ultralow frequency meaning in English

超低频

Clinical and mechanical studies progress on treatment of malignant tumour by ultralow frequency pulsed - gradient magnetic fields
半梯度磁场治疗恶性肿瘤的临床和机理研究进展
Series of general - purpse instruments : including series of 2800 and 2500 electronics compoment parameters testing meter and related products ; series of 1630 function signal generator ; 1250 ultralow frequency spectrum analyzer and signal generator
通用类仪器系列：包括2800系列、 2500系列元件参数测量仪及其配套产品； 1630系列函数信号发生器； 1250超低频系列频谱分析仪及信号源。