Properly using potentiometers in a high-vibration application.
Back in September, Brian Tinham of PlantEngineer.org wrote an article about high-vibration position sensors and basically discounted the use of potentiometers for this application.
The article quotes Mark Howard from Zettlex: "Potentiometers are by far the most common form of position sensor, but are generally not suitable for environments with either extreme or prolonged vibration." But that all depends on your approach. When designed correctly, potentiometers are actually a wise choice for high-vibe jobs.
At Betatronix we have created wiper designs that address vibration issues by controlling our susceptibility to certain frequencies. If we know the operating frequency of a system, we can use our computer-aided design tools to make sure we are robust to that environment. We have created wipers with multiple sections each tuned to different frequencies so that we are always optimized for performance.
The article also mentions the issue of “damping,” saying that it can cause the sensor’s output to become an average of its measured position, which is obviously dangerous. However, damping is something that can be easily prevented in many applications. One way we do this is by filling the sensor body with oil. This prevents the averaging effect described in the article and makes for greater accuracy. It has worked for many projects we’ve worked on for clients in many industries.
To learn more about how potentiometers can help you overcome obstacles in your next project, talk to one of our expert engineers or representatives.