Electrical Comparator

 Electrical Comparator

The electrical comparator works on the principle that the mechanical displacement is converted into an electric signal. Hence they are known as an electro-mechanical measuring system.

The block diagram shows the electromechanical measuring system.

The vertical movements of the plunger are transmitted to an armature, which is suspended, on thin metal strips. At the left-hand side of the armature, we observe that armature lies between two electromagnetic coils A and B, which form two arms of an A.C. bridge circuit.

The movement of the armature between the two electromagnetic coils sets up out of balance effects, which are recorded by a micrometer. If micro-ammeter is calibrated in terms of the displacement of the plunger, direct reading of small movements can be achieved.

Advantages of Electrical Comparator:

Vibrations are reduced due to least weight of mechanical.

It consists of less moving parts.

By AC supply the friction errors are reduced.

For measuring units the indicating instrument can be held at remote locations.

Disadvantages of Electrical Comparator:

The accuracy of this Comparator is affected by supplying of variations in AC current.

Heating of coils may lead to the occurrence of zero drift.

It is more expensive.

Pointer moving over a fixed scale reduces the range of Comparator.

USE OF ELECTRICAL COMPARATOR:

It is used for measuring head.

It is used indication panel, to prove visual indicators.

It is used for external gauging, internal gauging, and thickness gauging.

It is used for measuring flatness measurement.