SU1204020A1 - 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 to expand the functionality of materials with variable elemental composition.

The invention is illustrated in the drawing, which shows a diagram of the device.

The device contains a source of soft X-ray radiation placed in a protective housing 2, the first detector 3, the second detector computing unit 5, multiplication unit 6 The detectors are equipped with collimators 7 and 8, and the source 1 is connected with a collimator 9. Multiplication unit b is connected to a recording device 10

The device works as follows.

The housing 2 is installed close to the controlled material. The radiation from the source 1 through the collimator 9 falls on the controlled material. The radiation scattered in it is recorded by the first 3 and second 4 detectors. The collimator 7 of the first detector 3 is oriented at an angle relative to the axis of the collimator 9, the electrical signal detected by the first detector 3

I, ,, -pp, ectap / i, -l-I and -,. G II 31 I

 H-J-1

 V CDSpl

where K is a coefficient taking into account the intensity of the radiation source and conversion of the radiation into an electrical signal, (j is the scattering coefficient independent of the composition for materials with low atomic number; S, sf, is the area and recording efficiency of the first detectors (1 )

Torah; R, 2 +

h-

sinp

- distance

from the first detector to the center of the scattering volume, limited to the field of visibility of the collimators 7 and 9; (- the length of the collimator of the first detector; & E - the distance between the outlet openings of the collimators 7 and 9; W is the absorption coefficient of the incident radiation of the material being monitored; p is the density of the material being monitored.

The field of view of the second detector 4 is practically unlimited by the collimator 8, and all the radiation scattered in its direction enters the second detector 4. As shown by the calculations recorded by the second detector 4 electrical signal

KY5 ,,

1.COS

(2)

where S ,,, 2 area and the registration efficiency of the second detector; R is the distance from the second detector to the center of the {scattering volume, located in this case at a negligible distance from the surface. bones of controlled material; 1 - the length of the collimator 8.

The electrical signals of the detectors 3 and 4 are fed to a calculation block 5, in which the signal

thirty

0

The parameters of the detectors and the measurement geometry are selected in such a way that the equality

 (s .-. ,, eb ,,, W

where the first term in the right side of expression (3) is zero.

In the unit, the sheaves produce a signal

U4-UvlJ,

KJ5

five

R

2 l 1.,

rde: HDR

(five)

&

which is not affected by the composition of the material being monitored. The signal is transmitted to the recording device 10, where it is recorded at the required scale in accordance with the ratio

P cj

Sj.Aectqfl

dj

her

s

(6)

Claims (1)

DEVICE FOR MEASURING DENSITY, comprising a housing, a collimated source placed in it, and two detectors, the first of which is located in the collimator, a unit for calculating the logarithm of the signal ratio of the second and first detectors, the inputs of which are connected to the detectors, and a recording device, characterized in that, , in order to expand the functionality to materials with variable composition, the device further comprises a multiplication unit, the first input of which is connected to, the output of the unit for calculating the logarithm of the ratio s of the detectors, the second to the second detector, and the output to the recording device, the axis of the source collimator being perpendicular to the plane of the body in contact with the material being controlled, the axis of the first receiver's collimator located at an angle β relative to the axis of the source collimator, and the following relation is true: where I ,, is the distance from the detectors ^ to the indicated plane of the housing; d £ the distance between the collimators of the source and the first detector in the indicated plane of the housing; S ₄ , S _{2 the} area of the first and second detector - the efficiency of registration of the first and second detectors, and the density is determined from the following ratio: e / .. (where K is the coefficient taking into account the intensity of the radiation source and the conversion of radiation into an electrical signal, o is the distance coefficient; U ,, and ₂ are the signals of the first and second detectors. second detector th detector; & B is the distance between the outlet openings of the collimators 7 and’9; p is the absorption coefficient of the incident radiation of the controlled material; p is the density of the controlled material. The scope of the second detector 4 is practically unlimited by the collimator 8, and all the radiation scattered in its direction enters the second detector 4. As the calculations showed, the second signal recorded by the second detector 4 4, multiplication block 6. A - 7 ’(2)