n.天文羅盤(pán)
A gyrocompass or astrocompass can be used to find true north, while being unaffected by stray magnetic fields, nearby electrical power circuits or nearby masses of ferrous metals. 旋轉(zhuǎn)羅盤(pán)或星象羅盤(pán)能夠用來(lái)發(fā)現(xiàn)真北極,在飄移磁場(chǎng)區(qū)域也不受影響,接近于電路或接近于鐵元素塊。
