| 摘要 |
<p>PURPOSE:To provide an ammeter which enables the measuring of a current value of an intended electric wire with limited error even when a conductor with a current flowing therethrough approaches in the vicinity of the ammeter. CONSTITUTION:Channel-shaped shield members 2 and 3 are arranged respectively outside coils M1 and M2 wound on both arm parts of a core 1 having a U-shaped magnetic circuit to shield the magnetic effect from outside while coils DELTAM1 and DELTAM2 for correction of an air core are arranged additionally outside the shield members 2 and 3. All the coils are connected in series. The connection polarity is corrected by a connection made so that a voltage to be induced in the coils DELTAM1 and DELTA2 with an external conductor 5 excluded from the conductors to be measured is subtracted from an addition of a voltage induced in the coils M1 and M2 with a primary conductor 4 to be measured and a voltage induced in the coils M1 and M2 with the external conductor 5 excluded from those to be measured. By converting an output voltage value into a current value, this enables the measuring of the current value with limited error.</p> |
