| 摘要 |
<p>Disclosed is an electromagnetic-force-balancing-type electronic balance having a magnetic circuit which includes a yoke (4), a first permanent magnet (1), a pole piece (3), a second permanent magnet (2) and a cover (5). A connection member (7) made of a magnetic material is disposed in an air-gap region included in the magnetic circuit. The connection member (7) may be disposed between the second permanent magnet (2) and the cover (5) or between the cover (5) and the yoke (4) to facilitate assembling operations. Alternatively, first and second gap-defining members (8), (9) made of a non-magnetic material may be disposed, respectively, between the first permanent magnet (1) and the yoke (4) and between the second permanent magnet (2) and the cover (5), to provide symmetric properties in magnetic sub-circuits so as to counteract an imbalance in hysteresis characteristic. The present invention can suppress adverse influences of a magnetic resistance caused by an air gap existing in the magnetic circuit of the electronic balance.</p> |
