ISO 20492:2008建立了两种方法，用于测试预组装、永久密封的中空玻璃单元或故意打开毛细管的中空玻璃单元的抗雾性。这两种方法分别被指定为北美等市场的方法1和欧洲等市场的方法2。 由于测试限制，ISO 20492:2008不适用于含有拱肩玻璃涂层的密封中空玻璃装置。 ISO 20492:2008不适用于仅具有装饰功能的中空玻璃（IG）装置。

ISO 20492:2008 establishes two methods for testing the resistance to fogging of pre-assembled, permanently sealed insulating glass units or insulating glass units with capillary tubes intentionally left open. The two methods are designated as approach 1 for markets such as North America, and approach 2 for markets such as Europe. ISO 20492:2008 is not applicable to sealed, insulating glass units containing a spandrel glass coating due to testing limitations. ISO 20492:2008 does not apply to insulating glass (IG) units whose function is decorative only.