frequency recorder

例句：

1. 1. The frequency recorder is used to measure the frequency of sound waves.
   频率记录仪用于测量声波的频率。
2. 2.The frequency recorder was used to analyze the data collected from the experiment.
   频率记录仪被用来分析实验收集到的数据。
3. 3.The frequency recorder can be used to detect and measure the frequency of various types of signals.
   频率记录仪可以用来检测和测量各种类型信号的频率。