Created on 2010-09-21 07:51:00
Q: I want to make a frequency response measurement. Should I use Analyzer.Level A or Analyzer.Amplitude A in the Data 1 section of the Sweep panel? What fundamentally is the difference between the Level and Amplitude meters?
AP2700 Analyzer panel showing the level and amplitude meters.
A: The Level meters have superior response flatness and amplitude accuracy, but are fully specified only down to 5 mV. However, they are useful for most applications at amplitudes far below that. They are always RMS responding, and lie before the bandwidth and filter stages of the input.
The Amplitude meter has five different detector responses (RMS, Average, Peak, Quasi-Peak (Q-Peak), and Sine Scaled Peak (S-Peak)), and can be filtered and bandwidth limited. Bandwidth limiting is very important when out-of-band components of the signal (switching noise, converter noise, high-frequency bias, etc) are significant and may contribute errors to the response measurement.