How To Read Colour Code From Resistors

How To Read Colour Code From Resistors

‌The first electronic component I first loved when getting started in electronic is the resistor. I love the resistor because of its different colours printed on it. I thought these colours were just a mere design in order to make it look nice. Actually the colours on a resistor’s body indicates it’s value.Each colour on it is a guide to know the value (number or digit) of the resistor.

The table below show the value of each colour on the resistor:

ColourSignificant FigureMultiplierToleranceTemperature Coefficient (ppm/°C)    
Black0×1+/-1%
Brown1×10+/-2%100
Red2×10050
Orange3×100015
Yellow4×10k25
Green5×100k+/-0.5%
Blue6×10M+/-0.2510
Violet7×100M+/-0.10%5
Grey8×1000M+/-0.05%
White9×1G
Gold×0.1+/-5%
Silver×0.01+/-10%
None+/-20%

Short Rules On Reading A Resistor You Should Follow

  1. Resistors whose colour bands are grouped together or close to one end should be held to the closely grouped bands to your left and read the resistor from left to right.
  2. The procedure is easy with 5% and 10% resistors, hold the resistor with the silver or gold band to the right and read the resistor from the left to the right .
  3.  The first band can’t never be silver or gold , so if you see such resistor you should know where to start the reading from. Also, the 3rd color for 4-band resistors should be blue  or less and the 4th color for 5 band resistors should be green or less, because basic resistor values range from 0.1 Ohm to 10 MegaOhms.
  4.  A 3-band resistor has a tolerance of 20%.

 

Tolerance of a resistor is the percentage of error in the resistor’s resistance, or how much more or less you can expect a resistor’s actual measured resistance to be from its stated resistance value. For instance, if the tolerance value of a 100 resistor is +\-10%(silver);it means that the actual value of resistance is in the range of 90 ohms and 110 ohms ( 100-0.1×100=90 to 100+0.1×100=110).

Temperature coefficient (TC) is the rate of resistance change based on temperature.It is oftenly expressed in ppm /°C ( parts per million per degree Centigrade) units.

Reading A 4-Band Resistor

  1. The first colour and second colour indicates the resistor’s digit.
  2. The third colour indicates the multiplier and
  3. The last colour indicates the tolerance of the resistor.

Resistor colour code

 

 

 

 

 

For example

A resistor with colours brown, black, brown and gold like the one in the above picture has a resistance of : Brown-1, Black-0, Brown-10 which is 10×10=100 ohms and with tolerance of +/-5%(gold).

 

Reading A 5-Band Resistor

  1. The first, second and third colours indicate the resistor’s digit.
  2. The fourth colour indicates the multiplier and
  3. The last colour indicates the tolerance of the resistor.

Example:

A resistor with colours brown, red, red, orange and red will have a resistive value of: Brown-1, blue-6, Red-2 , Orange-1000 which is 162,000 ohms(162 kiloohms) with tolerance of +/-2% (red).

 

Reading A 6-Band Resistor

  1. The first,second and third colours indicate the resistor’s digit.
  2. The fourth colour indicates the multiplier.
  3. The fifth colour indicates the tolerance of the resistor and
  4. The last colour indicates the temperature coefficient of the resistor.

 

Examples of resistance values

  • R47 means 0.47 ohm
  • 2R5 means 2.5 ohm
  • 250R means 250 ohm
  • 2K5 2.5 kilohm
  • 25K 25kilohm
  • 25K2 means 25.2 kilohm
  • 250K 250 kilohm
  • 2M5 means 2.5 megohm
Loading Facebook Comments ...

Leave a Reply

Your email address will not be published. Required fields are marked *