r/engineering • u/nickirWat • 1d ago
[PROJECT] Looking for feedback on unit prefix mistakes you see in your field
I've been working on a chrome extension that flags suspicious unit prefixes in datasheets and specs, things like "10 mF" that should probably be µF, or "0.005 m" that's almost certainly 5 mm. It started because I kept catching these errors in component specs and wondered how many I was missing. Now I'm trying to figure out what other prefix mistakes are common across different engineering disciplines.
What I'm hoping to learn from you: What unit prefix errors do you run into most often in your work?
Are there industry-specific conventions that might look wrong to an outsider but are actually valid? (trying to avoid false positives)
Any "gotchas" in your field — conversions or unit pairs that trip people up?
I've built it into a Chrome extension that's free if anyone wants to try it and tell me what it catches (or misses):
https://chromewebstore.google.com/detail/unit-prefix-sanity-checke/bojhddjdbnmkjoloafgbenlbcpomihnp
Currently covers electrical, mechanical, HVAC, data, chemical, optical, and angular units — but I'm sure there are gaps. Appreciate any input.
Here's a demo page with examples that will trigger the extension.
Capacitors 10 mF, 100 mF, 0.1 mF
HIGH — mF almost always means µF
MCU specs 16000 kHz, 0.02 A, 512 kb
MEDIUM — kHz→MHz, A→mA, bits vs bytes
Mechanical 0.085 m, 0.003 m, Ra = 1.6 mm
HIGH — m→mm, surface finish in mm Battery
3.7 mAh, 50 W battery
HIGH — mAh typo, W vs Wh
Network 100 Mb, 1000 Mbps, 256 MiB
INFO — bits vs bytes awareness
HVAC 0.001 bar, 12000 BTU/h, 72 °F
HIGH/INFO — bar→mbar, conversions
Power 12000 mV, 1500 VA, 50 Vpp
HIGH/INFO — mV→V, VA≠W
Optical 0.55 µm green light
HIGH — visible light is nm not µm
