{"id":5190,"date":"2024-10-12T08:59:40","date_gmt":"2024-10-12T08:59:40","guid":{"rendered":"https:\/\/www.bmagmeter.com\/?p=5190"},"modified":"2024-10-15T08:09:16","modified_gmt":"2024-10-15T08:09:16","slug":"comprehensive-understanding-water-meter-accuracy-class","status":"publish","type":"post","link":"https:\/\/www.bmagmeter.com\/nl\/comprehensive-understanding-water-meter-accuracy-class\/","title":{"rendered":"Comprehensive Understanding Water Meter Accuracy Class"},"content":{"rendered":"

Water meter accuracy class is a crucial parameter that defines the precision of a water meter’s measurements. It indicates the maximum permissible error (MPE) in the meter’s readings at different flow rates. Simply, it tells us how close the meter’s measurement is to the actual water volume passing through it.<\/p>\n\n\n\n

Modern water meter accuracy standards, such as ISO 4064:2014, classify water meters into two main accuracy classes: Class 1 and Class 2. Class 1 meters are more precise than Class 2 meters. This classification is essential for residential water meter accuracy and various other applications.<\/p>\n\n\n\n

Standards Defining Water Meter Accuracy Classes<\/strong><\/h2>\n\n\n\n

Several international standards define water meter accuracy classes. Let’s look at the requirements specified in each:<\/p>\n\n\n\n

ISO 4064-1:2014<\/strong> & OIML R 49:2013<\/strong><\/h3>\n\n\n\n

Accuracy class 1 water meters<\/strong>:<\/h4>\n\n\n\n
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The MPE for the upper flow rate zone (Q<\/em>2\u2264Q<\/em>\u2264Q<\/em>4) is \u00b11 %, for temperatures from 0.1 \u00b0C to 30 \u00b0C, and \u00b12 % for temperatures greater than 30 \u00b0C.<\/p>\n\n\n\n

The MPE for the lower flow rate zone (Q<\/em>1\u2264Q<\/em>< Q2) is \u00b13 % regardless of the temperature range.<\/p>\n<\/blockquote>\n\n\n\n

The MPE for the upper flow rate zone (Q2\u2264Q\u2264Q4) is \u00b11 %, for temperatures from 0.1 \u00b0C to 30 \u00b0C, and \u00b12 % for temperatures greater than 30 \u00b0C.
The MPE for the lower flow rate zone (Q1\u2264Q< Q2) is \u00b13 % regardless of the temperature range.<\/pre>\n\n\n\n
Accuracy class 2 water meters<\/strong>:<\/h4>\n\n\n\n
The MPE for the upper flow rate zone (Q2\u2264Q\u2264Q4) is \u00b12 %, for temperatures from 0.1 \u00b0C to 30 \u00b0C, and \u00b13 % for temperatures greater than 30 \u00b0C.
The MPE for the lower flow rate zone (Q1\u2264Q< Q2) is \u00b15 % regardless of the temperature range.<\/pre>\n\n\n\n
MPE<\/strong> stands for Maximum Permissible Error<\/strong><\/p>\n\n\n\n
\"BMAG<\/a>
BMAG water meter accuracy class 2<\/figcaption><\/figure>\n\n\n\n
AWWA C700 Series<\/strong><\/h3>\n\n\n\n
The American Water Works Association (AWWA) standards provide detailed accuracy requirements for different types of water meters. While they don’t use the Class 1 and Class 2 terminology, they specify accuracy requirements for various flow rates: <\/p>\n\n\n\n
AWWA C700 (Displacement-Type meters):<\/strong><\/h4>\n\n\n\n
Normal test flow rates: \u00b11.5%
Intermediate test flow rates: \u00b12.0%
Low test flow rates: \u00b13.0%<\/p>\n\n\n\n
AWWA C701 (Turbine-Type meters):<\/strong><\/h4>\n\n\n\n
Normal test flow rates: \u00b11.5%
Intermediate test flow rates: \u00b12.0%
Low test flow rates: \u00b15.0%<\/p>\n\n\n\n
Old Water Meter Accuracy Standards: Class A, B, C, and D<\/h3>\n\n\n\n
Before the introduction of the new Class 1 and Class 2 system, water meters were classified as A, B, C, and D. This old system was defined in the ISO 4064:1993 standard. Here are the details of the old classification:<\/p>\n\n\n\n
\"water<\/a>
water meter accuracy class B<\/figcaption><\/figure>\n\n\n\n
Class A is the lowest and Class D is the highest.<\/p>\n\n\n\n
Lower zone (Qmin to Qt): \u00b15%
Upper zone (Qt to Qmax): \u00b12%<\/p>\n\n\n\n