The HP/Agilent 4260A Universal Bridge is a precision impedance measurement instrument for characterizing resistors, capacitors, and inductors across wide value ranges. It delivers four-digit resolution for R, L, and C measurements, with simultaneous Q and D factor determination via analog dial display. Five selectable bridge circuits and auto-balance circuitry streamline nulling and minimize measurement time, particularly for low-Q or high-D components. The instrument operates at an internal frequency of 1 kHz or accepts external oscillators from 20 Hz to 20 kHz for component analysis across extended frequency ranges.
Technical Specifications
Measurement Ranges:
• Resistance: 10 mΩ to 10 MΩ (7 ranges)
• Capacitance: 1 pF to 1000 µF (7 ranges)
• Inductance: 1 µH to 1000 H (7 ranges)
• Dissipation Factor (D): 0.001–0.12 (low D, series C) and 0.05–50 (high D, parallel C)
• Quality Factor (Q): 0.05–1000
Measurement Accuracy:
• Resistance: ±(1% + 1 Digit) from 10 Ω to 1 MΩ; ±(2% + 1 Digit) for 10 mΩ–10 Ω and 1 MΩ–10 MΩ
• Capacitance: ±(1% + 1 Digit) from 1 nF to 100 µF; ±(2% + 1 Digit) for 1 pF to 1000 µF
• Dissipation Factor: ±(5% + 0.002) or one dial division (low D); ±(5% + 0.05) or one dial division (high D, for C > 100 pF)
Operating Frequency:
• Internal oscillator: 1 kHz
• External oscillator: 20 Hz to 20 kHz
Display & Readout:
• Four-digit digital counter for R, L, C values
• Analog dial with hairline indicator for Q and D
• Illuminated pointers indicate null direction
Bridge Residuals:
• Residual resistance: ~3 mΩ
• Residual capacitance: ~2 pF
– Key Features
• Auto-balance circuitry reduces nulling time and operator interaction
• Five bridge circuit configurations via FUNCTION switch selection
• Internal tuned amplifier detector at 1 kHz; operates as preamplifier with external generator
• Battery biasing capability via rear terminals
– Typical Applications
Component characterization in manufacturing QC, R&D laboratories, and field service environments where precise impedance and loss-factor measurements are required.
– Compatibility & Integration
External oscillator input enables impedance measurements from 20 Hz to 20 kHz, extending measurement capability beyond the 1 kHz internal frequency. Rear-panel terminals support DC biasing of test components.
