Water meters for cold potable water and hot water - Part 1: Metrological and technical requirements (ISO 4064-1:2024)

This publication establishes the foundational metrological and performance criteria for water meters measuring cold potable water, hot water, and chilled water consumption. It defines the classification of water meters into three distinct classes based on the relationship between permissible error limits and the flow rate. The scope covers single-jet and multi-jet water meters, as well as water meters equipped with an integrated flow conditioner, specifically designed for measuring water used for household and industrial applications. Detailed specifications are provided regarding the permissible error limits across various flow regimes, including the minimum flow rate, the transitional flow rate, and the flow rates at which the maximum flow rate is measured. Furthermore, the document outlines essential requirements for the design, construction, and marking of the measuring devices to ensure reliability and accuracy in commercial and utility billing scenarios. It incorporates international consensus on test methods to verify performance under different operating conditions, ensuring uniformity in measurement practices across diverse environments without referencing specific regional adoption dates or administrative bodies.