Hacker News Reader

Comment by JshWright | Hacker News Reader

"Until I met Daniel, I actually didn't know that "smoke testing" was a term with a literal smoke-related meaning. I'd always heard it used in the context of software tests. Daniel used a tracing technique to follow a problem to its source, instead of just making random guesses."

I've always known "smoke testing" to refer to the mythical magic smoke that makes all electronics work. Smoke testing is turning something on for the first time to see if you're going to let the magic smoke out.

View on HN

This- I knew the electrical sense that early software engineers working on hobby computers probably got it from, where it refers to wiring something up, plugging it in for the first time and seeing if it lights on fire / creates smoke.

I guess there is a dual origin though

https://medium.com/@AikoPath/about-the-origin-of-smoke-testi...

That reminds me of a story[0] my digital electronics instructor once told me. He was on a team working on satellite[1] electronics and had the whole thing laid out on breadboard. It wasn't working, and they suspected it was a short, but with so many connections everywhere it would take forever to find. So they decided to crank up the input current until the short started burning and locate it that way. It apparently didn't cause anything to smoke, but eventually someone did notice the orange-hot wire that was causing the problem.

[0] I have a terrible memory so details may be incorrect.

[1] IIRC this guy had worked on geostar satellites and the hubble, but I'm not sure if this story was about either.

Yeah, this is not uncommon as a testing technique. Fuse keeps blowing? Replace it with a bigger fuse (or a heavy gauge wire) and eventually something else will pop (hopefully the bad component).

I've also heard 'smoke testing' refer to sending power to a device or component to see if any magic smoke comes out.

But... I've also seen smoke testing used in automotive and engine diagnostics which could predate or parallel this usage in electronics.

https://mechanics.stackexchange.com/questions/26749/what-is-...

I should imagine this method of troubleshooting sealed hollow-body systems of any kind have been around for a long time.

a quick search yielded a wiki article stating the method being used for sewers since at 1875.

https://en.wikipedia.org/wiki/Smoke_testing_(mechanical)#cit...

edit: format

Tangential-ish:

I used to live in a place where we had gas resources and gas stoves. Gas pipes would be painted yellow to stand out and people always had some sort of respect and caution around them - you don't mess with gas pipes - I learned that as a kid. At the slightest whif of gas people would light up a match or a lighter and run it along the pipe to check for leaks - I always thought this is what "smoke testing" meant (altho there would't be any smoke). I still don't know if this is safe or would even work or it's just something people did and keep doing... and I have no gas pipes around me anymore.

for the love of god if you smell gas please don't light a match to check. Real quick way to blow your house up if you do have a gas leak.

I remember watching my grandfather spit on pipes to find the source of a leak. It was viscous enough that it would bubble up. Taking flame to a gas pipe sounds absolutely terrifying.

> At the slightest whif of gas people would light up a match or a lighter and run it along the pipe to check for leaks

What is this? Some kind of Tom & Jerry show? Light a match near a leaking gas pipe and BOOOM!!!

Use soapy water instead and watch for bubbles. Less exciting but much safer.

I recently learned that there is such a thing as "gas leak detector". Bah, looks like fancy soapy water to me. Looked up such things, and it turns out that soapy water can cause corrosion and other bad things. "Gas leak detector" also works at sub-zero Fahrenheit temperatures if one needs to check refrigerant lines. On top of that, I bought some because I need to somewhat regularly crack a propane line on the RV/camper, and it was all of $5 for what is probably a year's supply.

It even pre-dates plumbing - https://en.wikipedia.org/wiki/Smoke_testing_(mechanical) is a good overview.

Reply on news.ycombinator.com