Secondary Instruments

Definition:
They are defined as the instruments that give a ready measure of the quantities with the help of graduated scales.

• The value of the electrical quantity to be measured is determined from the deflection of these instruments.
• With an absolute instrument these instruments are calibrated. ie, the secondary instruments are compared with known standards or absolute instruments.
• All the electrical measuring instruments belong to this category.

There are three categories of secondary instruments.
1. Indicating instruments
2. Recording instruments

Definition:
They are defined as the instruments that give a ready measure of the quantities with the help of graduated scales.

• The value of the electrical quantity to be measured is determined from the deflection of these instruments.
• With an absolute instrument these instruments are calibrated. ie, the secondary instruments are compared with known standards or absolute instruments.
• All the electrical measuring instruments belong to this category.

There are three categories of secondary instruments.
1. Indicating instruments
2. Recording instruments
3. Integrating instruments

These are instruments whose output is measured to give the value of the quantity. The quantity to be measured is determined by the deflection value of these instruments.

These instruments need to be calibrated against an absolute instrument.

Examples – ammeter, voltmeter, ampere-hour meter, wattmeter etc.

Absolute instruments are used in laboratories as standardizing instruments, whereas secondary instruments are used in everyday work.

Almost all Instruments in General use such as ammeter, voltmeter, ampere-hour meter, wattmeter, power factor meter, frequency meter etc. belong to this class.

Read more:

1. Definitions Used in Electrical Measuring Instruments
2. Absolute Instruments
3. Secondary Instruments
4. Integrating Instruments
5. Recording Instruments
6. Indicating Instruments