1、Sensors should be selected based on testing range, frequency response, usage requirements, etc.
2、Sensitive element: The sensitive element of our company's explosion pressure sensor is piezoelectric crystal, which is an internationally recognized method. Piezoelectric sensors have excellent characteristics: wide dynamic range, good anti-interference, high signal-to-noise ratio, good reliability, good linearity, wide frequency response, and good temperature characteristics. According to different sensor requirements, different piezoelectric crystals are used. After sensing the pressure impact, the piezoelectric crystal generates a charge (Q) by compressing the piezoelectric crystal with the diaphragm, which is then amplified using a charge amplifier.
3、IEPE built-in circuit pressure sensor: To overcome the interference problem caused by the long cable of existing charge type pressure sensors, a method of embedding a charge amplification circuit in the piezoelectric pressure sensor can effectively solve this problem. This method is called IEPE type pressure sensor, and the built-in circuit of the sensor adopts constant current power supply. The disadvantages of IEPE circuit are those its reliability is neither not as good as that of charge type sensors, nor the dynamic range is not as flexible as charge type sensors. 4、Resonant frequency: The nominal resonant frequency of a qualified sensor should be a clear resonant peak, and the secondary wave before the resonant peak should be much lower than the main peak. Our company uses micro explosives to explode to obtain the resonant frequency of the sensor, and this testing method is consistent with the shock tube testing of Aerospace 102 Institute. The frequency of use is about 70% of the resonant frequency (calculated based on the flat end before the resonant frequency). 5、Rise time: The shorter the time from the beginning to the maximum peak of the explosion waveform, the more it demonstrates the sensor's ability to quickly respond to explosions, which is particularly important for high-frequency sensors.
6、Sensitivity dynamic testing: Abandoning the commonly used method of obtaining sensitivity by adding weights to piston pressure gauges in China, all pressure sensors in our company adopt internationally recognized dynamic testing methods. The tested sensor and standard sensor are installed in a rigid hydraulic pulse cylinder and tested using impact measurement method. 7、Installation Method: It is recommended to use a combination of rigid and flexible installation methods. The fixture at the sensor installation site should have a certain stiffness to avoid shaking. On the basis of the stiffness, flexible materials should be padded. This method does not affect the accuracy of testing frequency and amplitude. If the gasket material has insulation, it can have a floating effect. It is recommended that the entire testing system adopt a single point grounding method for anti-interference purposes.
8、Long wire attenuation: Due to the high frequency of explosion pressure, the long wire of the sensor will have different signal attenuation at different frequencies. Our company provides targeted frequency/line length attenuation rates in the product manual. 9、Verification: After extensive testing, the sensor should be sent for inspection.
