Attaching yourself to your live circuit with a wearable instrument adds unnecessary risk.
Last week, I learned of a Kickstarter project from a comment by Kenneth Wyatt in his article Try an oscilloscope for under $200. Wyatt provided a link to what seems like an ingenious instrument -- an oscilloscope that you can wear on your wrist like a watch. From the comments there, on the project's Kickstarter page (Wyatt provides link in his comment), and from Maker Faire 2013: Tiny Oscilloscopes With OLED Screens, the wearable instrument sounds like a great idea.
The inventor, Gabriel Anzziani, is less than $2,000 short of his goal of $60,000 with five days to go. I expect he'll reach his goal. Anzziani is no stranger to designing tiny oscilloscopes, having designed the pocket-sized Xprotolab.
I've seen many pocket-sized instruments, particularly multimeters and the oscilloscopes that Wyatt covers in his article, but none so small that you can wear it on your wrist. If you wear your test instrument, the likelihood that a colleague will steal it from your bench is about nil. That's the good part.
The bad part also comes from the fact that you can wear the oscilloscope. Take a look at the video below, paying attention at time 1:57.
At points in the video, Anzziani has the oscilloscope watch on a bench next to a circuit. That's fine, but you don't need a wearable test instrument for that. At 1:57, however, you can see two wires connected to the instrument while it's on his wrist. That's the problem. As long as you don't move while the oscilloscope is connected and you're wearing it, all is well. But what if you get distracted and move? Several things could happen.
- The probes disconnect. No problem, just reconnect them.
- The probes break. Do you have replacements?
- The probes remain attached to the oscilloscope and to the circuit under test. When you move, the circuit goes flying and either breaks or causes a short that fries it, or worse.
What if the flying circuit accidentally touches a live wire with, say, AC mains power? What if the circuit burns and catches fire? Now you have a safety hazard. Is the convenience of wearing your test equipment worth the risk? To me, the oscilloscope watch is an accident waiting to happen.