étendue de mesure

14:53 Aug 14, 2012 

The definitions given certainly raise some interesting questions: suppose you have two 10V voltmeters, one analogue and the other digital. Ignoring mechanical friction and other sources of noise, this means that the "gamme" of the former is infinite, while that of the latter is strictly finite, though the "étendue" for each is the same. I don't believe that EN makes this distinction at all, though we do, of course, distinguish between accuracy and precision, which FR doesn't.
As a separate issue, it's well known that thermal resistance flow or velocity sensors are not good at low speeds, so it's puzzling to see a non-zero lower bound for velocity coupled with a zero lower bound for flow rate.

11:17 Aug 14, 2012 

Indeed, yes; however, according to the definitions Asker has found, the usage here would indeed be incorrect, since 'étendue' is described as being, in effect, the 'dynamic range' of the measurement, so would be described as a single dimensioned quantity such as 'X m/s' etc., not '0–X' as here.

09:06 Aug 14, 2012 

"Incorrect" use of étendue seems a bit harsh. One might say, for example, that measurements extend from x to y, or even that the extent of the measurements is from x to y. In patents especially (as Tony says), endless repetition of the same word can get very tedious, and a legitimate synonym is often a welcome relief!

06:17 Aug 14, 2012 

yes, if you can't come up with a sneaky special reason I don't know who can (that's a compliment).

16:55 Aug 13, 2012 

The definition you have found is consistent with my understanding of the terms in an EN context; and as you rightly point out, in your particular source text, both appear to be 'gammes' — I think the writer has probably just used 'étendue' incorrectly, probably for reasons of slavishly avoiding repetition!
However, that said, you really ought to check with your customer, in case there is some sneaky special reason here — though I can't for the life of me imagine what that might be!