GB1162173A - Improvements in or relating to X-Ray Analysis - Google Patents

Abstract

1,162,173. X-ray fluorescence analysis. UBE KOSAN K.K. Sept.29, 1966, No.43677/66. Heading G1A. [Also in Divisions H1 and H5] In X-ray analysis apparatus the sample is excited by alpha rays and electromagnetic radiation from a radio-active source and the characteristic X-rays emitted by light and heavy elements of the sample are detected by a proportional counter connected to a pre-amplifier, a linear amplifier, a pulse height analyzer and a scaler. Radiation from the sources 5, 6, Fig. 1, falls on the sample 4 to generate characteristic X-rays which are detected by the proportional counters 7, 9. Counter 9 has a window with a filter 8 which filters out radiation which overlaps a peak of an element to be detected. The material of the filter is the same as the element to be detected e.g. to determine Al 2 O 3 in a cement mix also containing SiO 2 , the Si K radiation is eliminated by an Al filter. A plurality of filtered cells may be used, or a single cell with provision for interchangable filters. The outputs of the counters are fed to pulse height analyzers set to detect the required component elements of the test sample. Light elements are excited by alpha radiation from the Po210 source 5 and heavy elements by electromagnetic radiation from the source 6 e.g. H 3 absorbed on Ti, Ni or Zr. A single substance e.g. Am241 may be used to provide both radiations. The following determinations may be made:- Cement raw materials may be tested for Al 2 O 3 ; SiO 2 ; CaO and Fe 2 O 3 using an Al filter. Cement or cement clinker may be tested for Al 2 O 3 ; SiO 2 ; SO 3 ; CaO and Fe 2 O 3 using Al, Si and S filters. Iron ore may be tested for MgO; Al 2 O 3 ; SiO 2 ; CaO; MnO; Fe 2 O 3 ; and TiO 2 using Mg. Al Si, Mn, Ti and Fe filters. Glass may be tested for Na 2 O; MgO; Al 2 O 3 ; SiO 2 ; SO 3 ; CaO; Fe 2 O 3 B 2 O 3 ; BaO and PbO using Na, Mg, Al, Si, S and Ca filters. Magnesium clinker may be tested for MgO; Al 2 O 3 ; P; S; CaO and Fe 2 O 3 using Mg, Al and Si filters. Petroleum may be tested for S without using filters. Iron Slag may be tested for MgO; Al 2 O 3 ; SiO 2 SO 3 ; CaO and Fe 2 O 3 using Mg, Al, Si and S filters. Steel may be tested for C; Si; P; S; Mn and Cr using P, Si and Cr filters. Pig Iron may be tested for C; Si; P; S; Mn and Cu using a Si filter. Sample transferring mechanism The measuring chamber 62, (Fig.4), which is evacuated to reduce radiation attenuation is attached to a sample exchange chamber 52 and extending between the chambers is a sample carrier 68 with two sample stations 50, 51. While a measurement is being made on the sample at 50, a lever 53 may be operated to raise a member 67 which squeezes the sealing rings to isolate the chamber 62 from the vacuum in chamber 62. Air is then introduced into chamber 52 from valve 56 so that the lid 55 may be removed and sample 51 changed. Chamber 52 is then evacuated through valve 56 and lever 53 released. When the measurement is finished the sample 50 may be replaced by the new sample 51 by rotating the knob 69. In a simpler embodiment, Fig.3 (not shown), chamber 52 is not used and the rotatable sample carrier 68 is replaced by a carrier which slides linearly between a plurality of sealing rings. When in the test position the sample may be rotated to eliminate effects due to surface irregularities.