測功機應有滾筒轉(zhuǎn)速測量裝置嗎%e6%b5%8b%e5%8a%9f%e6%9c%ba%e5%ba%94%e6%9c%89%e6%bb%9a%e7%ad%92%e8%bd%ac%e9%80%9f%e6%b5%8b%e9%87%8f%e8%a3%85%e7%bd%ae%e5%90%97