Agilent Technologies InfiniiVision 3000 User Manual page 83

Scale and offset considerations
N O T E
If you do not manually change the FFT scale or offset settings, when you turn the horizontal
scale knob, the span and center frequency settings will automatically change to allow
optimum viewing of the full spectrum.
If you do manually set scale or offset, turning the horizontal scale knob will not change the
span or center frequency settings, allowing you see better detail around a specific
frequency.
Pressing the FFT Auto Setup softkey will automatically rescale the waveform and span and
center will again automatically track the horizontal scale setting.
3 To make cursor measurements, press the [Cursors] key and set the
4 To make other measurements, press the [Meas] key and set the Source
The following FFT spectrum was obtained by connecting a 4 V, 75 kHz
square wave to channel 1. Set the horizontal scale to 50 µs/div, vertical
sensitivity to 1 V/div, Units/div to 20 dBV, Offset to - 60.0 dBV, Center
frequency to 250 kHz, frequency Span to 500 kHz, and window to
Hanning.
Agilent InfiniiVision 3000 X-Series Oscilloscopes User's Guide
Source softkey to Math: f(t).
Use the X1 and X2 cursors to measure frequency values and difference
between two frequency values ( X). Use the Y1 and Y2 cursors to
measure amplitude in dB and difference in amplitude ( Y).
softkey to Math: f(t).
You can make peak- to- peak, maximum, minimum, and average dB
measurements on the FFT waveform. You can also find the frequency
value at the first occurrence of the waveform maximum by using the X
at Max Y measurement.
4
Math Waveforms
83