High-precision resistance measurement: key technologies and methods to improve measurement accuracy

Electronic engineering and scientific research fields,resistanceMeasurement is one of the basic and critical testing items. With the development of technology, especially in the manufacturing process of high-precision electronic equipment and instruments, higher requirements have been placed on the accuracy and stability of resistance measurement. High-precision resistance measurement not only ensures product quality, but also improves the overall performance of the system. Therefore, it is crucial for engineers and technicians to understand the core technologies and methods of high-precision resistance measurement. This article will systematically introduce the key contents of high-precision resistance measurement to help readers gain an in-depth understanding of relevant knowledge.

High-precision resistance measurement mainly relies on accurately measuring the voltage and current across the resistor and calculating the resistance value through Ohm's law. In order to ensure measurement accuracy, measuring instruments and methods must minimize external interference and measurement errors. Commonly used measurement methods include the four-wire measurement method and the Wheatstone bridge method. These methods can effectively eliminate the influence of wire resistance and contact resistance and improve the reliability of measurement.

The four-wire measurement method uses two wires to supply power and the other two wires to measure voltage, which avoids the influence of wire resistance on the measurement results. Compared with the traditional two-wire measurement method, the four-wire method performs well in micro-ohm level or even nano-ohm level resistance measurement, and is widely used in the testing of high-precision resistance and low-resistance materials. This method can significantly reduce errors caused by poor leads and contacts, and is one of the basic technologies for achieving high-precision measurement.

The Wheatstone bridge is a classic resistance measurement circuit that measures unknown resistance by balancing the bridge circuit. Using the balance point of the bridge, measurement errors can be reduced to extremely low levels. The modern digital Wheatstone bridge combines automatic adjustment and digital display functions to further improve the convenience and accuracy of measurements. This method is suitable for high-precision and repeatable measurement of resistance in laboratories and production lines.

The resistance value changes with temperature, and the temperature coefficient is one of the main factors affecting measurement accuracy. Constant temperature environment or temperature compensation technology is often used in high-precision measurements to ensure temperature stability during measurement or to correct errors caused by temperature through algorithms. In addition, using resistors made of low-temperature drift materials can also help reduce the impact of temperature on measurement results.

High-precision resistance measurement requires high-performance instrument support, such as high-precision digital multimeters, microohmmeters and special resistance measuring instruments. The resolution, stability, noise level and calibration status of the instrument will directly affect the measurement results. Calibrating and maintaining the instrument regularly to ensure that its performance indicators meet the measurement requirements is the key to ensuring measurement accuracy.

Environmental factors such as electromagnetic interference, vibration and humidity can adversely affect resistance measurements. Using shielding measures, good grounding and anti-interference design can effectively reduce environmental noise. Optimization of the laboratory environment, such as constant temperature and humidity and anti-vibration tables, can also help improve the stability and repeatability of measurements.

High-precision measurement requires not only data acquisition, but also scientific processing and error analysis of measurement data. Using statistical methods to analyze the average and deviation of multiple measurement results can accurately evaluate the uncertainty of measurement. In addition, establishing error models and adopting correction algorithms can further improve the reliability of measurements.

High-precision resistance measurement is an important topic in the field of electronic testing, involving many aspects such as measurement principles, instrument selection, environmental control, and data analysis. By using the four-wire measurement method and Wheatstone bridge technology, combined with temperature control and anti-interference measures, the accuracy and stability of resistance measurement can be significantly improved. Scientific and reasonable data processing and error analysis also provide guarantee for achieving high-precision measurement. Mastering these core technologies will help engineers ensure the high quality and reliability of resistance measurement during the R&D and production processes, and promote the continuous progress of electronic technology.