets is arranged with a shell that is used for support fixation; the front and back of two permanent magnets are provided with back up pad and fix in the enclosure; the position hollow out of correspondence and glass column in the middle of the described back up pad, the hollow out place is equipped with the clear glass that is used for the cover glass post respectively.

6. according to the described magnetic levitation dasymeter of the arbitrary claim of claim 1 to 3, it is characterized in that described clear glass is marked with easy-to-read scale.

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