Feature

Makers and engineers: get to know your instrumentation amplifier for accurate IoT data capture

Sensing is where the Internet of Things (IoT) and the smart home begins, and it’s where DIYers, makers, and even professional designers run into their first problem.

03/10/2018 16:42:25

Font size:

Many inexpensive transducers such as accelerometers, force sensors, strain gauges, and pressure transducers are designed around resistive Wheatstone bridges, so their outputs are differential voltages in the
millivolt (mV) region.

To ensure the data that is captured is accurate, designers need to become familiar with the instrumentation amplifier (INA). This is a balanced differential amplifier
with easily controllable gain, low offset drift, and noise-cancelling properties.

Piezo-resistive transducers

One of the most popular families of transducers are those that use piezo-resistive elements. These
are used to measure strain, force, acceleration, and pressure, to name a few applications.

Small piezo-resistive elements are attached to the mechanical elements of the transducer. The desired
parameter sensed causes the mechanical structure to deform. The piezo-resistive elements undergo strain proportional to the sensed parameter which changes the elements’ electrical resistance.

Read the full article in the October issue of DPA

Written By Sophia Bell

Sophia Bell is the Group Editor of DPA, Connectivity, and PBSI. She joined the team in 2020 as Assistant Editor after achieving a First-Class Honours BA in English Literature and Film Studies from the University of East Anglia. In her current role, she leads the editorial strategy, driving digital growth and ensuring each title continues to deliver trusted, relevant insight for engineering and manufacturing professionals.