GB2191285A

GB2191285A - Stabilizing the measuring geometry in an analyzer

Info

Publication number: GB2191285A
Application number: GB08712549A
Authority: GB
Inventors: Markku Juhani Rintamaki
Original assignee: Outokumpu Oyj
Current assignee: Outokumpu Oyj
Priority date: 1986-06-02
Filing date: 1987-05-28
Publication date: 1987-12-09
Also published as: GB8712549D0; DE3718230A1; FI862344A0; FI862344A; FI77942B; FI77942C

Description

GB2191285A 1 SPECIFICATION ber, against the controls installed in the mea

suring member of the analyzer. Now the film Apparatus for stabilizing the measuring of the measuring cell is advantageously geometry in an analyzer pressed against the protruding plate serving as 70 the sample surface and provided with an aper The present invention relates to an apparatus ture, and the sample surface is further pressed for stabilizing the measuring geometry, and inside the measuring cell so that the extra particularly the sample surface in an x-ray ana- tightening according to the invention is simul lyzer when the measurment is carriedout taneously provided for the film and that the through a thin film stretched over an aperture 75 measuring geometry is maintained stabile. By provided in the measuring cell. means of the stabile measuring geometry, it is In tube-activated x-ray analyzers, the stabil- also possible to standardize the distance of ity of the measuring geometry is a factor the film of the measuring cuvette. Moreover, which essentially affects the measuring accu- by employing the apparatus of the present in racy and the reproducibility of the measure- 80 vention, it is possible to delimit on the film a ments. In process analyzers, where the sam- surface area corresponding to the specific ple under examination flows in a measuring measuring demands in question.

cell and the measurement is carried out In the following the invention is explained through a thin film, it is necessary to attach with reference to the appended drawing, the cell so that the operator can easily change 85 where the film of the cell as part of the routine pro- Figure 1 is an illustration of a preferred em cedure. It is likewise necessary to replace the bodiment of the invention as applied to the cell with a new one every once in a while due measuring device of an analyzer, seen in par to wearing. This requires that the cell is easy tial side-view elevation; to detach and to turn into sight for mainte- 90 Figure 2 is an illustration of another pre nance. When the cell is again installed in the ferred embodiment of the invention as applied measuring geometry, it is required that the to the measuring device of an analyzer, again film is set at exactly the same distance as seen in partial side-view elevation; and before in order to keep the measuring geo- Figures 3 and 4 illustrate the advantageous metry unchanged. Particularly in x-ray diffrac- 95 form of the standard sample surface of the tion geometry, the changes in the distance of apparatus with respect to various types of ra- the film have a considerable influence in the diation.

location of the diffraction line. According to Fig. 1, in the cover 2 provided The main reasons for the fact that the cell in the measuring head 1 of the analyzer there film is not always set at a standard distance 100 is located the cell 3 where the material to be are: changes in the pressure of the cell flow analyzed enters via the inlet pipe 4 and wher and wearing of the equipment, as well as dif- efrom the material is discharged via the outlet ferent tolerances. The infiluence of the prespipe 5. The sample entering from the inlet sure changes can be reduced by stretching pipe 4 is measured through the thin film 6 the cuvette film more tightly and by limiting 105 stretched over the opening 10 located in the the surface area so that it corresponds to the cell 3. In order and achieve the stabilization of measuring geometry in question. The disturthe measuring geometry according to the in bance caused by mechanical wearing is elimi- vention, the measuring head 1 is provided nated by constructing at the measuring end of with a protruding plate 7, and the measuring the analyzer a stationary surface which defines 110 takes place through the aperture 11 of the the distance of the sample. said plate. While closing the cover 2, the cell It has, however, been observed that the which is attached in an essentially flexible prior art arrangements have many drawbacks manner to the inlet and outlet pipes 4 and 5, for instance as regards the tightness of the is pressed by aid of the spring 8 against the film, in which case the used pre-tightening is 115 stoppers 9 located in the measuring head 1 not sufficient for maintaining the measuring and serving as controls. Now the film 6 of the geometry of the analyzer in the desired degree cell is advantageously pressed against the pro of stability. truding plate 7 provided with an aperture, The purpose of the present invention is to which is required in the measuring geometry.

