Patent GB-919384-A (GB)
Title: Improvements in or relating to calculators
Inventor: SERMIN DENNIS FRANCIS
IPC: G06G1/00
Filed: 1960-10-31
Abstract: 919,384. Calculating apparatus. BRITISH IRON & STEEL RESEARCH ASSOCIATION, and APPLIED RESEARCH LABORATORIES (GREAT BRITAIN) Ltd. Jan. 26, 1962 [Oct. 31, 1960], No. 37301/60. Class 106 (1). The device calculates the X-ray mass absorbtion coefficients Á/p of a first set of elements at the wavelengths of X-ray emission lines of elements of a second set (Á=X-ray linear absorbtion coefficient; p=density of element). The elements of the first set particularly described are the series Neon to Bismuth and the elements of the second set are the series Sodium to Bismuth, although it is stated that the sets may be extended. The emission lines are the first two K lines and the first three L lines. The calculator may also be used to predict qualitatively enhancement phenomena. The described calculator is circular, although it is stated that it may be linear, and comprises three relatively rotatable discs. The top disc 1 carries scales 8, 9 marked with values proportional to the X-ray mass coefficients concerned and which meet at the line 10. The intermediate disc 2 carries an outer name scale 13 on which the names of the elements of the first set are marked at angular distances proportional to the logarithms of the wavelengths of the K absorbtion edges of the elements, two scale factor scales which appear at windows 28, 29 of disc 1, and five scales carrying the names of the elements of the second set which appear at a labelled window 16 of disc 1 which distinguishes the elements on each scale. The lower disc 3 carries on an arcuate extension a scale 35 and has a window 33 (Fig. 2) at which appear elements of the second set marked on the reverse side of disc 2 which also carries a name scale 50 calibrated in similar manner to the scale 13. The three scales correspond to the cases in which the K and L edges of an element lie both to the right, or to the left, or one on each side, of the wavelength of the X-ray emission line at which the mass absorption coefficient is to be calculated. This is explained in the Specification with reference to Figs. 8 and 9 (not shown). To calculate the mass absorption coefficient of an element at the wavelength of the first K emission wavelength of, say, Argon, the disc 2 is rotated until the symbol A (Argon) appears at the Kα section of window 16. The calculator is reversed and disc 3 rotated until A appears at the Kα section of window 33. The coefficient of an element is found by reading off the value on scale 8, 9 or 35 as appropriate against the name of the element and multiplying it by the scale factor appearing at windows 28, 29 or 40, respectively. Where scale 35 overlaps scales 8 or 9, scale 35 is used. If a compound is to be analysed for presence of an element by determining the intensity of one of the K lines, the name of the element on scale 13 is placed against the reference line 10 on disc 1. At the window 16 appears the names of the emission lines of these elements which if present in the compound would enhance the K lines of the element under investigation. If the top disc 1 is rotated clockwise relative to disc 2 the names appearing at the window 16 are of those emission lines which cannot enhance the K lines of the investigated element, while if the disc 1 is rotated anticlockwise the names of other emission lines which enhance the K lines appear. The intensity of the enhancement decreases with the rotation. The window 33 and scale 50 on the reverse side of calculator can be used in the same way for investigation of the L lines. The three scales 8, 9 and 35 and the corresponding scale factors may be differently coloured.