Electronic Design
Handheld Scopes Bring Near-Bench Precision

Handheld Scopes Bring Near-Bench Precision

It’s pretty difficult for portable test instruments to deliver all of the measurement power of benchtop units. The portable versions obviously can go places that the benchtop units cannot, but generally speaking, they’re not quite up to the performance of their bench-bound big brothers.

But there’s a tightrope walk involved in the design of portables. Tektronix has walked that tightrope numerous times over the years and has done so again with the launch of its THS3000 series of handheld scopes (see the figure). This time, the company aimed to deliver a portable scope with enough performance, flexibility, and versatility to be useful both on the bench and in the field.

With the THS3000 line, Tektronix wants to address two distinct groups of users: those who are using scopes in a traditional fashion to validate their designs, and those who are taking them out into the field for measurements in more challenging environments.

Both groups need to be able to measure floating and isolated signals. In the lab, there’s the need to debug digital control and analog circuitry and to capture single-shot and intermittent events. Field users need to be able to correlate measurements taken in the lab with those taken elsewhere.

With bandwidths of either 100 MHz or 200 MHz and a 5-Gsample/s maximum sampling rate, the four-channel THS3000 scopes have enough horsepower to snag those transient glitches. Moreover, the channels are well and truly isolated from each other as well as from ground. Inputs are rated to a maximum 300 VRMS, CAT III between the probe inputs and BNC shell. Interestingly, Tek has designed new probes for these scopes with plastic shells.

Portable handheld scopes with four channels aren’t all that common. Having four channels is really useful for work with things like inverters or motor drives, where you’re scoping a three-phase input. Two channels just won’t cut it.

Other performance attributes include a 10k record length per channel, which is tripled in slow-speed (or roll) mode. There are also advanced triggering capabilities, such as bi-slope triggering, which lets you trigger on either rising or falling edges.

On the bench, the scopes provide a comprehensive set of analysis tools. There are 21 different user-selectable automatic measurements, as well as on-screen cursors that can be configured in a variety of ways. There are user-definable waveform math functions, a fast Fourier transform (FFT) spectral display, and waveform persistence, a feature that’s not often found in lower-end scopes.

These scopes are well thought out in terms of ease of use. Autosetting and autoranging functions are standard, as are internal measurement data logging and automatic waveform recording. A user-replaceable battery is a nice touch.

The series includes two models: one with 100-MHz bandwidth and a maximum sampling rate of 2.5 Gbits/s, and one with 200-MHz bandwidth and a 5-Gbit/s sampling rate. Each scope is also offered as a travel kit with a hard case for protection and storage of accessories. The case will hold a full-sized laptop. Prices start at $3950 (100-MHz scope; no travel kit) and top out at $4900 (200-MHz model with travel kit).


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