Calibration of the Low-Pressure Fuel Evaporative Tester (LPFET) requires which of the following gases?

The calibration of the Low-Pressure Fuel Evaporative Tester (LPFET) requires the use of nitrogen as it serves as a non-reactive gas for calibrating equipment dealing with fuel evaporation systems. Nitrogen is inert, meaning it does not react with other substances during the calibration process, allowing for accurate adjustments of the testing equipment without introducing variables that could affect the readings.

In the context of the LPFET, using nitrogen ensures that the calibration reflects the intended pressure and flow characteristics of the fuel system under evaluation, which is essential for obtaining reliable results during smog check inspections.

Other gases like low-range or high-range calibration gases may not provide the same stable properties as nitrogen, making them unsuitable for this specific application. Similarly, oxygen would not be appropriate for this calibration due to its reactive nature, which could alter the measurements or even pose safety risks during testing.