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用高性能的等离子电弧使天线窗暴露于加热率高达3000英热单位/英尺~2·秒环境中,而同时使电磁波通过天线窗透射出来。通过对范围很广的试验环境进行仔细的选择,可以产生模拟飞行条件的材料温度和表面条件。等离子弧熄灭以后立即进行了射频试验测量,把试验前与试验后的测量结果进行比较,就能得出由于高温和表面特性而产生的透射损失的定量数据。已经研究出的一些数据分析方法能把这些测量数据换算成损耗角正切值随温度变化的关系曲线,温度高到接近于烧蚀温度。曾对热压氮化硼成功地进行过试验,所得结果曾用来说明异常飞行持性。这种试验法也曾经用来鉴定天线窗的某些新候选材料。
The high performance plasma arc exposes the antenna window to a heating rate of up to 3000 British thermal units per ft 2 sec while transmitting electromagnetic waves through the antenna window. Careful selection of a wide range of test environments can produce material temperature and surface conditions that simulate flight conditions. Radio frequency test measurements were taken immediately after the plasma arc extinguished, and quantitative data on transmission losses due to high temperatures and surface properties were obtained by comparing the pre-test and post-test measurements. Some data analysis methods that have been developed can convert these measurement data into a curve of the loss tangent with temperature and the temperature is close to the ablation temperature. Experiments were successfully conducted on hot-pressed boron nitride and the results obtained were used to illustrate the abnormality of the flying behavior. This test method has also been used to identify certain new candidates for antenna windows.