If recalibrating a sprinkler system gauge rather than replacing it, at what percentage off must the gauge be replaced?

In a sprinkler system, maintaining accurate pressure measurements is essential for ensuring proper function and safety. If a gauge is found to be off, it is important to assess whether recalibration is sufficient or if replacement is necessary. The criteria for replacing a gauge usually involves how far off its readings are from the actual pressure.

The standard industry practice dictates that a gauge must be replaced when it is reading inaccurately by a significant margin. A deviation of 3% high or low indicates that the gauge may no longer provide reliable readings for the system’s operational needs. This threshold ensures that the measurement errors remain within acceptable limits, keeping the system functioning correctly and safely. Going beyond this margin could lead to issues with system performance, such as improper functioning of the sprinkler heads or failure to detect pressure problems.

In contrast, lower thresholds (like 1% or 5%) may not adequately address the need for reliability, while a higher threshold like 10% may risk significant errors in system operation. Therefore, recognizing that 3% is the key cutoff for reliability, it becomes clear why this is the correct answer.