Friends, today in this article we will learn about electrical measuring instruments. I am going to give information about all these in a very good way. So let’s start.
Classification of measuring instruments –
Broadly speaking, electrical measuring instruments are divided into the following categories.
Absolute and secondary instruments –
(a) Absolute Instrument – The quantity measured by these instruments is related to their constant and deflection and their calibration and comparison with standard instruments is not necessary. Rather, standard instruments are made with the help of these. The value of the results measured by them is obtained from the product of their deflection and constant. Tangent galvanometer, Rayleigh current balance and absolute electrometer are examples of this. Calibration is not required in these instruments. These instruments are generally not used in practical.
(b) Secondary Instrument-The quantity measured by these instruments is known directly from the deflection of the instrument. These instruments are calibrated and compared with absolute or substandard instruments. Instruments of this type can also be used as absolute or absolute instruments. Voltmeter, ammeter, demand indicator, frequency meter, energy meter, power factor meter etc. are its examples.
Analog and Digital Instruments-
Analog Instruments-Analog device is a device whose output or display is a continuous function of time and maintains a constant relationship with the input. Analog instruments have many applications at present.
Analog instruments can be classified according to the quantity to be measured, for example, the instrument used to measure current can be classified as ammeter and the instrument used to measure voltage can be classified as voltmeter. Apart from this, other analog instruments are wattmeter, power factor meters, frequency meter etc.
Electrical instruments can also be classified on the basis of the type of current to be measured. For example-
(i) Direct current (D.C.) instruments
(ii) Alternating current (A.C.) instruments
(iii) Direct current and alternating current instruments, these instruments are called universal instruments.
Analog instruments depend on many effects produced by current and voltage for their operation. Therefore, they can be classified on the basis of the effect used for the functioning. Analog instruments can also be divided into the following three types-
(a) Indicating instruments
(b) Recording instruments
(c) Integrating instruments
(a) Indicating Instruments-Instruments which display the instantaneous value of electrical quantity by a pointer scale device are called indicator or indicating instruments. For example- ammeter, voltmeter etc.
(b) Recording Instruments-An ink filled pen is attached to the moving system of these instruments which continuously records the value of the measured quantity on the graph paper. For example- E.C.G. machine etc.
(c) Integrating Instruments – Integrating instruments tell the total measurement of the quantity to be measured on the dial for a given time, i.e., the complete magnitude from the beginning till that moment. For example – ampere hour meter, kilowatt hour meter, etc.
Digital Instruments –
Analog instruments show the magnitude of the quantity to be measured as the deflection of the scale. That is, in the form of analog displacement or angle relative to the electrical quantity. Digital instruments show the magnitude of the quantity to be measured in decimal number. Due to inertia, the response time in analog instruments is more, hence these instruments are not suitable for fast speed or changing systems and it also takes time to take readings from these instruments. Whereas in digital instruments, the readings are obtained directly in digits, hence there is ease in use. And there is no possibility of experimental and human errors. Power requirement for digital instruments is less.
What did you learn today:-
Now you must have known what are electrical measuring instruments and you must have got the answer to all these questions well.
I hope you liked the information given by me. If you have any question/suggestion in your mind, then you can tell me by commenting below, I will definitely answer your comment. If you liked this post, then you can also share it with your friends and relatives.