RM3545A-1 Resistance Meter

Detailed Product Overview

The RM3545A-1 Resistance Meter delivers high-precision DC resistance measurements for components and assemblies where even minimal resistance variations can impact performance or safety. Covering 13 resistance ranges from 1 mΩ to 1200 MΩ and offering a maximum test current of 1 A, it ensures stable, accurate readings across a wide range of applications. With a 6 ½-digit display, 1 nΩ resolution, and basic accuracy of ±0.045 % rdg ± 0.010 % full scale, the RM3545A-1 provides instant, high-precision measurements without requiring warm-up or manual zero adjustment. Fast measurement times down to 2.3 ms enable high-throughput testing and short cycle times—ideal for automated test systems and production lines.

Designed for both laboratory and production environments, the RM3545A-1 is widely used for verifying busbar and weld resistance in battery modules, measuring winding resistance in motors and transformers, checking EV charging connections, evaluating PCB pattern resistance, and testing high-current components such as fuses or shunt resistors. The built-in contact check function ensures proper probe contact and minimizes errors caused by poor connections.

Advanced Precision Functions

To maintain measurement stability under varying temperatures, the RM3545A-1 features a Temperature Compensation (TC) function that automatically references results to a specified temperature. This corrects for material temperature coefficients—such as copper’s typical 0.4 % per °C—ensuring consistent evaluation criteria between production and final inspection. Temperature can be measured with the included Z2001 sensor or any compatible analog-output thermometer, enabling precise quality control, for example when measuring winding resistance.

Temperature differences at junctions between dissimilar metals (such as probes, leads, and DUT terminals) can generate thermoelectric voltages that distort low-resistance readings. The Offset Voltage Compensation (OVC) function improves stability by applying current in both directions and averaging the results, effectively reducing these thermal EMF effects.

System Integration and Communication Interfaces

The RM3545A-1 offers comprehensive connectivity for integration into automated systems. Standard interfaces include LAN, USB, and RS-232C for direct communication with PCs and controllers, plus an EXT I/O port for external triggering and pass/fail control. A D/A output (0 – 1.5 V DC) provides analog voltage for monitoring or control. The command-monitor function conveniently displays communication commands and responses on the instrument’s screen, streamlining debugging and reducing setup time.

When combined with the SW1002 Multiplexer System, the RM3545A-1 expands to up to 132 channels, enabling automated series measurements across multiple DUTs or test points after a single setup. Alternatively, the RM3545A-2model integrates multiplexer functionality and supports up to two Z3003 Multiplexer Units, allowing measurements of up to 20 DUTs in 4-wire mode within a single instrument.