1 sentence

1. 这种新型声呐设备的声阻抗被精确控制在五十个瑞以内。

   zhè zhǒng xīn​xíng shēng​nà shè​bèi de shēng zǔ​kàng bèi jīng​què kòng​zhì zài wǔ​shí gè ruì yǐ​nèi.

   The acoustic impedance of this new type of sonar equipment is precisely controlled within fifty Rayls.

   Source: Dong Chinese Dictionary