How to test whether the shunt resistor is qualified?

DiversionresistanceAs an important component in electronic circuits, it is mainly used for current detection and current shunting. Its performance directly affects the stability of the circuit and the accuracy of measurement. Therefore, correctly testing the shunt resistor is crucial to ensure the normal operation of electronic equipment. This article will introduce in detail how to scientifically and effectively test the qualification of shunt resistors from multiple aspects.

Before testing, the rated resistance, power and allowable error range of the shunt resistor must first be clarified. Usually the rated resistance of the shunt resistor is small, the power is large, and the error range is strict. Understanding these parameters will help make accurate judgments in subsequent tests.

The most common test method is to use a digital multimeter to directly measure the resistance of the shunt resistor. Adjust the multimeter to the resistance setting, touch the probes to both ends of the shunt resistor, and read the displayed resistance. The measured value should be within the error range of the rated resistance. If the deviation is too large, it means that the shunt resistor is unqualified.

The shunt resistor will generate heat when it works. Excessive temperature rise may cause the resistance value to change or even be damaged. Through the power-on test, use an infrared thermometer or thermocouple to measure the surface temperature to determine whether the temperature rise is within the design range. Abnormal temperature rise indicates that the shunt resistor may have quality problems.

Apply the corresponding current to the shunt resistor according to the rated power and observe whether it can work stably for a period of time. If the resistance of the resistor drifts or is damaged under rated power, it means that its power bearing capacity is insufficient and does not meet the requirements.

The solder joints and connecting wires of the shunt resistor also affect its performance. Through visual inspection and tensile testing, ensure that the solder joints are firm and there are no weak solders, and the connecting wires are not broken or have poor contact, to avoid test errors caused by external factors.

For precision shunt resistors, bridge circuit measurement methods such as Wheatstone bridge can be used to obtain higher-precision resistance data and ensure the reliability of test results.

During the test, the ambient temperature and humidity should be kept stable to avoid external interference from affecting the test results. It is recommended to conduct testing in a constant temperature and humidity laboratory.

Record all test data in detail and analyze its qualification in conjunction with equipment specifications. Taking the average value through multiple tests eliminates accidental errors and improves the accuracy of judgment.

Testing whether the shunt resistor is qualified requires comprehensive consideration of many factors such as resistance value, power endurance, temperature rise, welding quality, etc. A combination of multiple methods such as digital multimeter resistance measurement, power testing, temperature rise measurement and bridge circuit are used to ensure that the test results are accurate and reliable. At the same time, a good testing environment and detailed data analysis are also important aspects to ensure the quality of shunt resistors. Only through scientific and standardized testing procedures can we effectively screen out shunt resistors that meet the requirements and ensure the normal and stable operation of electronic equipment.