The HIOKI RM3545 and RM3544 are bench-top resistance meters that measure resistance using the 4-terminal direct-current (constant-current) method with a guard terminal. The RM3545 is positioned as a super-high-accuracy, multi-channel instrument for advanced development and production applications, while the RM3544 is a high-accuracy bench-top meter suited to both manual operation and integration with automatic lines. Both are described as high-accuracy bench-top meters ideal for production lines.

Listed measurement targets span motors, solenoids, choke coils, transformers, and wire harnesses; contacts, relay contacts, and switches; fuses, resistors, heaters, wires, and welds; conductive rubber and paint; and compact magnetic components such as EMC filters and ferrite beads. Application examples include measuring a 3-phase motor winding, testing a connector or wiring harness, testing a relay, and testing battery terminal welds. The instruments are also cited for testing inverter motor windings, current sensing resistors, and current detectors.

ValueTronics supplies the RM3545 and RM3544 from its own 20,000-square-foot secure warehouse at 1675 Cambridge Drive in Elgin, Illinois, where we stock and hold our own inventory.

Compare Other Models in This Series

The RM3545 and RM3544 form a two-model resistance-meter line that lets you choose based on your application. The RM3545 is presented as a super-high-accuracy, multi-channel meter for advanced development and production applications, delivering 0.006% basic accuracy and 0.01 μΩ resolution. The RM3544 is presented as a high-accuracy bench-top meter for both manual operation and integration with automatic lines, delivering 0.02% basic accuracy and 1 μΩ resolution.

Each base model is also offered in interface and channel variants: the RM3545 in base, -01 (adding GP-IB), and -02 (supporting the Multiplexer Unit), and the RM3544 in base and -01 (adding EXT I/O, RS-232C, and USB). Selecting a model means matching the required resistance range, accuracy, and interface or channel capability to the measurement task.

Each new model linked below is its own product page with condition-matched pricing. Compare the model rows to confirm the resistance range, accuracy, and interface or multiplexer capability that fit your application before selecting a specific new unit.

The RM3545 is the only model in this pairing to offer low-power (LP) resistance measurement, offset voltage compensation (OVC), D/A output, and temperature conversion for temperature-rise testing, and in the RM3545-02 it adds multiplexer scanning of up to 20 channels with 4-terminal measurement.

The principal differences between the two models are range, resolution, accuracy, and drive current. The RM3545 measures up to 1200 MΩ at 0.01 μΩ resolution, 0.006% basic accuracy, and up to 1 A measurement current, while the RM3544 measures up to 3.5 MΩ at 1 μΩ resolution, 0.02% basic accuracy, and up to 300 mA. The RM3545 also offers up to a 6.5-digit display versus up to 4.5 digits on the RM3544.

Functionally, the RM3545 adds low-power resistance measurement, offset voltage compensation, D/A output, temperature conversion, and optional 20-channel multiplexer scanning — capabilities the RM3544 does not provide. Interface availability also differs by variant, with GP-IB exclusive to the RM3545-01 and the RM3544 base model carrying no communication interfaces. The comparison table below details these per-model differences.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Accessories Supplied

• Power cord ×1
• CLIP TYPE LEAD L2101 ×1
• Temperature Sensor Z2001 ×1
• Male EXT. I/O connector ×1
• Instruction manual ×1
• Application disc ×1
• USB cable (A-to-B type) ×1
• Spare fuse ×1

Replaces: per the manufacturer, this model replaces 3540, 3541.

Product Core & Specifications

Important: Proper operation of the RM3545 and RM3544 is not guaranteed when using test leads that lack guard terminals — use the guard-terminal test leads specified for these models.

Important: The RM3544 (base model) does not include EXT I/O or communication interfaces (RS-232C or USB). Select the RM3544-01 for these functions.

Important: Multiplexer Units (Z3003) cannot be installed in the RM3545 or RM3545-01; only the RM3545-02 supports the multiplexer. The RM3545-01 has a GP-IB connector.

Important: The Multiplexer Unit Z3003 cannot be used in combination with a withstand voltage tester; when used with a withstand voltage tester, the Z3003's internal relay will cause an insulation breakdown, resulting in electric shock or equipment damage.

Important: Temperature correction requires the Temperature Sensor Z2001 (or a thermometer capable of analog voltage output, such as an infrared thermometer). The Z2001 is a bundled accessory on the RM3545/RM3545-01/RM3545-02 but is an option for the RM3544/RM3544-01.

Important: RM3545 accuracy is specified with a warmup time of 60 minutes or greater; if warmup is less than 60 minutes, double the figures in the accuracy table to obtain the measurement accuracy.

Recommended pairing: install the Multiplexer Unit Z3003 in the RM3545-02 to enable scanning measurement of up to 20 locations with 4-terminal measurement.

ValueTronics supplies both new and used test and measurement equipment. New units ship factory-sealed, exactly as received from the manufacturer; every used unit is inspected and functionally verified in-house at our 20,000 sq ft secure facility in Elgin, Illinois before it ships. Our Test Architects can help you select the condition, calibration, and configuration that fit your application.

Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.