Definition of Indicating, Intergrating and Recording Instruments

Indicating, Intergrating and Recording Instruments

Measuring instruments (i.e. secondary instruments) may be classified according to their function as:

1.       Indicating instruments

2.       Integrating instruments

3.       Recording instruments

1.       Indicating instruments: “Indicating instruments are those which indicate the magnitude of an electrical quantity at the time when it is being measured.”

Their indications are given by a pointer moving over calibrated dial.

Example: Ordinary voltmeters, ammeters and wattmeter’s, etc.

2.       Integrating instruments: “Integrating instruments are those which measure and register by a set of dials and pointer either the total quantity of electricity (In amp-hours) or the total amount of electrical energy (in watt-hours or kWh) supplied to a circuit in a given time.”

Example: The ampere-hour meters and energy (watt-hour) meters

3.       Recording instruments: “Recording instruments are those which give a continuous record of the variation of the electrical quantity over a selected period of time.”

The moving system of the instruments carries an inked pen which rests lightly on a chart or graph, wrapped over a drum moving with a slow uniform speed. The motion of the drum is in a direction perpendicular to that of the pointer. The path traced out by the pen indicates of the electrical quantity.

Example: Recording voltmeter and ammeter.

Uses: These instruments are generally used in supply stations (i.e. power houses) where continuous information is required.