erinevate gabariitmõõtmetega ja/või erineva voomääraga gaasiarvestite rühm, kus kõigil arvestil on järgmised omadused: sama tootja, mõõteosa geomeetriline sarnasus, sama mõõteprintsiip, ligikaudu samad karakteristikud Qmax/Qmin ja Qmax/Qt, sama täpsusklass, sama elektrooniline seade iga erineva gabariitmõõtmega arvesti jaoks, kasutades samu metroloogilisi tarkvararakendusi, mis on arvesti toimivuse seisukohast kriitilise tähtsusega, sarnane disaini- ja komponentkomplekti standard ning samad materjalid arvesti komponentide jaoks, mis on kriitilise tähtsusega, group of gas meters of different sizes and/or different flow rates, in which all the meters shall have the following characteristics: the same manufacturer, geometric similarity of the measuring part, the same metering principle, roughly the same ratios Qmax/Qmin and Qmax/Qt, the same accuracy class, the same electronic device for each meter size and using the same metrological software routines (if applicable) for those components that are critical to the performance of the meter, a similar standard of design and component assembly, and the same materials for those components that are critical to the performance of the meter