| 摘要 |
A handy type curve length measuring apparatus comprises a pen-holder like body (1), a castor (3) rotatably connected with the body so as to rotate around rotation axis (c) and having a disk (2) including slits (s), pulse generating means (7) and an indicator (6). When the disk (2) rolls on a curved line, the slits (s) provided on the disk move past a pulse generating means (7). Counting means (10) count the number of pulses and the indicator (6) displays the length of the curve based on the number of generated pulses. Since the apparatus can trace curved lines without rotating the body due to the castor mechanism, an accurate and easy measurement of length can be attained.
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