How often have you come across the parts per thousand symbol?

Yeah, I've come across that at least a few times but it's often more common to see percent or ppm ... seems there is little love for per mille ‰.

Definitely agree on percent and ppm being the most common. If I have come across it before I probably read it as percent *cringe*

Wow.  I never knew about that symbol.  And now that my eyesight is getting worse with age I really do fear that one day I will mistake it for a percentage sign.

It's the go-to Unit Of Measure for alcohol tests and related laws here

Never.

I would have missed that in the spec table.  Use of it that way seems to obfuscate things based on the way instruments are normally spec’ed.  Or maybe that’s a typo (misuse of a symbol).

It could be the new Snellen chart

'cover your left eye please...'

%

‰ 

‱ 

'and now the right eye...'

Fascinating didn't know that either!

https://en.wikipedia.org/wiki/Blood_alcohol_content

I definitely missed it the first few times I glanced over the specifications. I assume you are correct in that it was likely a typo. I'm not sure I have ever seen it used in technical literature related to electrical & computer engineering or I have always mistaken the symbol as percent, not sure!

If they intended 0.2 parts per thousands, I wish they would have quoted it as 200 PPM, even though that would likely be too good to be true...

Indeed.  LOL