User manual

ManualsBrandsPICO ManualsLaboratory Test EquipmentPC scope module Scope 6402D 250 MHz 8-channel 5 null 512 null 8 Bit Digital storage (DSO), Function generator,

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7.4.1

Spectrum Options dialog

This dialog appears when you click the Spectrum Options button in the Capture

Setup toolbar. It is available only when a spectrum view is open. It contains controls

that determine how PicoScope converts the source waveform in the current scope view

to a spectrum view.

Spectrum

Bins

The number of frequency bins into which the spectrum is

divided. This control sets the maximum number of frequency

bins, which the software may or may not be able to provide

depending on other settings. The main constraint is that the

number of bins cannot greatly exceed half the number of

samples in the source waveform.

If the source waveform contains fewer samples than required

(that is, fewer than twice the number of frequency bins), then

PicoScope zero-pads the waveform up to the next power of two.

For example, if the scope view contains 10,000 samples, and

you set Spectrum Bins to 16384, then PicoScope zero-pads the

waveform to 16,384 samples, which is the nearest power of two

above 10,000. It then uses these 16,384 samples to provide

8,192 frequency bins, not the 16,384 requested.

If the source waveform contains more samples than required,

then PicoScope uses as many samples as necessary, starting

from the beginning of the waveform buffer. For example, if the

source waveform contains 100,000 samples and you request

16,384 frequency bins, PicoScope needs only 2 x 16,384 =

32,768 samples, so it uses the first 32,768 samples from the

waveform buffer and ignores the rest. The amount of data

actually used is displayed as the Time Gate setting in the

Properties sheet.

Window

Function

Allows you to choose one of the standard window functions to

reduce the effect of operating on a time-limited waveform. See

Window functions.

Display

Mode

You can choose Magnitude, Average or Peak Hold.

Magnitude: the spectrum view shows the frequency spectrum

of the last waveform captured, whether live or stored in the

waveform buffer.