IEC 61300-2-48:2009详细说明了确定光纤设备或封闭件是否适合承受操作、储存和/或运输过程中可能发生的湿度和温度变化的程序。该测试旨在表明此类设备在暴露于高温和湿度下，然后进行短期冷冻时的性能。第二版的主要变化是增加了O类循环程序和严重性重新考虑。

IEC 61300-2-48:2009 details a procedure for determining the suitability of a fibre optic device or closure to withstand variations in humidity and temperature that may occur during operation, storage and/or transport. The test is intended to indicate the performance of such devices when exposed to heat and humidity followed by short-term freezing. The main changes to this second edition are the addition of the Category O cycle procedure and the severity reconsideration.