ABSTRACT
An ideal fixed resistor is an electronic component, the resistance value of which is constant with time and different environmental conditions. In practice, we can observe some changes of resistance in time and under high temperature, high humidity, frequency, and electrical load conditions, and so on. Those changes of a resistance, called the instability of resistor, are the basis for classification of resistors according to the requirements of the International Electrical Commission (IEC) and the International Organization for Standardization (ISO 9000-9004) in order to build in a reliability system.
