Based on the analysis of shortcomings existed in quasi-δ function calibration method, a dynamic calibration method was proposed. In this method, a pressure sensor was under high static pressure in advance, and then a bullet was used to impact Hopkinson bar for generating a quasi-δ function signal with small amplitude, which excited the sensor being calibrated, and finally a frequency response characteristics of the sensor was obtained. The principle of quasi-δ function dynamic calibration method was introduced. The relation of pulse-width of quasi-δ function signal, calibrated frequency range, and calibration precision was analyzed. The dynamic calibration system was established. This calibration method realized dynamic calibration of high pressure sensor under actual working pressure, and realized the tracing from zero frequency to a certain frequency needed. On the current technical level, the maximum static pressure is 800 MPa, the pulse width of the quasi-δ function signal is within 7 μs to 10 μs, the calibrated frequency range is from 0 to 20 kHz, and calibration error of amplitude-frequency characteristics is 5%.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |