| 摘要 |
FIELD: measurement equipment.SUBSTANCE: test specimen representing a smooth cylinder with the base diameter of 6 mm and height of 8 mm, turned from the test brick piece, is dried in a drying oven for 24 hours at 110°C. Within 72 hours after drying the specimens are impregnated with a magnetic fluid of 10-15% concentration. To impregnate the specimen, a magnetic fluid is used, which represents a colloid solution of magnetite nanoparticles in kerosene with volume share of magnetite 10-15%. This time is sufficient for the sample to be fully impregnated with the magnetic fluid. Further they measure curves of magnetisation of the cylinder impregnated with magnetic fluid, as well as of a sample of magnetic fluid with the same volume and shape as the cylinder, with the help of a vibratory magnetometer. Based on the produced magnetisation curves, they identify the magnetic moment of saturation of the cylinder impregnated with the magnetic fluid, and the sample of magnetic fluid of the same volume and shape as the cylinder. Further using the following formula the porosity P of the material, from which the cylinder is made, is defined:where m- magnetic moment of sample (brick cylinder) saturation, where the sample is impregnated with magnetic fluid, m- magnetic moment of saturation of the magnetic fluid sample of the same volume and the same shape as the impregnated sample.EFFECT: reduced material and time costs, labour intensiveness of measurement process and results processing, production of highly accurate measurement results.2 dwg |
