EEVblog #1300 - 'Parts Per' Notation EXPLAINED

"Per Mille" is a trap for young players.
"Parts Per" notation explained, along with percentage and ppm.

#Fundamentals #Tutorial

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[EEVblog]

I totally forgot to include CPM, or "Cost Per Mille" that you hear Youtubers talk about all the time. That's "Cost Per Thousand Impressions" or effectively "Revenue per thousand impressions". So a Youtuber might typically earn say $1 CPM, or $1 for every 1000 views.
And I just sprung it on Mrs EEVBlog who knew instantly it was per thousand, as she's chemist and it's used in various chemical concentrations.

[lp]

In Germany, almost everyone knows this unit because it is used for how much of your blood is affected by alcohol. And I think many people using it do not even know that it means "parts per thousand" but they use it anyway.

[unperrier]

‰ is actually more comfortable to work with because it fits nicely with standard system units which is based on power or thousands (pico, nano, micro, milli, kilo, mega, giga...) so basically 1‰ of 123 mA is 123 μA
ppm is equally good because it makes you drop yet another levels: 1ppm of 1V is 1μV
The other units (percent, per ten thousands) are not as nice for that reason (they don't drop a whole number levels of units)

[akuaku]

As a 1.4 PPM of your audience, I approve this video.

[pcfreak]

Honestly, as a European I thought this was a late April fool’s joke. Around here everyone is taught this in school and like others have said, is the official scale for BAC.

[AlistairSchofield]

I work in Mass Spectrometry and we're always dealing with ppb (parts per billion) for things like high voltage power supplies and the like!

[JonGretarB]

In the medical field it’s often referred to as promille or promil.

[extoprak]

I appreciate that you not only say but also write the variations like mil or mille, it helps a lot for non native english speakers like me.

[Herby-]

In financial stuff "basis points" are simply "percents of a percent" (or that's how I think of it), and your explanation is also correct.

[unperrier]

It's quite common in France. As a matter of fact, *_mille_* = a thousand in French!
In French we say:
• % *_pourcent_* from which _percent_ derives
• ‰ *_pour mille_* from which _per mille_ derives

[AppliedScience]

Interesting! Never seen that symbol before. Thanks.

[AndreDeLimburger]

I'm familiar with permille. Here in the Netherlands, the amount of alcohol in your blood you're allowed to drive is expressed in permille.

[thegame]

This is used in every european country i'm aware of to messure the blood alcohol level.

[SanderRuben]

Most interesting thing about this video for me was that you have never seen this before and you found it so strange that you made a video about it.

[Kaxlon]

Here in Sweden it's used for "unit alcohol/in blood".
Everyone with a drivers license knows of this unit. The cops use a alcohol meter which use per mille.
And if they need to draw blood then the same unit is used.
It's called "promille" in Swedish.
I have never seen it used in electronics though.

[mikepettengill]

You cleared up a lifetime of confusion around mil (thousands of an inch) and millimeters. Thank you.

[mdrolc]

"Basis points" has slightly more nuance to it.
Interest rate before: 2%, after: 1.95%. The interest rate dropped by 50 basis points. The interest rate dropped by 2.5%. The interest rate dropped by 0.5 percentage points.

Saying "points" implies simple subtraction from the original value when calculating a drop or a raise. Saying "percent" or "per mil" means a change of value relative to the original value. (after = before + percentage*before/100)

[Shadowstray]

You say that everyone instinctively learns an understand percentages, but please have a word with my boss who expects everyone to give 110% every day :)

[randomtask]

It's used often in Italy (and most of mainland Europe). It's useful and makes more sense when something is less than 1%. For example, 0.3% is clunky and prone to misinterpretation. 3‰ is easier to use and gives a clearer instant picture of the scale.
What is clearer: 'three in a thousand will die' or 'zero point three in a hundred will die'?

[Gloworm]

Mill(e)s are used in property tax rate. As a cost per $1000 of value.