As one of the most fundamental components in electronic circuits, resistors' performance directly impacts circuit stability and reliability. Therefore, standardized resistor testing is crucial for ensuring circuit quality. The following is a standard resistor testing process.
First, a visual inspection is the first step. Visually inspect the resistor for broken leads, damaged casing, burn marks, or blurred markings. Any obvious physical damage will result in a failure.
Second, resistance measurement is crucial. Using a digital or analog multimeter in the resistance setting, touch the test leads to each lead of the resistor. Before measuring, ensure the multimeter is functioning properly and select the appropriate range (auto-ranging mode is preferred). For fixed resistors, the measured resistance should match the nominal value, typically within a tolerance of ±5% (±1% for precision resistors). Any value outside this tolerance is considered defective. For variable resistors (such as potentiometers), it's also necessary to check whether the resistance change at the wiper is continuous and smooth, and to verify that the resistance across both ends meets the nominal total resistance.
Finally, power-on testing is applicable in specific scenarios. When power is applied to the circuit board, the voltage drop under operating conditions can be measured and, using Ohm's law, the actual resistance can be inferred to determine whether the resistor is malfunctioning due to overheating, aging, or poor contact.
After testing, the resistance data should be recorded and any defective products should be marked. For resistors in high-precision or critical circuits, a more specialized LCR meter is recommended for high-frequency characteristic analysis. A standardized testing process can effectively screen out faulty components and ensure the long-term stable operation of electronic equipment.