Spescom MeasureGraph, local distributor for Fluke, has available the new ScopeMeter 190C series that adds a large, high resolution colour screen and extended functionality. These high-performance handheld oscilloscopes, the 196C and 199C, include a 'digital persistence' feature and also have a much faster display update rate.

A colour display makes identification of individual waveforms easier, particularly when displayed with large amplitudes on screen. Fluke says that this also makes it possible to visually distinguish individual traces if waveforms are displayed on top of, or very close to each other. Larger waveforms can be displayed without confusion between individual traces. Colour is also used for on-screen labels and warnings, making it easier to distinguish them and to link information to specific waveforms. The display is brighter, and high contrast allows for clear reading under varying light conditions. And, according to the manufacturer, four hours battery operating time is still assured.

Waveforms as on analog scope

Fluke says that the digital signal processing core has been newly designed. Its 'digital persistence' mode gives the instrument an analog oscilloscope like waveform decay, which is especially useful when working with complex or modulated, dynamic signals. Where a scope's display normally represents amplitude as a function of time, digital persistence shows the amplitude distribution over time using multiple intensity levels and a user-selectable decay time. This results in a waveforms display similar to that of an analog oscilloscope. With the faster display update rate, signal changes are seen immediately, giving an actual representation of the signal's dynamic behaviour. This is also particularly useful when making fine adjustments of a system.

Screen resolution is now higher, (320 x 240 pixels), giving a 20% larger screen and deeper memory (1200 instead of 1000 samples in scope mode, or 27 500 samples in ScopeRecord mode). This enhances the waveform detail to be displayed for a longer period of time. An engineer can now fix more because he can see more, says Fluke.

More functions

The ScopeMeter 190C series has other new features. These include a 'stop on trigger' to store pre-trigger waveform data in the scope.

Record mode and a 'waveform reference' feature allowing an acquired trace to be stored as 'reference' to visually compare new waveforms against. To allow users to measure the effective output voltage of variable speed motor drives and frequency inverters, a VPWM measurement is also built in.

When Fluke launched the original ScopeMeter 190 Series, it introduced field engineers to hand-held instruments with the speed, performance and analysis power usually found only on high-end bench oscilloscopes. The Fluke 199 (the top-of-the-range model) has a 200 MHz bandwidth and 2,5 GSa/s realtime sampling rate per input; other models are 100 MHz and 60 MHz. They all are two-channel oscilloscopes with independently floating isolated inputs up to 1000 V. The 190 series provides unique features like connect-and-view triggering and automatic capture and replay of the last 100 screens. The latest additions, the 199C and 196C bring the benefits of a full-colour display to handheld scopes.

All Fluke's 190 Series ScopeMeters are 1000 V CAT II and 600 V CAT III safety certified (EN-61010-1). As handheld instruments, long battery life is essential, and so the new 190C Series gives the same four hours operating time per recharge of its NiMH battery packs. The latest FlukeView software release also supports the use of colour for waveforms, and extensive user documentation is supplied on CD-ROM in nine languages.