Error and fault tolerance of precision chip resistors

What is the precision chip resistor? Is that the error precision chip resistor SMD resistor is relatively small is generally called the error of 1% chip resistors, the minimum error (accuracy) can reach 0.01% DEG C to + 5ppm/ low temperature coefficient, the industry is rarely done: it can be used in precision instruments, communications electronics and portable electronic products.
So, a lot of people would ask, chip resistance is so small, if not tested 5% and 1% can distinguish it?
Good question, so what are the differences between the 5% and 1% patch resistors?.
The 5% series resistor with 3 digit said: This represents a valid digital representation method the resistance value of the top two, third digit number in the numbers behind should add "0". When the resistance is less than 10, with R said in the code the resistance value of the decimal point position, this kind of representation law is often resistance error of 5% resistance in the series. For example: 330 said 33, rather than 330 ohm; 221 220 ohm; 683 said that 68000 68K; 105 1M 6R2 said; 6.2.
The 1% series of precision SMD resistors are represented by 4 digit numbers: the first 3 digits of this representation represent the effective numbers of the resistance values, and the fourth bits indicate the number of 0 to be added after the valid number. When the resistance is less than 10, the code is still represented by R resistance value of the decimal point position, this method has general resistance error of 1% precision resistor series. For example: 0100 said 10 instead of 100; 1000 said 100 instead of 1000; 4992 said that 49900, 49.9k; 1473 said that 147k 0R56 147000 Omega Omega 0.56 Omega said.
SMD resistors are engraved on the surface of the letter, if only three digits, then the error is 5%, and if there are 4 digits, then it is 1% of the error.