2019 年 53 巻 p. 28-34
Acoustic Emission Measuring Method in which acoustic emission (AE) signals obtained from chemical reaction and phase transition are measured and analyzed is expected to be a new analytical method if used with the thermal analysis. The phase transitions of NH4Cl, NH4Br, NH4NO3, KNO3, and TlNO3, and the decomposition reaction of MgCl2・6H2O were observed by the method. The samples were dried at 50 or 100 ℃ and their particle sizes were sieved to be 74~177 µm before the measurement. As a result, it was found that there was the influence of the particle size in the AE measurement and that the intensity of AE signals was relative to amounts of sample at less than 450 mg because of echo at more than that weight. It was clarified that the AE measuring method could be estimated the phase transition which could not be detected by the thermal analysis.