Expand with Multiplexer to Streamline Testing

Nagano, Japan

Hioki E.E. Corporation announces the launch of the Resistance Meter RM3545, a high-precision wide-range resistance tester for both R&D and production lines.

Electric vehicles built with high efficiency motors and inverters and solar power systems integrated with power conditioners are expected to see even greater utilization in the future. These devices make extensive use of coils, inductors, and other electronic components that exhibit very low resistance values, and to ensure performance, they need to be tested at high levels of precision during the development and production process. The Hioki Resistance Meter RM3545 meets these needs by delivering a broad measurement range and superior measurement accuracy. It also offers a high maximum resolution, allowing more minuscule changes to be captured.

In addition, the new Resistance Meter RM3545 features a multiplexer function available through an optional expansion board. When installed, the multiplexer function enables automatic 4-terminal measurement of resistance to be performed sequentially at up to 20 locations, remarkably improving measurement efficiency.

Development Background
Currently, progress in energy-saving initiatives is being matched by the accelerated use of renewable energy. At the same time, increased advancements in technologies such as electric automobiles and solar power systems are forecasted, and the market for electronic components such as coils and inductors, indispensable building blocks of these technologies, is expected to expand.

This leads to the rising need in the ability to measure low resistance values at higher levels of precision during the development and production of these electronic components, and to aptly meet such need, Hioki has developed the Resistance Meter RM3545. On the opposite spectrum, electronic components make extensive use of materials with high resistance values, for example conductive sheets and conductive rubber. The Hioki RM3545 was also developed to accommodate such materials.


1. Hioki Resistance Meter Lineup: Broad measurement range and high-precision measurement capabilities
(1) Measurement range and measurement accuracy
Last year, HIOKI launched the RM3544, which is designed for use on production lines, and the RM3548, which is designed for use in maintenance applications. Compared to these two instruments and to a similar previous model (Hioki 3541), the RM3545, which is designed primarily for use in research and development, offers a broader measurement range, as well as improved basic accuracy.
(2) Maximum resolution
Resolution refers to the smallest unit that a measuring instrument can detect. The greater this resolution (the smaller this unit), the more minuscule the changes that can be detected. The RM3545’s maximum resolution is 0.01 Ω, an order of magnitude better than Hioki’s previous Model 3541.

2. Multiplexer function (automatic, sequential 4-terminal measurement of up to 20 electronic component resistance locations)
The RM3545’s multiplexer function can be used by installing an optional Multiplexer Unit Z3003 into the instrument. This function automatically performs 4-terminal measurement of resistance at up to 10 locations per Multiplexer Unit, dramatically improving measurement efficiency. Since two Multiplexer Units can be installed in one Resistance Meter at the same time, up to 20 locations can be automatically measured in this manner.

As an example, a 3-phase motor contains numerous coils, resolvers, and other electronic components, making it extremely time-consuming for a researcher to measure each manually. The benefits of the RM3545’s multiplexer function, which automates this process, is particularly clear in such applications.

3. Extensive contact check functionality to prevent erroneous measurement
When measuring electronic components, there is a risk of erroneous measurement for various reasons, for example due to the failure of the measurement terminals to make proper contact with the object under measurement. To prevent such problems, Hioki equipped the RM3545 with extensive contact check functionality that identifies an error if the measurement terminals have not been placed in proper contact with the object under measurement. In this way, the instrument makes more reliable measurement possible.

4. Easy-to-understand audible notification of PASS/FAIL results
Many resistance measurement applications involve conducting tests to determine whether the object under measurement yields a value that falls within a predetermined range. In such applications, the Resistance Meter RM3545 notifies the technician of the test results by emitting a loud beep. Additionally, an optional LED Comparator Attachment allows users to ascertain results without needing to look up at the instrument’s display, thereby boosting work efficiency.

* Evaluation and testing of coils, inductors, and other electronic components

Established in 1935, HIOKI E.E. CORPORATION (TSE: 6866) has grown to become a world leader in providing consistent delivery of test and measuring instruments through advanced design, manufacturing, and sales and services. By offering over 200 main products characterized by safety and quality while meeting an expansive range of applications, we aim to contribute to the efficiency and value of our customers’ work in research and development, production and electrical maintenance. HIOKI products and services are available around the world through our extensive network of subsidiaries and distributors. Information about HIOKI is available at https://hiokiusa.com.