Instrument for detecting calcium, silicon, and magnesium in stones and stone powderInstrument for detecting calcium, silicon, and magnesium in stones and stone powder

W---- Weight percentage content of the element in raw material

A---- Amplification factor

Elements such as calcium, iron, aluminum, and silicon emit their respective secondary characteristic X-rays when excited by the isotope Pu238. Among them, the secondary characteristic X-rays of calcium and iron, due to their relatively higher energy compared to those of aluminum and silicon, are referred to as high-energy secondary characteristic X-rays, while those of aluminum and silicon are termed low-energy secondary characteristic X-rays. The various characteristic X-rays are amplified by a proportional counter tube to produce their respective electrical pulses. Due to differences in energy, the resulting pulse voltages also vary. These electrical pulses are filtered by a specifically designed electronic discriminator to remove the pulses generated by low-energy characteristic X-rays, leaving only the pulses produced by the characteristic X-rays of calcium and iron. Since the atomic number of calcium is 40 and that of iron is 56, the difference between them is significant, resulting in a substantial difference in the energy of their characteristic X-rays. Consequently, their electrical pulse waves do not overlap and can be measured separately. The principle of X-ray fluorescence mass analysis is based on the fact that the height of the electrical pulse is proportional to the intensity of the secondary characteristic X-rays produced by the element. The relationship between the intensity of an element's characteristic X-rays and its content is as shown in Equation (1.1):