PSI - Issue 40

L.A. Prokopyev et al. / Procedia Structural Integrity 40 (2022) 365–371 Prokopyev L.A. at al. / Structural Integrity Procedia 00 (2022) 000 – 000

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emission sensors are selected with frequency regimes from 100 to 300 kHz and protected from the influence of low temperatures. The acoustic emission system uses the AE "Expert 2104" software. Time dependence of the acoustic emission total count under the local low-temperature loading is shown in Fig. 2.

Fig. 2. Time dependence of the acoustic emission total count under local low-temperature thermal loading.

The temperature field was determined using a precision signal converter of resistance thermometers and thermocouples "Terkon" manufactured by LLC "Termeks". Copper-constantan thermocouples were used, installed according to the scheme shown in Figure 1. The voltage signals from thermocouples are measured by correlation with the reference voltage installed in the instrument. Measurement of resistances of thermistors is made by comparison with reference resistance. A built-in analog-to-digital converter converts data to digital code. In turn, the microprocessor converts the digital code into a temperature value in Celsius. The result is displayed on a digital display and sent to a computer using the RS-232 interface. Time dependence of the temperature data from the sensors during the cooling of the specimen by a low temperature carbon dioxide is shown in fig.3.