壓電式加速度傳感器，又稱振動(dòng)傳感器，是基于壓電晶體的壓電效應(yīng)工作的。某些晶體在一定方向上受力變形時(shí)，其內(nèi)部會(huì)產(chǎn)生極化現(xiàn)象，同時(shí)在它的兩個(gè)表面上產(chǎn)生符號(hào)相反的電荷；當(dāng)外力去除后，又重新恢復(fù)到不帶電狀態(tài)，這種現(xiàn)象稱為“壓電效應(yīng)"，具有“壓電效應(yīng)"的晶體稱為壓電晶體。常用的壓電晶體有石英、壓電陶瓷等，在現(xiàn)代生產(chǎn)生活中被應(yīng)用于許許多多的方面，如手提電腦的硬盤抗摔保護(hù)，目前用的數(shù)碼相機(jī)和攝像機(jī)里，也有加速度傳感器，用來(lái)檢測(cè)拍攝時(shí)候的手部的振動(dòng)，并根據(jù)這些振動(dòng)，自動(dòng)調(diào)節(jié)相機(jī)的聚焦。壓電加速度傳感器還應(yīng)用于汽車安全氣囊、防抱死系統(tǒng)、牽引控制系統(tǒng)等安全性能方面。

美國(guó)Dytran的7705A1是一款微型加速度傳感器/振動(dòng)傳感器，集成了壓電和DC響應(yīng)技術(shù)，目前為止只有Dytran做到 。

Dytran’s new generation of sensors combines two technologies (piezoelectric and DC response MEMS), which until now have never been packaged simultaneously in a single housing.

The Dytran 7705A1 Extended Low Frequency (ELF™) accelerometer combines both a piezoelectric and a variable capacitance MEMS element, combined as a single output, to create the widest frequency response bandwidth in the industry, from DC (0 Hz) to 10 kHz. Unique ELF™ technology combines the most desirable features of piezoelectric sensors (excellent high frequency response) with those of variable capacitance accelerometers (true DC response), eliminating the need for using two different technologies to cover the bandwidth of interest in an application. Slow rotation speeds in the sub-1Hz range and gear mesh frequencies up to 10 kHz can now be made using the same sensor. The Dytran model 7705A1 ELF™ accelerometers are ideal for flight testing, ride quality, Health & Usage Monitoring Systems (HUMS), wind turbine measurements, machinery monitoring, and the widest range of structural response applications.

ELF™ accelerometer model 7705A1 is offered with a 200g range and operates on 5-28 VDC power at 7-9 mA of current. Signal/power is handled via a 4-pin M4.5 x 0.35 radial connector. The lightweight titanium housing weighs just 15 grams, and is hermetically sealed for use in rugged environments, from test tracks to outer space. The ELF™ incorporates a 10-32 tapped mounting hole and a hex base.