Considering that it is difficult to monitor the measurement system and amend the test parameters on the scene in shock wave overpressure measurement and it is inconvenient to operate and carry traditional PC in outdoor experiments, a new handheld terminal for shock wave pressure measurement system based on ARM is designed, The handheld terminal, whose ap- plication program is developed by the software of Qt, can control the measurement system by Wi-Fi and perform the functions of monitoring the system state, transmitting the data by wireless and displaying waveforms. To prevent data loss, USB inter- face is designed to read the data The test results show that the designed handheld terminal has good stability and reliability in several explosion experiments.
A noise reduction method for infrared detector output signal is studied during dynamic calibration of thermocou- pie. Firstly, the deficiency of the classical filter method is analyzed and the application of the wavelet analysis is introduced for signal de-noising during the dynamic testing. Secondly, the theoretical basis of wavelet analysis, the choice of wavelet base and the determination of decomposed series and threshold are analyzed. Finally, the de-noising experiment for infrared detector signal is carried out on the Matlab platform. The results indicate the proposed wavelet de-noising method is effective to remove fixed frequency and high-frequency noise; furthermore, good synchronization is achieved between the de-noised signal and the useful signal components in the original signal, which is of great significance to thermocouple modeling analys- is.
