Selection of shock acceleration sensor

Shock acceleration sensor is developed by MEMS technology and microelectronics technology. It integrates acceleration sensor, signal converter, power converter, signal filter circuit, saturation control and temperature compensation. It has the characteristics of micro volume, micro power consumption, micro noise, high integration, high stability, high reliability, low temperature drift and strong environmental adaptability.

Impact acceleration sensors are widely used in industrial automatic control, automobile, seismic measurement, military and aerospace systems. Due to the limitation of working environment, the impact acceleration sensor is required to have high resonant frequency and good dynamic performance to ensure that the impact force or impact acceleration of the measured object can be measured quickly and accurately. There are many structural forms of impact acceleration sensor, among which the more common are column and diaphragm structure. Impact acceleration sensor is a diaphragm structure with compass and sensitive mass in the center. At the position close to the maximum strain at the edge of the circular diaphragm, four resistance strips with the same resistance value are diffused along the radial 110 and tangential 110 by diffusion doping method, and the four resistors with the same performance are connected through the evaporated aluminum electrode to form a Wheatstone bridge.

Selection of sensitivity

The reference range is given in the product introduction of impact acceleration sensor, which is convenient for users to select appropriate products from many impact acceleration sensors with different sensitivity. The minimum acceleration measurement is also known as the minimum resolution. Considering the noise problem of post amplifier circuit, it should be far away from the minimum available value to ensure the best signal-to-noise ratio.

The maximum measurement limit shall consider the nonlinear influence of the impact acceleration sensor itself and the maximum output voltage of subsequent instruments. The estimation method is: maximum measured acceleration × Charge / voltage sensitivity of the sensor. Whether the above values exceed the maximum input charge / voltage value of the supporting instrument, it is recommended that if the measured acceleration range is known, it can be selected from the "reference range" in the sensor index (considering frequency response and weight). At the same time, when the frequency response and weight allow, the sensitivity can be considered

Frequency selection

The frequency response curve given by the impact acceleration sensor manufacturer shall be installed with screws. Generally speaking, the curve is divided into two parts: resonance frequency and working frequency. The use frequency setting values are given according to the sensitivity deviation, which are 10%, 5% and 3dB respectively. Resonance frequency is generally avoided, but there are some special cases, such as bearing fault detection.

The frequency of the impact acceleration sensor shall be higher than the vibration frequency of the measured object, and the frequency response of the impact acceleration sensor with frequency doubling analysis requirements shall be higher. Civil engineering belongs to low frequency, and the accelerometer can be selected at about 0.2 Hz ~ 1 kHz. Mechanical equipment is generally medium frequency. The frequency can be comprehensively estimated according to equipment speed, equipment stiffness and other factors, and an accelerometer of 0.5 Hz ~ 5 kHz can be selected. The frequency of impact measurement is very high.

Different installation methods of acceleration sensor will also change the frequency response (little effect on the vibration value). The installation surface shall be flat and clean, and the installation selection shall be based on the principle of convenience and safety. The weight and sensitivity of the acceleration sensor are inversely proportional to the frequency of use. It has high sensitivity, large weight and low use frequency, which is also the skill of choice. If you want to know more about micro acceleration sensors and acceleration sensors, you can pay attention to us.