What is the maximum allowable difference between the gauge and flow meter readings compared to actual pitot tube readings?

The maximum allowable difference between the gauge and flow meter readings compared to actual pitot tube readings is typically established to ensure the accuracy and reliability of the water supply operation. A difference of 10% is recognized as acceptable because it allows for minor variances that can arise from measurement errors or instrument calibration. This tolerance ensures that operators can rely on their flow readings to make critical decisions without being misled by excessive discrepancies.

This standard is critical in maintaining operational safety and effectiveness, as significant deviations could lead to underestimating or overestimating water supply capabilities, potentially compromising firefighting efforts or other operations relying on accurate flow data. A threshold of 10% balances the need for precision in measurements while accommodating standard operational tolerances inherent in measurement devices.