Leak testing can be done by any of the following methods EXCEPT: a. Sniffer testing. b. Dye testing. c. Pressure testing d. Nitrogen testing

The correct answer is d. Nitrogen testing.Leak testing is a process used to detect and identify leaks in various systems, such as pipelines, tanks, and containers. There are several methods used for leak testing, including sniffer testing, dye testing, and pressure testing.Sniffer testing involves using a device called a sniffer, which detects the presence of gas or vapor leaks by sensing the concentration of the gas or vapor in the air. Dye testing involves injecting a fluorescent dye into the system and then using ultraviolet light to detect any leaks, as the dye will glow under the light. Pressure testing involves pressurizing the system and then monitoring the pressure to detect any drops, which may indicate a leak.Nitrogen testing is not a recognized method for leak testing.