GB/T 12085.2-2022 is part of the series of standards for "Environmental Test Methods for Optics and Photonics," focusing on basic climatic environmental testing. This standard specifies test methods for optical instruments and their components under three typical environmental conditions: low temperature, high temperature, and humidity. It aims to evaluate their tolerance and operational stability under extreme temperature and humidity conditions. The standard is applicable to various optical and photonic instruments, including auxiliary components from other fields (such as mechanical, chemical, and electronic equipment). The key testing instrument for implementing this standard is the temperature and humidity test chamber, which can accurately simulate and control the required temperature and humidity environments to ensure the accuracy and repeatability of test conditions.