How should the water flow meter accuracy be checked, and how often?

• A. With a stopwatch and graduated cylinder; quarterly
• B. By reading the digital display only
• C. With a calibrated flow sensor; monthly
• D. With a ruler and timer; semi-annually

Answer: (A)

Direct verification of the flow meter’s accuracy comes from measuring actual flow with independent tools rather than reading the display. To perform it, run water through the meter and collect a known volume in a graduated cylinder while timing the delivery with a stopwatch. Calculate the flow rate from volume divided by time and compare it to the meter’s rated value. This direct, volumetric check reveals any drift, scale error, or sensor fault that could be missed if you relied on the readout alone. A calibrated flow sensor could be used for calibration checks, but for routine QA the straightforward stopwatch-and-graduated-cylinder method provides a reliable, practical verification with common lab tools. Reading the digital display only won’t confirm accuracy, and using a ruler with a timer doesn’t measure actual flow. The quarterly interval balances catching drift without overburdening the workflow.