1. Straight-marking method: The resistance value is marked on the surface of the resistor by the number and unit symbol, and the allowable error is directly expressed by the percentage. If the resistance is not marked, the deviation is ±20%.
2. Text symbol method: The regular resistance is represented by a regular combination of Arabic numerals and text symbols, and the allowable deviation is also represented by a text symbol. The number before the symbol indicates the integer resistance, and the following numbers represent the first decimal resistance and the second decimal resistance. The text symbol text symbol indicating the allowable error: DFGJKM allowable deviation is: ±0.5%±1%±2%±5%±10%±20%.
3. Digital method: A three-digit digital representation of the nominal value on the resistor. From left to right, the first and second digits are valid values, and the third digit is the index, which is the number of zeros. The unit is Europe. Deviations are usually indicated by text symbols.
4. Color-code method: Mark the nominal resistance and allowable deviation on the surface of the resistor with different colored bands or points. Most of the foreign resistors use the color standard method.
Black-0, Brown-1, Red-2, Orange-3, Yellow-4, Green-5, Blue-6, Purple-7, Gray-8, White-9, Gold-±5%, Silver-±10 %, colorless - ± 20%
When the resistance is four-ring, the last ring must be gold or silver, the first two digits are significant digits, the third digit is the power square, and the fourth digit is the deviation.
When the resistance is five rings, the distance between the last ring and the front four rings is larger. The first three digits are significant digits, the fourth digit is the power square, and the fifth digit is the deviation.