Resistor color coding is a system used to indicate the values or ratings of electronic components, usually for resistors, but also for capacitors, inductors, diodes, and others. The color coding of resistors is defined in the international standard IEC 60062. The purpose of resistor color codes is to indicate the resistance value, tolerance, and sometimes the reliability or failure rate of very small electronic components.
The color coding system uses colored bands to quickly identify the resistance value, tolerance, and sometimes the reliability or failure rate of a resistor. The number of bands on a resistor can vary from three to six, with the most common being four and five bands. The colors used in the coding system represent digits, multipliers, and tolerances. The table below shows the colors and their corresponding values:
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | 1 | |
| Brown | 1 | 10 | ±1% |
| Red | 2 | 100 | ±2% |
| Orange | 3 | 1,000 | |
| Yellow | 4 | 10,000 | |
| Green | 5 | 100,000 | ±0.5% |
| Blue | 6 | 1,000,000 | ±0.25% |
| Violet | 7 | 10,000,000 | ±0.1% |
| Grey | 8 | ±0.05% | |
| White | 9 | ||
| Gold | 0.1 | ±5% | |
| Silver | 0.01 | ±10% |
To read the color code, one should hold the resistor such that the tolerance band is on the right. Starting from the left, note down all the colors of the bands and write them down in sequence. Next, use the table to see which digits they represent. The first two bands represent the significant digits, the third band represents the multiplier, and the fourth band represents the tolerance.
For example, a resistor with the color bands brown, black, red, and gold would have a resistance value of 1,000 ohms with a tolerance of ±5% .
In summary, resistor color coding is a system used to indicate the values or ratings of electronic components, usually for resistors. The color coding system uses colored bands to quickly identify the resistance value, tolerance, and sometimes the reliability or failure rate of a resistor. The number of bands on a resistor can vary from three to six, with the most common being four and five bands.
