Rotary piston gas meters have been manufactured since 1930 by Aerzener Maschinenfabrik, one of the largest and oldest manufacturers worldwide. The basis for the design of the gas meter series is from many years of experience and continual dialogue with the end users, as well as using the harmonized EU-standards which will apply to all installations within the European Market. They are manufactured in accordance wiht the Aerzen tradition for quality corresponding to the quality assurance system, certified to DIN ISO 9001 and as per pressure device guideline DGRL 97/23/EG.