In electrical circuits, we use many resistances. You will see four or five ring printed on them. Despite of using multimeter, you have another choice to judge it. You can read the color of each ring and get the exact resistance.
Each color, in these rings, stands a number. Here is a table show their relation:
There are also two special color stands for measurement error. Gold stands a measurement error about ±5％ and silvery for ±10％. Some times, other colors like brown or green can also show the measurement error when the printed on the last ring. Brown for ±1％ red for ±0.2％ and green ±0.5%. www.zhangpeng.info
There are two kinds of resistance: resistance with four rings and resistance with five rings. The rings stands for the similar meaning. The key to judge a resistance is to identify the sequence of each rings. There are two ways to judge the sequence. Judge by the space between rings or distinguish the color that shows measurement error.
Judge by the distance between rings
There have a different space between rings. The last space is always longer than first step. You can carefully check your resistance.
Distinguish the color that shows measurement error first
As I told you above, gold and silvery always show a measurement error. If a resistance have a ring with color gold or silvery, it’s useful to identify the list by its special color.
On a resistance, the color ring show more details besides only numbers.
For a resistance with four rings, the first two rings show you the number. The third one tell you how many zeros behind the number.
The only difference between resistance with five rings and four rings resistance is that there are three rings show the number in the former one.
Here I give you a simple example:
You had know red for 2, purple for seven and there is just one zero behind it. So the exact resistance is 270Ω.