SmartMeter is a "non-moving" parts water meter and because it has no-moving parts, nothing can ever wear out. On the other hand, conventional mechanical meters have many moving parts and with time, the parts wear out. As a consequence, the water flow measurement becomes less and less inaccurate and after a relatively short time period, the mechanical meter may "under-record" up to 25% in the first few years of operation. SmartMeter however, because nothing can wear out, maintains its 'linear' accuracy from day one up to say > 20 + years.