HIOKI RM3548-50 Resistance Meter | 0.1 µΩ–3.5 MΩ, max. test current 1 A DC, four-terminal + OVC, automatic temperature correction, optional Z3210 Bluetooth

HIOKI RM3548-50 Resistance Meter: Portable Low-Resistance Measurement with 0.1 µΩ Resolution

Overview

The RM3548-50 measures low resistance with the four-terminal method, with a finest resolution of 0.1 µΩ and a maximum test current of 1 A DC; OVC (offset voltage compensation) reduces the effect of thermal EMF. It is used to measure the resistance of motor windings, busbars, welds and contacts. The RM3548-50 is the successor to the RM3548 (discontinued).

Key Specifications

• Measuring range: 0.1 µΩ–3.5 MΩ (0.1 µΩ resolution on the 3 mΩ range).
• Accuracy: ±0.020% rdg. ±0.007% f.s.
• Test current: 1 A DC (3 mΩ range) to 500 nA DC (3 MΩ range).
• Temperature correction: Automatic temperature correction with temperature sensor Z2002.
• Protection: Automatic overvoltage protection if connected to a live conductor by mistake; withstands 60 V DC.
• Power and weight: LR6 alkaline or Ni-MH rechargeable batteries ×8, approx. 10 h continuous use; approx. 890 g including batteries and protector.
• Wireless: Bluetooth transfer with the optional Z3210.

Applications

• DC winding resistance measurement of motors and transformers.
• Contact resistance checks of battery module busbars, copper bars and welds.

Specifications per the HIOKI product page and RM3548-50 press release (retrieved 2026-10-20).