RESISTANCE METER RM3545A-1

High precision DC resistance meter, 13 ranges from 1 mΩ to 1200 MΩ, basic accuracy 0.045%, 1 nΩ resolution, 6 1/2 digit display, compatible with SW1001 / SW1002 Multiplexer Systems, remote controllable via LAN, RS-232C, USB

-Resistance ranges: 1 mΩ to 1200 MΩ (13 ranges)
-Basic accuracy: 0.045% rdg ± 0.010% full scale (1 mΩ range)
-Resolution: 1 nΩ (1 mΩ range)
-Measurement time: 2.3 ms (10 Ω range, fast mode)
-Compatible with HIOKI SW1001 / SW1002 Multiplexer Systems
Applications
-Verifying busbar and weld joint resistance in battery modules
-Measuring winding resistance in motors and transformers
-Testing connection quality of EV charging connectors
-Pattern resistance measurement on printed circuit boards
-DC resistance evaluation of high-current components
Product Description
The RM3545A-1 Resistance Meter enables high-precision DC resistance measurements on components and assemblies in which even very small resistance variations can affect performance or safety. It offers 13 resistance ranges from 1 mΩ to 1200 MΩ and a maximum test current of 1 A, providing stable and accurate results for a wide range of components. With a 6 1/2 digit display, 1 nΩ resolution and a basic accuracy of ±0.045 % rdg ± 0.010 % full scale, the RM3545A-1 delivers immediate, high-precision measurements without warm-up or manual zero adjustment. Measurement times as short as 2.3 ms support high-throughput testing and short cycle times, which is particularly advantageous when the instrument is integrated into automated test systems or production lines.
The instrument is suitable for production and inspection environments as well as for use in laboratories. It is used for verifying busbar and weld joint resistance in battery modules, measuring winding resistance in motors and transformers, checking connection quality of EV charging systems, evaluating pattern resistance on printed circuit boards and measuring DC resistance of high-current components such as fuses or shunt resistors. The contact check function verifies proper probe contact, reducing errors caused by poor connections.
Advanced precision functions
To ensure consistent measurement results under fluctuating temperature conditions, the RM3545A-1 includes a Temperature Compensation (TC) function that automatically references measured values to a specified reference temperature. This function corrects the influence of material characteristics such as the temperature coefficient of copper conductors, which is approximately 0.4 % per °C and causes resistance values to vary with temperature. Temperature can be measured using the included Z2001 sensor or a compatible external thermometer with analog output. This correction ensures consistent evaluation criteria between production and final inspection and enables precise quality control, for example when measuring winding resistance.
When temperature differences occur at junctions between different metals, such as measurement leads, probes and the device under test (DUT), thermoelectric voltages are generated. These voltages can distort low-resistance readings. Since temperature differences cannot be completely eliminated, the Offset Voltage Compensation (OVC) function improves stability by applying current in both directions and averaging the results.
System integration and communication interfaces
The RM3545A-1 offers a complete set of interfaces for integration into automated test systems and production environments. Standard connectivity includes LAN, USB and RS-232C for direct communication with PCs and controllers, while the EXT I/O port allows external triggering and pass/fail control. A D/A output (0 V to 1.5 V DC) provides analog voltage output for monitoring or control purposes. The command-monitor function displays communication commands and responses at the bottom of the instrument’s display, simplifying debugging during system integration and reducing setup time.
When combined with the SW1002 Multiplexer System, the RM3545A-1 can be expanded to up to 132 channels and enables automated series measurements on multiple DUTs or measurement points after a single setup. Alternatively, the RM3545A-2 offers integrated multiplexer capability and can be fitted with up to two Z3003 Multiplexer Units, enabling measurement of up to 20 DUTs in 4-wire mode within a single instrument.