| 摘要 |
<p>A measuring instrument comprises a portable case (45) housing a drum (11) on which is wound a flexible mesuring line or tape (10) which runs over a rotary capstan (15) provided with teeth (16) engaged by a sensor (24) acting as a pulse generator to an electronic counter (27). In addition there is a direction sensor (21) arranged to provide a count-up or count-down signal and a further direct measuring wheel (30) as teeth (32) acting as a pulse generator to the same counter (27).</p> |
