Designing a sensor for wireless condition monitoring is a complex balancing act between meeting performance requirements whilst adding the most value for the end user. The choice of technology becomes crucial when trying to optimize certain aspects of the design. Form over function, or vice versa is just one of the design directions that needs to be established very early in development. Thus, choosing an appropriate power source is one of the earliest decisions that needs to be made.

Batteries are available in all shapes and sizes, different chemistries, non-chargeable, re-chargeable, etc. However, the form factor of the power source will largely dictate the overall dimensions of the sensor. Many wireless sensors coming to market have very large batteries to meet the longevity requirements that are needed by customers to trend their equipment performance over many maintenance cycles. If a more power-hungry technology is used to perform measurements and serve the wireless communications, then the battery consumption will be substantial. However, a larger battery can have many knock-on effects. A larger battery adds additional weight and influences the center of gravity, which increases the size of the magnet or mounting bracket needed to fasten or secure the sensor, never mind the overall physical size of the sensor. It is difficult to describe how important and impactful this component selection is on the outcome of the product design.

The vibration analysts are calling out for smaller, compact sensors which means a tight balancing act between battery size and battery life. Most customers and product users are happy to concede a replaceable battery design, as a way of lengthening product service. However, this can often make ingress protection more challenging, as the design must allow easy access to change the battery but still maintain a high level of robustness. Having a small, lightweight, low center of gravity sensor with a compressed mounting footprint, will allow the sensor to fit into tighter and more “ideal” surface mounting locations. This is very important when measuring vibration and temperature close to the source of the vibration. To summarize, a high performing sensor, that you cannot mount correctly, has diminishing benefits in terms of machine health analysis. Ultimately, measurement performance and determination of early failure are very closely tied when it comes to adding the most value for the end user.