The Best In-Class Viewing Oscilloscope Under $2000!

If you think viewing signals is the 1st order value of an Oscilloscope, think Rigol!

The vast majority of oscilloscope users are primarily concerned with how a scope "displays" signals. RIGOL Technologies, who is new to the North American market and is capturing unprecedented market share, has addressed this need by focusing on sensible engineering and the foremost materials to deliver the best viewing oscilloscopes in their respective class of products. From Rigol's perspective, waveform viewing is critical and a superior oscilloscope must address three aspects to excel at troubleshooting and basic waveform observation: Acquisition, Event Isolation and the Viewing Display.

1.) Acquisition

An oscilloscope must have enough performance, measured by bandwidth and sampling rate, to accurately capture the signal. RIGOL has intelligently designed a variety of front-end signal conditioning circuits that are optimized for varying bandwidths up to 300 MHz, the highest bandwidth available for oscilloscopes under $2000.

The most dubious specification to be considered when deciding on the right oscilloscope for your application is an oscilloscope's sampling rate. Many manufacturers will try and sell customers on the premise that their scope has the highest sampling rate available. However, the notion that "the higher the sampling rate, the better the oscilloscope" is a myth when considering the application the oscilloscope is designed for according to its bandwidth limitations.

So what are the facts?

If you are acquiring a signal only once (i.e. single shot), you need at least twice the sampling rate as that of the maximum frequency in your signal. This is based on the "Nyquist" theorem, which is a generally accepted principle engineers follow when performing analog to digital conversions. The Nyquist theorem indicates a factor of twice the bandwidth in sampling rate is sufficient in acquiring and converting a signal.

However, some oscilloscopes manufacturers suggest that you need 10 times the sample rate of the bandwidth. While this may be nice, it is certainly not necessary to accurately acquire and display a signal under test. Too much sampling rate may only drive up the cost of your oscilloscope.

Rigol's product are engineered to a sampling rate of 3 to 5 times the bandwidth of the oscilloscope and use a Sinx/x filter that does a great job of recreating the signal. The end result from Rigol is an oscilloscope that is optimized for performance, allowing customers to avoid the unnecessary expense for extra digitizing that brings little incremental advantage.

2.) Event Isolation

The real power of a digital oscilloscope is in its ability to isolate and store events. This functionality offers incredible value during troubleshooting and the cornerstone of isolating an event is triggering. RIGOL oscilloscopes have been designed from the inception to provide powerful and easy triggering options that make isolating events a breeze.

Rigol oscilloscopes offer several triggering modes:

1. Edge Triggering - Triggering on a rising or falling edge at a certain voltage.

2. Pulse Triggering - Triggering to a positive or negative pulse that is present for a user-defined time, like Glitch triggering.

3. Slope Triggering - Triggering when the slope of a signal transition is faster or slower than the user defined setting. Slope triggering is very useful in looking at tri-state conditions.

4. Pattern Triggering - When using a RIGOL Mixed Signal Oscilloscope (MSO) you can trigger on any pattern of 1, 0s from the 16 inputs on the MSO.

5. Alternate Triggering - Triggering across two channels to provide a true dual time base where each channel can sample at different rates based on their set-up.

Rigol's oscilloscope triggering capabilities are the most powerful of any oscilloscope under $2000.

3.) Viewing Display

When it comes to oscilloscopes, the display is the last critical component of a superb viewing tool. Rigol incorporates a TFT color display in all their products, which provide a superior color, brightness and viewing angle than that of the standard and less expensive LCD display.

Critical to an oscilloscope's viewing display performance is the Update Rate. Most customers would like a real time and responsive feel when using a digital oscilloscope to acquire a signal. RIGOL has optimized their update rate to achieve 1000 waveforms per second and their newest oscilloscopes realizing 2000 waveforms per second with the addition of an FPGA.

In Conclusion:

The bottom line is that RIGOL takes viewing signals seriously and has invested considerably and intelligently in engineering a product that is the best viewing scope in its class. If you are looking for a superb viewing oscilloscope without spending excess dollars on unnecessary and unutilized performance metrics, think Rigol!

Robert Preville is the President and CEO of Global Test Supply, LLC, a distributor of test and measurement equipment, and welcomes questions from those looking for an Oscilloscope.