The Keysight 4328A Milliohmmeter is a precision instrument for low-resistance measurement using Kelvin Bridge methodology and four-terminal measurement technique. It delivers high sensitivity across 0.001 Ω to 100 Ω full scale with maximum resolution of 0.02 Ω, achieving ±2% accuracy. The instrument employs constant applied current with a 1000 Hz ±100 Hz measurement frequency and maintains sample voltage below 200 µV peak at full scale—never exceeding 20 mV peak under any condition, including incorrect range settings.
## Technical Specifications
• **Measurement Range:** 0.001 Ω to 100 Ω full scale in 1, 3, 10 sequence
• **Resolution:** 0.02 Ω (0–1 Ω scale); 0.05 Ω (0–3 Ω scale)
• **Accuracy:** ±2% of full scale
• **Measurement Frequency:** 1000 Hz ±100 Hz
• **Sample Voltage:** 200 µV peak at full scale; 20 mV peak maximum under all conditions
• **Series Reactance Tolerance:** Unaffected up to 2× full-scale resistance
• **Superimposed DC Bias:** Up to 150 V DC from external source
• **Applied Current:** 150 / (full scale value in mΩ)
• **Recorder Output:** 0.1 V DC at full scale; output impedance ≈1 kΩ
• **Power:** 115/230 V ±10%, 50–60 Hz, 1.5 VA
• **Dimensions:** 155 mm (H) × 130 mm (W) × 280 mm (D)
• **Weight:** 3.2 kg
## Key Features
• Four-terminal measurement eliminates lead resistance errors
• Low power dissipation enables heat-sensitive sample testing
• Automatically limited voltage for safe measurement of fuses and explosive devices
• 150 V DC bias superposition for incremental back-biased diode resistance
• Optional rechargeable battery (Option 001) supports 15 hours continuous operation
• Recorder output for integration with external logging equipment
## Typical Applications
• Contact resistance in switches, relays, connectors
• Conductor and semiconductor resistivity
• Incremental diode resistance under bias
## Compatibility & Integration
Supplied with HP 16005A clip-type probe, HP 16006A pin-type probe, HP 16007A/B test leads, and HP 16143A probe cable. Accepts external DC bias sources up to 150 V.
