What is the acceptable accuracy range for small residential water meters?

• A. 95% to 105%
• B. 98.5% to 101%
• C. 90% to 110%
• D. 100% to 105%

Answer: (B)

Meter accuracy is the percent of the actual water volume that the meter records. For small residential meters, this is kept very tight so customers are billed fairly and the utility can rely on the measurement.

The accepted range is about 98.5% to 101% of the actual volume. In practical terms, if 100 gallons actually flow, the meter should display between 98.5 and 101 gallons. It can under-record slightly (down to 1.5% low) or over-record slightly (up to 1% high) within the tested conditions. This narrow band reflects normal, acceptable variation from wear, temperature, and flow characteristics, while preventing significant underbilling or overbilling over time.

Wider tolerances, like ±5% or ±10%, would permit substantial billing errors, and a range restricted to 100% to 105% would exclude any under-reading, which isn’t realistic for real-world meters.