revolution indicator meaning in English

示转器
转数表
转数计
转数指示器
转速指示器
转效指示器

Propeller shaft revolution indicator
螺桨轴转速计
Shipbuilding - propeller shaft revolution indicators - electric type and electronic type
造船.推进器轴转速表.电动和电子类
On the bridge main engine instrument board , there is main engine cooling water thermometer , lub oil pressure gauge , main engine revolution indicator , main engine emergency shutdown pushbutton , and there is audible and visual alarm device for main engine lub oil low pressure , cooling water high temperature , gear box lub oil low working pressure
本船驾驶室主机仪表板设有主机冷却水温表、滑油压力表、主机转速表、主机应急停车按钮，并具有主机滑油压力低、冷却水高温、齿轮箱滑油工作压力低的声光报警装置。