Design of weak current measurement system and research on temperature impact

Abstract

A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization chamber. This system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement results. Testing conducted under normal temperature conditions has demonstrated the system’s high precision performance. However, it was observed that temperature variations can affect the measurement performance. Data were collected across temperatures ranging from \(-20\) to \(70\;{^\circ }{\text{C}}\), and a temperature correction model was established through linear regression fitting to address this issue. The feasibility of the temperature correction model was confirmed at temperatures of \(-5\) and \({40}\;{^\circ }{\text{C}}\), where relative errors remained below 0.1\(\%\) after applying the temperature correction. The research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision, making it particularly suitable for measuring weak currents.