弗赖堡矿山研究院研制的VLF-M01型甚低频仪,同时将电场强度或磁场强度混放在两个波道线路里,并且能够确定两个毗连信号的相位差。以上三项测量值均可在显示器上读出,亦可用墨水记录器或磁带记录器记录,因为所显示的测值同时作为模拟电压毗连于一个分离的输出端上。因此,该仪器 The VLF-M01 VLF instrument, developed by the Freiburg Mining Institute, combines electric field strength or magnetic field strength in two channel circuits and determines the phase difference between two adjacent signals. All three of the above measurements can be read on the display or recorded by an ink or tape recorder since the measured values ​​are simultaneously applied as analog voltages to a separate output. Therefore, the instrument