每一套装置应包括一个主开关和电流表，电流表的刻度范围约20安培。

Each unit should include a main switch and ammeter with a scale of about 20 ampere capacity.

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与将多个电流信号切换至单台安培表不同，将一个电流源切换至多个负载通常不需要任何时候到维持电流通路的连续性。

Unlike switching current signals to an ammeter, switching a current source to multiple loads usually does not require maintaining the current path at all times.

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确保直流电流表指示降低大约5安培(回到初始值)。

Make sure that the dc ammeter indication decreases approximately 5 amperes (returns to its original value).

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