Maximise your IIoT installation success by choosing the right sensors
Where sensors were initially deployed to monitor the state of produced goods, predictive maintenance is a key contemporary driver for new sensing technology for industrial requirements. In this scenario, sensors keep check on machine health, alerting facility managers to pending failures and prompting pre-emptive maintenance or parts changes, with minimal impact to operations.
In this way, numerous applications for sensor technology can be seen as part of the migration towards an Industrial Internet of Things (IIoT), providing extra insight into manufacturing processes, with the goal of improving quality and/or optimising maintenance schedules to enhance machinery productivity and maximise ROI.
Temperature, force, rotation and positional sensing are among the technologies covered in a new whitepaper by Avnet Abacus and TE Connectivity, entitled ‘Deeper industrial automation insight when sensing processes for the IIoT’. The whitepaper provides example use cases for different sensors, contrasting the advantages and disadvantages of traditional and new versions of the technology. Key sensor selection criteria are also discussed, along with the principle sensor development trends for IIoT applications, which can be summarised as follows:
Pure analogue makes way for digital
While analogue sensors can be integrated into IIoT networks through PLCs, a broad range of digital sensors are being developed that can be integrated directly with MCUs, or attached directly to digital industrial networks.
Micro-Electro Mechanical systems (MEMs), tiny – mainly digital – silicon etched components, boasting low inertia and precision construction can now provide magnitudes of improvement in measurement accuracy over traditional analogue alternatives. For more on MEMs, also take a look at ‘A quick guide to powering smart objects with kinetic energy harvesting’.
Aligned to the transition from analogue to digital measurement is an increase in the number of sensors embedded inside a single device. An accurate silicon-based temperature sensor is often embedded alongside the main sensor. With short pathways and highly integrated electronics, these devices boast a low noise emission footprint while being protected against induced and emitted noise sources.
Notably, a single chip can now combine integrated analogue to digital signal conversion, power management and configuration functions. The majority of this integration comes at relatively little extra investment, meaning that as these types of combined digital sensors evolve, it has become less costly to deploy and connect them.
Thanks to the miniaturisation of silicon devices, an important advantage of today’s digital sensors is their exceptionally low power consumption, which frequently allows battery powered and wirelessly networked installations.
Today’s packaging technology allows the production of enclosed sensor assemblies that aren’t much larger than the sensing element embedded inside them. In turn this ensures that the sensing area is much closer to the physical parameter being measured, resulting in higher potential accuracy and reduced noise risk. One caveat is that when using silicon-based devices, their upper operating temperature is limited to approximately +125°C, so for temperature measurement requirements above this level, selecting analogue technologies such as NTC (negative temperature coefficient) thermistors and RTD (resistance temperature detector) may be better options.
For more detailed insight into sensor choices for IIoT applications, download this white paper. Capable of providing technical support and advice in the selection of components for many use cases that fall under the IIoT umbrella, Avnet Abacus is ideally placed to answer your sensor selection queries.