China's vibration measurement has reached the international advanced level

On June 6, the "0.1Hz-50kHz vibration amplitude and phase measurement reference system research and establishment" developed by the China Institute of Metrology passed the expert appraisal. Experts believe that the main technical indicators of this research achievement have reached the international advanced level, and some of the indicators have reached the international leading level.

The new national vibration reference and phase characteristics national reference system is a technical improvement project of the AQSIQ, which includes vibration high frequency (2kHz-50kHz) reference, intermediate frequency (20Hz-2kHz) reference, low frequency (10Hz-10kHz) horizontal and vertical. To the benchmark.

Vibration measurements are part of the dynamic measurement. It is widely used in many fields such as mechanical fault diagnosis and monitoring, modal analysis technology, seismic and object detection. With the rapid development of the national economy and high technology, vibration measurement not only requires measuring the amplitude-frequency characteristics of the sensor, but also requires testing its phase-frequency characteristics at the same time. In order to meet the needs, the scientific and technical personnel of the Institute of Mechanics and Acoustics of the Institute of Metrology completed the research of the subject after three years of efforts and achieved a number of innovative technological achievements.

In the low-frequency vertical sub-reference amplitude-phase characteristic measurement system, a low-frequency vibration standard set was developed. In the Asia-Pacific region, the zero-difference sinusoidal approximation method of dynamic phase demodulation was used for the first time, and the acceleration sensitivity amplitude and phase shift measurement were realized by 1Hz. A technological breakthrough that extends to 0.1 Hz. The heterodyne time interval method based on peak and valley, the improved heterodyne sinusoidal approximation method and the improved homodyne interval method have been proposed and implemented independently. It has made breakthroughs in theoretical research and reached the international leading level.

On the piezoelectric high-frequency (2kHz-50kHz) vibration table, the heterodyne technology was used for the first time at home and abroad, and the sensitivity amplitude and phase shift of the nano-scale vibration sensor in the range of amplitude (1~500) nm were realized.

On the electromagnetic vibration table of the intermediate frequency vibration reference, the heterodyne technology was adopted for the first time in China, and the sensitivity amplitude and phase characteristics were calibrated. The intermediate frequency reference was extended from 20H-2kHz to 10Hz-10kHz.

Based on the results of this research, the three sets of high, medium and low benchmarks (sub-benchmarks) have achieved bilateral comparisons with the German Institute of Physics and Technology (PTB) sensitivity amplitude and phase characteristics from 10 Hz to 10 kHz, which is the highest vibration for international mutual recognition in China. Calibration capability (CMC) provides an important technical basis.