Shaken, Not Stirred—The Piezoelectric Effect and Oscilloscopes (.PDF Download)

Here’s some advice from an oscilloscope expert: Don’t hit your oscilloscope while making measurements (and preferably not ever). It seems like this should go without saying, right? But in late March, the electrical engineering community (and consequently my inbox) was abuzz. The well-known electronics YouTuber Dave Jones posted “EEVBlog #983 – A Shocking Oscilloscope Problem”:

Now, this made me stop in my tracks not because he’s highlighting an oscilloscope “problem,” but because after waiting for 982 videos, Dave thought this topic was finally worth using the word “shocking” as a pun. I don’t know about you, but if I made 982 videos, I would’ve played that card already. Although, our Keysight Oscilloscopes YouTube channel just broke 250 videos and we haven’t done it yet, so you never know.

Anyway, what triggered this video (pun intended; no, I’m not sorry)?  As it turns out, the topic is well (sigh) shocking.  Bumping an oscilloscope, or oscilloscope probe, the wrong way could cause mystery signals to appear on the screen. Not just some oscilloscopes—every oscilloscope. Why? Because the ceramic capacitors in the oscilloscope’s acquisition system are piezoelectric materials.