1, the direct calibration method is to mark the nominal value of resistance directly on the resistor body with numbers and text symbols, the allowable deviation is expressed in percentage, and the unlabeled deviation is plus or minus 20%.
2. Digital labeling method is mainly used for small volume circuits such as patches. Among the three numbers, the first number is from left to right, the second number represents the effective number, and the third number represents the power of 10 or is represented by R; Generally, the resistance accuracy of three-digit mark is 5%, and that of four-digit mark is 1%.
For example, 472 means 47× 10 2ω (that is, 4.7 ω); 104 means 100 kω,; R22 represents 0.22ω,122 =1200 ω =1.2kω.
1402 = 14000ω= 14Kω、R220 = 0.22、50C = 324 * 100 = 32.4kω、8R20 = 8.2Ω
3. Color ring labeling is the most widely used method. The common color ring resistance is represented by 4 rings, and the precision resistance is represented by 5 rings. The color ring near one end of the resistor is the first ring, and the other end with more natural colors of the resistor is the last ring.