magnetic field – Hall probe
Used like a wand and moved in magnetic fields. Interesting in the way it measures the unseen. Has a niche use in applications showing magnetic field changing over time or some electrical variable.
![](https://www.rogerfrost.com/wp-content/uploads/2018/11/intrigue1.png)
![](https://www.rogerfrost.com/wp-content/uploads/2018/11/used1.png)
I’ve rated these sensors but your assessment will be different. I give a score, out of five, for the sensor’s intrigue, interest, and learning potential. I also give a score for how often a science department might use it.