| 摘要 |
<p>The plug has a body (1) on which is mounted a cylindrical support (5) having a top plate (9). A measuring ring (7) is mounted between the top plate (9) and a tubular distance sleeve (11). The measuring ring (5) has a slightly larger internal diameter then the support (5) and thus has a small amount of lateral play. Gas under pressure is supplied (20) to two tubes (13.1, 13.2) in the measuring ring (7) and these feed four nozzles (27) which self centre the measuring ring (7) in the pipe being measured. A separate source of gas pressure with manometer is connected (20) to a third tube (14.3) in the measuring ring which supplies the pipe measurement nozzles (21).</p> |
