Which of the following statements is true about pressure differences between meters and provers during testing?

A large pressure difference between meters and provers during testing can indeed indicate a malfunction. When conducting measurement verification, the pressure difference should typically remain within acceptable limits for accuracy. If there is a significant discrepancy, it may suggest issues such as blockages, leaks, or incorrect calibration in the metering system, which could lead to unreliable measurements.

In contrast, while the initial pressure difference may seem irrelevant in some cases, it can actually influence the overall accuracy and performance of the system. Maintaining a constant pressure difference is crucial for ensuring measurement consistency; fluctuations can affect results. Lastly, although documenting variations in pressure can be useful, it does not absolve the need for the pressure difference to remain stable during testing to ensure accurate and reliable measurements.