Pitot-gauges should be calibrated by a testing laboratory ____________.

Pitot gauges are crucial tools used in sprinkler systems for measuring the flow rate of water in pipes. The calibration of these gauges is essential to ensure accurate readings, which are vital for the design, installation, and maintenance of fire sprinkler systems.

Calibrating pitot gauges annually is appropriate because it provides a balance between ensuring accuracy and practicality. Frequent calibration, such as after each use or quarterly, may be excessive for most applications and could lead to unnecessary downtime or costs. Conversely, longer intervals, such as every five years, might not catch potential inaccuracies that could arise from wear or damage over time, leading to unreliable flow measurements.

In summary, annual calibration strikes a vital compromise that helps maintain the reliability and accuracy of the readings taken by the pitot gauge, ensuring safety and compliance with sprinkler system standards.