Latest Test and Measurement News

Resistance Meter for Component and Equipment Testing

23 January 2013 - HIOKI E.E. Corporation launched the resistance meter RM3544 and RM3548. Manufacturers of coils and inductors must measure DC resistance as part of the production process, and HIOKI developed the RM3544 Series and RM3548 to meet this need in different applications.

The RM3544 Series is designed primarily to be embedded in automatic testing systems on production lines as well as for use on manual lines where technicians make measurements directly. The RM3544 Series uses a measurement current of up to 300 mA and features a measurement unit with guarded terminals, decreasing the effects of noise on measured values. Additionally, the instrument is capable of high-accuracy measurement with a measurement accuracy of up to 0.02%.

The instruments boast a footprint that is 25% smaller than the instrument it replaces, the popular HIOKI 3540. Their compact design frees up space when integrated in a production line, increasing the degree of freedom with which equipment can be laid out.

Resistors are subject to PASS/FAIL tests before shipment. Used in this type of application, the RM3544 Series can indicate the test results with a loud sound and bright light. The optional LED Comparator Attachment further boosts work efficiency by allowing operators to assess results simply by looking down at their hands rather than at the instrument’s screen.

 Resistance Meter RM3548

The RM3548 features a portable design that allows it to be used not only in the production, maintenance, and inspection of large coils, motors, and transformers, but also in applications such as the testing of electric vehicles, hybrid vehicles, and aircraft. Despite a portable, battery-powered design, the instrument is capable of highly reliable measurement thanks to a measurement current of 1 A, a maximum measurement accuracy of 0.02%, and a measurement range of 0.000 mΩ to 3.5000 MΩ.

Components known as windings, which are used internally in equipment such as motors and transformers, must be tested for temperature changes to verify that they do not throw off an abnormal amount of heat when a large voltage is applied. However, because they are located inside motors and other equipment, the temperature of windings cannot be measured directly. Instead, it is typical to use a temperature testing technique in which a resistance value is measured and converted to a temperature.

Since the RM3548 provides an interval measurement function that can take readings continuously at an interval as short as 0.2 seconds, the instrument is ideal for use in temperature testing.

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