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Instrument troubleshoots drives and field buses

10 April, 2007

Fluke has launched a handheld instrument which incorporates functions for troubleshooting motor drives, as well as testing the signal quality on field buses such as Profibus and Modbus. The Fluke 125 Industrial ScopeMeter combines a 40MHz dual-input digital oscilloscope, two 5,000-count true-rms multimeters, and a dual-input paperless recorder for tracking intermittent faults.

Fluke ScopeMeter

The instrument (shown above) can analyse harmonics up to the 33rd, and power measurements for single- and three-phase systems, over a wide frequency range. It can also provide VPWM measurements to indicate the true output voltage of motor drives, and perform high-resolution resistance measurements for fault-finding in motor windings.

A triggering function that recognises signal patterns and sets up the correct triggering automatically, makes it easier to measure drive and control signals. It is said to result in stable, repeatable displays of almost any signal and to overcome problems of manual trigger setting which can result in unstable, incorrect results.

The ScopeMeter’s "paperless recorder" captures minimum and maximum peak values and averages, over periods of up to 16 days. The two inputs can plot any combination of voltage, current, temperature, frequency and phase, with time and date stamps, to help pinpoint intermittent faults. The instrument includes a 400A current clamp.