The Type 8344 DeltaShear accelerometer from Bruel & Kjaer measures low levels of vibration effects in structures and machines. The unit combines high sensitivity with good frequency response. A built-in DeltaTron preamplifier allows the device to form part of a Fast Fourier Transform testing kit when coupled with the 2250 sound level meter and FFT data-analysis software. Integral electronics can be mounted on a test object with an M5 threaded steel stud. The design features three piezoelectric elements and three masses arranged in a triangle around a center post, which is bolted to the housing. The ring prestresses the piezoelectric elements to give a high degree of linearity. The signal is collected between the housing and the clamping ring and amplified by the preamplifier.