Voltage measurements are easy to make; even if we did not have our extremely accurate CompuLAB USB interface which is responsible for all of our voltage measurements, a good multimeter with an USB interface would do the job. However ripple can only be measured by using an oscilloscope meeting certain specifications. We decided to acquire an USB Instruments Stingray oscilloscope simply because it is the most popular device used for that purpose today and, like every other measurement instrument we are using, its results are being transferred directly to our PC.