When the Agilent E4980A Precision Impedance Analyzer has measurement deviations beyond tolerance, the following calibration operations need to be re-performed during maintenance: 1. Open/Short Calibration: This eliminates parasitic effects (such as stray capacitance from open circuits, series resistance/inductance from short circuits) introduced by test fixtures or connecting cables, which is a basic step to ensure measurement accuracy. 2. Load Calibration (as required): Using a standard impedance component with known parameters for calibration can further improve measurement accuracy, especially for specific impedance ranges or high-precision scenarios. 3. Cable Extension Compensation: If extended test cables (1/2/4m as supported by the instrument) are used, this calibration corrects signal loss and phase shift caused by the cables. For users who face difficulties in performing these calibrations independently or if deviations persist after calibration, Jiangxi Biology (匠析生物) can provide professional solutions. Our company specializes in comprehensive services including repair, maintenance, and calibration for lab instruments like Agilent E4980A, covering brands such as Thermofisher, Waters, GE, Cytiva, Beckman, etc. We also offer related consumables, spare parts, and application consulting services to ensure stable and accurate operation of your lab instruments.