PPM: bolo: Re: Hodiny Elektrocas

[Jaromir Sukuba]

Ono to nie je celkom iba tak, zda sa, ze PPM a PPB su "phased out"
lebo su nejednoznacne. IMHO za tym stoja nasi americki priatielia,
ktori ani nevedia co ten B vlastne znamena. Ci bilion alebo miliardu.
Namatkou trebars ILAC ( https://ilac.org/ ) v dokumente
http://www.gcc-accreditation.org/api/documents/file/A2F99222F1B90690A41D90D71819AD73/download
odporuca nepouzivat PPM a PPB, citujem:
The uncertainty covered by the CMC shall be expressed as the expanded
uncertainty
having a coverage probability of approximately 95 %. The unit of the
uncertainty shall
always be the same as that of the measurand or in a term relative to
the measurand, e.g.,
percent, μV/V or part per 106. Because of the ambiguity of
definitions, the use of terms
“PPM” and “PPB” are not acceptable.

Sranda je, ze 'part per 10^6' je OK, ale PPM (part per million) je
nieco uplne, ale uplne ine a absolutne neakceptovatelne.
Samozrejme, ja im na to prdim a pouzivam PPM presne tam kde sa to hodi.

J.


st 16. 2. 2022 o 21:20 balu <balu na k-net.fr> napísal(a):
> ppm sa z nejakeho zahadneho dovodu v metrologii nemoze pouzivat.Vsade je
> uvadzane uV/V, us/s a podobne. Na skoleni v meteorologickom ustave v
> Karlovej Vsi (ako to niekto nazval) nam to obuchavali o hlavu. Kedze
> teraz pracujem v sekcii elektrickej metrologie musim dodrziavat
> konvencie :-)