GB/T 2423.22-2012 "Environmental Testing - Part 2: Test Methods - Test N: Temperature Change" specifies the methods for temperature change testing (Test N) in environmental testing of electrical and electronic products. It is used to evaluate the adaptability of products under conditions of rapid temperature changes, primarily including Test Na (rapid temperature change with specified transition time) and Test Nb (temperature change with a specified rate of temperature change). The standard provides detailed specifications for test equipment, severity levels (such as temperature range, duration, transition time, or rate of change), and test procedures, aiming to assess the product's tolerance to the environmental effects of temperature changes.