Which GPM points must be calibrated on the return venturi's high range differential pressure transmitter?

The correct answer focuses on the specific flow rates that are significant in the calibration of a return venturi’s high range differential pressure transmitter. Points that are calibrated are typically those that correspond to critical operational thresholds where accurate measurements are essential for proper system performance. In this case, the selected points, which are 0, 560, and 700 GPM, are important because they likely represent the lower limit, a normal operational flow rate, and a higher operational flow rate within the expected performance range of the system.

The first point, 0 GPM, is essential to establish a baseline calibration for the transmitter when there is no flow. This ensures that the differential pressure measurement is zero when no fluid is present, which is crucial for accurate readings when flow begins. The next two points, at 560 and 700 GPM, provide reference points within the operating range that can ensure the transmitter accurately reflects changes in flow rate, allowing for precise monitoring and control of the system.

The other options present flow rate points that could either exceed the practical capabilities of the system or are not typically representative of the normal operating range used for calibration purposes. This can lead to inaccuracies in the system’s ability to monitor and control the flow effectively. Therefore, the