directional arrow中文什么意思

指向天线

• directional:    adj. 1.方向的。 2.【无线电 ...
• arrow:    n. 1.矢，箭。 2.箭状物，箭头 ...
• the arrow:    北天的小星座

例句与用法

1. Directional arrow to indicate the direction of the pedestrian crossing
   震动器有一个箭咀指示行人过路线的方向
2. Chlorine service ? valves can be provided to meet all specifications listed by the chlorine institute pamphlet no . 6 , including the provision of a vented ball , a flow directional arrow , and are cleaned and bagged to prevent contamination
   氯气应用-可提供能够满足氯气协会第6小册子所列的全部标准和规定的阀门，包括通风球的预备，流向箭头，以及为了防止污染而进行的清洗和包装。
3. Bleach ball valves must be permanently marked externally with : the word bleach ; two opposing directional arrows , one inscribed with flow and the other with vent ; and nsf ( symbol of the national sanitation foundation international , indicating approval for use with potable water )
   漂白剂球阀必须在外部永久性标志：漂白剂；两个反向箭头，一个标志流向，另一个标志排出孔；以及nsf (美国全国卫生设备基金会国际的标记，表示已认证可用于饮用水) 。

百科释义

Directional arrows is a type of traffic sign directing people to points of interest such as commuter rail stations, colleges, tourist attractions, neighboring communities and the like.