Transducers Trends - Part 2 of 3 by Glenn Pietila

Walking through the SAE NVH expo hall with a focus on transducers, it is clear that the transducer market is dominated by IEPE piezoelectric transducers (http://www.sensorsmag.com/articles/0505/14/main.shtml). For those who may not be familiar with the IEPE technology: IEPE is a piezoelectric transducer that has a small circuit built into it that helps to reduce the effect of cable length on signal quality and adds the convenience of not needing an external charge amplifier to amplify the transducer output before acquiring the signal.

Most data acquisition systems have integrated signal conditioning that supply the small current (generally in the 15 mA range) needed to power these internal circuits. Based on the number and variety of IEPE transducers available, it is clear that the convenience and low cost of these transducers is being realized by a large number of end users. As new ideas and technologies trickle out, there is also a major focus to develop transducers which provide better packaging for small, low-mass applications.

New piezoelectric transducers are becoming increasingly tiny (as small as 0.2 gm!) and inexpensive. These new developments allow for new applications such as surface-mounted microphones for measurements in tight spaces, and disposable shock and vibration transducers designed for freight industry use, as well as in-vehicle crash and abuse analysis. Continuing advancements in microchip technology continue to drive cost and size down, allowing further development in the transducer arena.