HIOKI RM3544 4.5-Digit Resistance Meter

Key Features At A Glance

• 4-terminal DC resistance measurement with guard terminal to reduce external noise
• Resistance range spans µΩ-level resolution up to 1200 MΩ across the series (model-dependent)
• Basic accuracy from 0.02% to 0.006% across the series, display from 4.5 to 6.5 digits
• Temperature correction and scaling convert readings to a reference temperature or physical units
• Comparator (ABS/REF%) with user-selectable judgment tones and auto hold for pass/fail line testing
• Guaranteed accuracy from startup — no warm-up or zero-adjustment required
• EXT I/O handler, RS-232C, USB, and GP-IB interfaces available across the series for ATE integration
• Optional Z3003 Multiplexer Unit scans up to 20 locations with 4-terminal measurement (RM3545-02)

The HIOKI RM3545 and RM3544 are bench-top DC resistance meters built for high-accuracy four-terminal measurement on production lines and in development labs. The RM3545 is positioned as a super-high-accuracy, multi-channel meter for advanced development and production applications, while the RM3544 is an easy-to-use meter that suits both manual operation and integration with automatic lines. Both perform four-terminal (Kelvin) direct-current resistance measurement using a constant-current method with a guard terminal that minimizes the effect of external noise.

Across the series the meters are applied to a wide span of components: motors, solenoids, choke coils, transformers, and wire harnesses; contacts, relay contacts, and switches; fuses, resistors, heaters, wires, and welds; and high-resistance materials such as conductive rubber and paint. The RM3545 additionally addresses compact fuses, airbag inflators, and compact magnetic components such as EMC filters and ferrite beads, along with multi-contact resistance measurement of motor and transformer windings and small-signal contacts. Illustrated application setups include measuring a three-phase motor winding, testing a connector or wiring harness, testing a relay, and testing battery terminal welds.

ValueTronics stocks and holds its own inventory in a 20,000-square-foot secure warehouse at 1675 Cambridge Drive in Elgin, Illinois, so the resistance meters listed here are managed directly by our team.

Compare Other Models in This Series

The RM3545/RM3544 series comprises two bench-top resistance-meter lines that HIOKI positions by application. The RM3545 is described as a super-high-accuracy, multi-channel meter for advanced development and production applications, while the RM3544 is an easy-to-use meter that suits both manual operation and integration with automatic lines. HIOKI frames the choice between the two models around the intended measurement application.

Within each line, configuration variants extend connectivity and channel count. The RM3545 is available as the base model, the RM3545-01 with a GP-IB connector, and the RM3545-02 that supports the optional Multiplexer Unit Z3003. The RM3544 is offered as a base model and as the RM3544-01, which adds EXT I/O and RS-232C/USB communication interfaces.

Each model and configuration linked below is its own dedicated product page with new pricing matched to its condition. Select the specific model and variant that fits your channel-count, accuracy, and interface requirements to see its current new availability.

The RM3545 is the only line in the series to offer low-power (LP) resistance measurement, offset voltage compensation (OVC), temperature conversion (Δt) for temperature-rise testing, and D/A output, and — in the RM3545-02 — multiplexer-based scanning of up to 20 four-terminal locations. It reaches 0.006% basic accuracy and 0.01 µΩ resolution across a range extending to 1200 MΩ.

The two lines differ first in measurement range and precision: the RM3545 spans 0.00 µΩ to 1200 MΩ with 0.006% basic accuracy, 0.01 µΩ resolution, and up to 1 A measurement current, while the RM3544 spans 0.000 mΩ to 3.5 MΩ with 0.02% basic accuracy, 1 µΩ resolution, and up to 300 mA. The RM3545 provides a 6.5-digit display versus the RM3544's 4.5 digits.

They also differ in function set and connectivity. Low-power measurement, offset voltage compensation, temperature conversion (Δt), D/A output, and multiplexer support are provided on the RM3545 and are not available on the RM3544. EXT I/O and RS-232C/USB communications are standard on the RM3544-01 (not the base RM3544), are available on the RM3545 line, and GP-IB is specific to the RM3545-01. The comparison table that follows details each model's range, accuracy, and interface options.

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
• instruction manual ×1
• extra 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.

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: Multiplexer Units (Z3003) cannot be installed in the RM3545 or RM3545-01; only the RM3545-02 supports the Z3003.

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

Important: 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: RM3545 only: a warmup time of 60 min. or greater is required for full guaranteed accuracy; if less than 60 min., double the figures in the accuracy table to obtain the measurement accuracy.

Usage tip: pair the RM3545-02 with the optional HIOKI Multiplexer Unit Z3003 to scan up to 20 locations with 4-terminal measurement.

About this New unit

This is a brand-new, factory-sealed unit, supplied exactly as it arrives from the manufacturer and backed by the full manufacturer warranty. For the exact configuration, available options, included accessories, or current lead time for your application, our Test Architects can confirm the details before you order.

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.