How to measure high-precision current detection resistance

The key to achieving high-precision measurement of current detection resistors lies in the comprehensive consideration and optimization of multiple aspects. The following are the main methods for achieving high-precision measurement:

1. Choose high-precision resistors
Low resistance, high precision: Choosing low resistance, high-precision resistors as current detection resistors can reduce the impact of resistors on the overall resistance of the circuit while ensuring measurement accuracy.
Good stability: Choose resistors with low temperature coefficient and good stability to ensure consistent measurement accuracy under different temperature and humidity conditions.
2. Optimize circuit design
Reduce parasitic resistance and inductance: In circuit design, the influence of parasitic resistance and inductance should be minimized as much as possible to improve measurement accuracy. This can be achieved through optimizing wiring, selecting appropriate connectors and plugs, and other methods.
Adopting differential measurement technology: Differential measurement technology can eliminate common mode noise and drift, and improve measurement accuracy. In the current detection circuit, a differential amplifier can be used to read the voltage drop across the current detection resistor, thereby achieving differential measurement.
3. Accurate calibration and compensation
Calibration resistor: Accurately calibrate the current detection resistor before use to ensure that its resistance value is consistent with the nominal value. This can be accomplished through professional calibration equipment or standard resistors.
Temperature compensation: As the resistance of the resistor varies with temperature, temperature compensation is required to improve measurement accuracy. This can be achieved by adding temperature sensors and compensation circuits to the circuit.
4. Improve signal processing capability
Using high-precision ADC: Using a high-precision analog-to-digital converter (ADC) to convert analog voltage signals into digital signals to improve measurement resolution and accuracy.
Digital filtering and calibration: Filtering and calibrating measurement data in the digital domain to eliminate noise and errors, and improve measurement accuracy and stability.
5. Pay attention to the installation and heat dissipation of resistors
Reasonable installation: Ensure that the installation position of the current detection resistor is reasonable, avoiding the influence of mechanical or thermal stress.
Good heat dissipation: Due to the heat generated by the current detection resistor during operation, it is necessary to ensure good heat dissipation conditions to avoid overheating of the resistor and affecting measurement accuracy.
In summary, achieving high-precision measurement of current detection resistors requires comprehensive consideration and optimization from multiple aspects such as resistor selection, circuit design, calibration and compensation, signal processing, installation, and heat dissipation. By taking these measures, the accuracy of current detection can be significantly improved, meeting the needs of various high-precision applications.