Analysis Why is the resistor stability more important than accuracy?
Precision resistors are typically associated with high precision resistors. Accuracy represents the accuracy of resistance resistance. In fact, this accuracy is affected by many factors. These factors affecting the accuracy of the resistance are collectively referred to as "pressure". Pressure comes from many aspects, such as changes in ambient temperature, self-heating, PCB pressure or tension, moisture, or even corrosive gases such as welding, pulse, overload, static electricity.
All "stress" mentioned will change the resistance of the resistor, that is, the resistance accuracy of the resistor is affected. So what kind of resistance is a precision resistor? The answer is the resistance of stability and accuracy.
The resistance of the resistor is affected by various "stress", and the high precision of maintaining stability is meaningful. For example, the accuracy of the resistor is ± 0.01% at the time of the factory. We have paid expensive costs for this, but after storage for several months or hundreds of hours, the resistor may change more than ± 300ppm or more. Another most common case is that the resistor is in the nominal accuracy range when entering the detection, and the nominal precision range is exceeded after welding to the PCB. Moreover, such as moisture, static electricity, etc. will cause changes in the resistance of the resistor. First, stability should be considered, rather than the high precision of the side.