16
Aug
Oscilloscopes are electronic instruments that display signal voltages on a graph. Various signals can be converted to voltages and displayed on the X and Y axis of the display. The vertical Y axis represents voltage, while the horizontal X axis represents time and the visual representation of the signal can be viewed as a repeating image.
There are various types of oscilloscopes with a number of different purposes in telecommunications, medicine, engineering, and so on. The two main types however, are the analogue and the digital oscilloscope. Although some engineers love the look and feel of analogue oscilloscope, the fact is, this is a rather outdated technology with limited performance and I wouldn’t suggest on buying one, unless, of course, you are a collector. If you are going to buy oscilloscope, you should definitely get a digital one which is far more superior to analogue oscilloscopes. Digital oscilloscopes are small and portable, have the highest bandwidths, colour displays, on-screen measurements, simple interface, they provide storage, printing and PC connectivity.
When you are looking to to buy oscilloscope there are a number of things you should have in mind in order to make the right choice.
First you need to consider the bandwidth. A common practice is to purchase an oscilloscope that has a bandwidth fife times higher that the maximum frequency you are measuring. Although high-bandwidth oscilloscopes can be quite expensive, they ensure accurate representation of the waveform.
The sampling rate is another important factor. Oscilloscopes usually have two sampling rates: real-time sampling (RTS) and equivalent-time sampling. They are specified in megasamples per second (MS/s) or gigasamples per second (GS/s). When you are choosing oscilloscopes, find out which type of sampling the spec applies to.
Choose an oscilloscope with a good memory depth. The captured points are stored in the memory and the amount of memory of the oscilloscope determines how long it will store the signal before having to delete it. Insufficient memory can limit the sampling rate of the oscilloscope.
Traditional oscilloscopes with two or four channels may not be enough to view the signals of interest in today’s digital world. Most of the modern models have up to four analog and sixteen digital channels for logic timing.
Most of the digital oscilloscopes have 8-bit resolution because they are designed for digital signals. However, for audio, automotive, or environmental signals you will need 12-bit or even 16 -bit resolution and the higher the resolution the bigger accuracy you get.
And finally, consider how you are going to use the oscilloscope and choose between a handheld model for or a PC base module that plugs into a computer or a lap top.
It definitely takes a little background knowledge and a fair amount of research to find the right oscilloscope, but once you know what you are looking for, it shouldn’t be a difficult task.
