SU1204019A1 - Device for measuring density - Google Patents

Description

The invention relates to a device for measuring the density and is intended to measure the density of materials with variable elemental composition, such as fiberglass.

The purpose of the invention is the extension of functionality to materials with a rough surface and with variable elemental composition. ; The invention is illustrated in the drawing, which shows a diagram of the device.

The device contains a source of 1 soft X-ray radiation, placed in a protective housing 2, first 3, second 4 and third 5 detectors, calculating unit 6, multiplication unit 7. The detectors are equipped with collimators 8, 9 and 10, and source 1 is a collimator 11. Output multiplier 7 is connected to the recording device 12.

The device works as follows. Case 2 is installed close to the controlled material. Radiation from source 1 through the collimator 11 falls on the controlled material. The radiation scattered in it is recorded by the first 3, second 4 and third 5 detectors.

Collimator 8 of the first detector 3; oriented at an angle ft relative to; But the axis of the collimator 11. The signal recorded by the first detector 3 is electrically

Kd6 ,,. . - -. .

u, (uf, ci2 i-uhl

 +

.-i- I C05B

J) ()

 where k is a coefficient taking into account the intensity of the radiation source and the conversion of the radiation into an electrical signal; b - scattering coefficient, not dependent on the composition for materials with a low atomic number; S, is the area of the first detector; registration efficiency first

.-p detector; - distance

from the first detector 3 to the center of the scattering volume, limited by the visibility area of the collimators 8

and 11; (1 (is the absorption coefficient of the incident radiation controlled by

material; p is the density of the controlled material; I, is the length of the first collimator; and 2, -. The distance between the outlet openings of the collimators 8 and 1 1; - the depth of the bumps.

The collimator 9 of the second detector 4 is also oriented under ft relative to the axis of the collimator 11 and the electrical signal recorded by the second detector 4

(J, -.

,; pp (be, ctg, e-, b) (, (2)

.-four

 II C05 A)

WHERE S is the area of the second detector; 2 efficiencies of the registration of a second vto detector; , t distance i S in / 3

from the second detector 4 to the center of the scattering volume, bounded by the visibility area of collimators 9 and 11; 2, the length of the second collimator 4.12 — the distance between the outlet openings of the collimators 9 and 11,

The field of view of the third detector 5 is practically unlimited by the collimator 10 and all radiation scattered in its direction enters the third detector. As the calculations are shown, recorded by the third detector 3 electrical signal

U.

(3)

R, | uln

cos

where S. is the area of the third detector; IJ is the detection efficiency of the third detector; R.j is the distance from the third detector to the center of the scattering volume located, taking into account the small radiation penetrating power and small roughness values h, near the end of the collimator 10; J) is the length of the collimator 10. The electrical signals of the detector 3 and 4 are fed to the calculator 6,

in which the signal tl Rl5 ,, is defined

u (En77 en - :; T7 + Pp (se, -ue,) ctgJu and.

(four)

, G V g i l I I - 1 I t

r «, V coefi which, as follows from relation (4), does not depend on uh,. against surface roughness.

The parameters of the detectors 3, 4, collimators 8, 9 and the measurement geometry are selected in such a way that equality

(five)

iE, g

 sfvi j

where the first term in the right side of expression (4) is zero.

In the multiplication unit, a signal is generated.

(5h,

(iej-Ae,) ctj | j

which is not affected by the composition of the controlled material. Sig12040194

The oil is transferred to the recording device 12, where it is fixed at the required scale in accordance with the ratio

5. ,, p, 1 “. P kd5 ,, (iE, -AE, ci3P U,

Editor V. Ivanova

Compiled by And, Pavlenko

TehredI.Popovich Proofreader E, Sirokhman

Order 5267/2 Circulation 778 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (1)

DEVICE FOR MEASURING DENSITY, comprising a housing, a collimated source placed in it, and. two collimated detectors, a unit for calculating the logarithm of the signal ratio of the first and second detectors, the inputs of which are connected to the detectors, and a recording device, characterized in that, in order to expand the functionality of materials with a rough surface and variable elemental composition, the device additionally contains a third detector ^A - to a recording device, wherein the axis of the source collimator is perpendicular to the plane of the body in contact with the material being controlled, the axis of the collimators of the first and second detectors are located at an angle p relative to the axis of the source collimator, the following ratio being true, where 1,, 1 ₂ are the lengths of the collimators first and second detectors; ΔΪ ₍ , Λί ₂ - the distance between the source collimator and the collimator of the first and second detectors in the specified plane §; S ,, S ₂ - the area of the first and second detectors; ξ ,, ~ registration efficiency of the first and second detectors; and the density is determined from the following relation: ¹⁴ about U j where K is a coefficient taking into account the intensity of the radiation source and the conversion of radiation into an electrical signal; (j is the scattering coefficient; S, j, ξ ₃ is the area and registration efficiency of the third detector; - distance from the third detector to the point of intersection of the axis of the collimator of the source with the specified plane; UijU ^ hU-j - signals of the first, second and third detectors.