Which statement is true about nozzle flow rate changes after calibration?

• A. Flow rate could change due to age.
• B. Flow rate could change due to age and nozzle variation.
• C. Flow rate depends only on wind.
• D. Flow rate is never affected by nozzle wear.

Answer: (B)

Nozzle flow rate can drift after calibration because physical changes to the nozzle and its components happen with use. Over time, the orifice can wear, tips can erode, and deposits or chemical attack can alter the size of the opening. Those changes mean the same set pressure delivers a different actual flow rate than what was measured during calibration. In addition, even new nozzles vary a bit due to manufacturing tolerances, so two nozzles that started at the same target rate may behave slightly differently once in service. Wind and weather affect where the spray droplets go, not how much liquid is flowing from the nozzle at a given pressure, and wear can indeed change flow, so the statement that flow rate could change due to age and nozzle variation is the most accurate. Regular checks of flow at the calibrated pressure and replacing worn nozzles help maintain consistent application.