An indicating instrument is commonly fitted with a pointer that indicates on a scale the value of the quantity.一个显示仪器通常装有一个指针,表明规模数量的值。

Owing to the delicate nature of the moving system ,this type of instrument is only suitable for measuring currents up to about 50mA directly.

由于移动系统的微妙性质，这种类型的仪器是只适合测量电流50毫安直接的。

The work on the principe of a mechanical force causing operation of a relay contact in response to a stimulus.

The mechanical force is generated through current flow in one or more windings on a magnetic core or cores ,hence the term electromechanical relay.

机械力造成的刺激继电器触点的操作原则的工作。在一个或多个绕组对磁芯或核心，因此，长期的机电式继电器通过电流流动产生的机械力。

Movement of the armature causes contact closure or opening ,the armature either carrying a moving contact that engages with a fixed one ,or causes a rod to move that brings two contacts 一杆移动，使两个接触在一起。

The term 'static ' implies that the relay has no moving parts.

This is not strictly the case for a static relay ,as the output contacts are still generally attracted armature relays.

In a protection relay,the term 'static' refers to the absence of moving parts to create the relay characteristic .Introduction of static relays began in the early 1960's.

静'意味着该继电器具有无运动部件。

这是不严格的情况下，静态继电器输出触点一般仍然吸引电枢继电器。

在保护继电器，长期“静态”是指没有运动部件的创建继电器特性。静态继电器的介绍，在1960年初开始。

Their design is based on the use of analogue electronic devices instead of coils and magnets to create the relay characteristic.其设计的基础上，而不是创建继电器特性的线圈和磁铁的模拟电子设备的使用。

Microprocessors and micro-controllers replaced analogue circuits used in static relays to implement relay functions.微处理器和微控制器取代模拟电路在静态继电器用于实现中继功能。

The distinction between digital and numerical relay resets on points of fine technical detail,and is rarely found in areas other than protection.

The distinction between digital and numerical relay resets on points of fine technical detail,and is rarely found in areas other than protection.

They can be viewed as natural developments of digital relays as a result of advances in technology.

Typically .they use a specialised digital signal processor as the computational hardware,together with the associated software tools.

区分数字和数字中继复位精细的技术细节点，比保护以外的其他地区很少发现。作为技