The HIOKI RM3545 and RM3544 are high-accuracy, bench-top resistance meters that measure resistance using a 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 an easy-to-use meter suited to both manual operation and integration with automatic lines. Both deliver guaranteed accuracy immediately after startup, with no warm-up or zero-adjustment required.

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 RM3545 additionally addresses multi-contact resistance measurement of motor and transformer windings as well as small-signal contacts, including compact fuses and airbag inflators.

ValueTronics stocks and holds its own test-and-measurement inventory in a 20,000-square-foot secure warehouse at 1675 Cambridge Drive in Elgin, Illinois, and has specialized in new and used instrumentation since 1992.

Compare Other Models in This Series

The RM3545 and RM3544 form a two-model resistance-meter range, and the right choice depends on the application. The RM3545 is the super-high-accuracy, multi-channel model intended for advanced development and production applications, while the RM3544 is an easy-to-use, high-accuracy meter built for both manual operation on production lines and integration into automatic test lines.

Both share the same 4-terminal DC measurement method with a guard terminal, along with temperature correction, comparator judgments with user-selectable tones, scaling, and auto hold, and both run on a 100–240 VAC supply. The differences lie in measurement range, resolution, accuracy, and the advanced functions and interfaces each model offers, detailed in the comparison table below.

Each new model linked below is its own dedicated product page with condition-matched pricing. Select the model and configuration that fits your application to view the specifications and availability for that unit.

The RM3545 is distinguished within the range by functions the RM3544 does not provide, including low-power (LP) resistance measurement, offset voltage compensation (OVC), a temperature-conversion function for temperature-rise testing, D/A output of the measured value, and — in the RM3545-02 configuration — multiplexer-based scanning of up to 20 locations with 4-terminal measurement.

In measurement performance, the RM3545 provides a 6.5-digit (1,200,000-count) display, 0.01 μΩ maximum resolution, 0.006% basic accuracy, a measurement range to 1200 MΩ, and up to 1 A of measurement current. The RM3544 provides up to a 4.5-digit display, 1 μΩ maximum resolution, 0.02% basic accuracy, a range to 3.5 MΩ, and up to 300 mA of measurement current.

The models also differ by configuration. The base RM3544 has no communication interfaces, while the RM3544-01 adds EXT I/O, RS-232C, and USB. Among the RM3545 variants, the base RM3545 and RM3545-01 cannot accept multiplexer units; the RM3545-01 adds a GP-IB connector, and only the RM3545-02 supports the Z3003 Multiplexer Unit for 4-terminal scanning. Refer to the comparison table for a model-by-model breakdown.

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

Product Core & Specifications

Important: Proper operation of the RM3545 and RM3544 is not guaranteed when using test leads (probes) that lack guard terminals; use the specified guard-terminal test leads.

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

Important: Temperature correction requires the Temperature Sensor Z2001 or a thermometer capable of generating analog voltage output (e.g. an infrared thermometer). The Z2001 is a bundled accessory with the RM3545/RM3545-01/RM3545-02 but is an option (not bundled) for the RM3544/RM3544-01.

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

Important: RM3545 only: accuracy requires a warm-up time of 60 minutes or greater; if less than 60 minutes, double the figures in the accuracy table to obtain the measurement accuracy.

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

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.