second of arc

基本解释

One second of arc movement is one thirtieth of a millimetre.
一弧秒的移動是一毫米的三十分之一。
When rotatory table is control by step motor with 360:1 reduction rate worm barring gears, one second of arc resolution can be achieved.
儅步進電機通過360：1減速比蝸輪副控制鏇轉工作台時，可獲得1角秒的分辨率。
Dynamic process of current is controlled quickly by the first inverter, and arc polarity is controlled by the second inverter of arc welding power source.
弧銲電源一次逆變控制電流快速動態過程，二次逆變控制電弧極性。

The largest optical telescopes on earth can distinguish between things that are separated by about one second of arc (a 1, 296, 000th of the celestial equator).
ECONOMIST: Pulsars: In a wink The
Its resolution is 30 billionths of a second of arc.
ECONOMIST: Pulsars: In a wink