achieve an improved and more secure appara- 120 The protruding plate 7, the outer surface tus for stabilizing the measuring geometry in whereof is essentially of the same shape as an x-ray analyzer by providing the film of the the opening of the cell 6, is further partially measuring cell with an extra tightening and by pressed inside the cell 3, which provides an stadardizing the distance of the film within the extra tightening for the film 6.

measuring geometry. The essential novel fea- 125 In the embodiment of Fig. 2, in order to tures of the invention are enlisted in the ap- achieve the measuring geometry of the inven pended patent claim 1. tion, the clamp ring 14 of the cell film 13 is According to the invention, in order to pro- provided with a protruding plate 15, and the vide extra tightening for the film, the cell is measurement is carried out through the aperpressed, by aid of a mechanical power mem- 130 ture provided in the said plate. In order to 2 GB2191285A 2 perform the measurements in an advantageous ray analyzer.

manner through the opening 20 of the cell, 7. Apparatus according to claim 6, wherein the cell 16 is pressed by aid of the spring 17 the aperture provided in the protruding plate is against the film 13 and against the protruding essentially a circle for measuring the X-ray plate 15 located in the film clamp ring 14, 70 fluorescence radiation.

and further against the measuring head 18. 8. Apparatus for stabilizing the measuring Owing to the advantageous shape of the stop- geometry in an analyzer, substantially as here pers 19 located in the film clamp ring 19, the inbefore described with reference tothe ac film 13 of the cell is advantageously pressed companying drawings.

against the clamp ring 14. At the protruding plate 15, the clamp ring 14 is further pressed Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd, Dd 8991685, 1987.

into the cell 16 and thus it provides an advan- Published at The Patent Office. 25 Southampton Buildings, tageous extra tightening for the cell film 13. London, WC2A l AY, from which copies may be obtained.

The aperture provided in the protruding plate 7 or 15 forms, according to the invention, the standard sample surface of the x-ray analyzer. While employing the preferred embodiment of Fig. 2, where the protruding plate 15 serving as the standard sample surface is located in the film clamp ring 14, the standard sample surface can easily be changed into another type when desired. Figs. 3 and 4 illustrate the advantageous forms for the standard sample surface in an analyzer measuring both x-ray fluorescence radiation and x-ray diffraction radiation, according to the preferred embodiment of Fig. 1. From Fig. 3 it is seen that for x-ray fluorescence radiation, the standard sample surface is advantageously a circle 11. According to Fig. 4, the standard sample surface for x-ray diffraction radiation is represented as an ellipse 12 placed in the measuring direction. However, the standard sample surface for x-ray diffraction radiation can ad- vantageously be for instance a rectangle placed in the measuring direction.

Claims

1. Apparatus for stabilizing the measuring geometry in an analyzer when a thin film stretched over the opening provided in the measuring cell is employed in the measuring operation, wherein in the measuring device of the analyzer there is installed a protruding plate provided with an aperture so that said protruding plate, by means of the power member and the controls of the measuring device, tightens the film of the measuring cell.

2. Apparatus according to claim 1, wherein the protruding plate is fitted at the measuring head of the analyzer.

3. Apparatus according to claim 1, wherein the protruding plate is fitted within the clamp ring of the cell film.

4. Apparatus according to any one of the preceding claims, wherein the outer surface of the protruding plate essentially conforms to the shape of the opening in the measuring cell.

5. Apparatus according to any one of the preceding claims, wherein the analyzer is an X-ray analyzer.

6. Apparatus according to claim 5, wherein the aperture provided in the protruding plate forms the standard sample surface of the X-