Teledyne HDO9000, Руководство оператора

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HDO9000 High Definition Oscilloscopes Operator's Manual
Probe Attenuation and Deskew
Probe Attenuation and Deskew values for third-party probes may be entered manually on the C x
dialog. The instrument will detect it is a third-party probe and display these fields.
When a Teledyne LeCroy probe is connected to a channel input:
l
Passive probe Attenuation is automatically set, and this field is disabled on the C x dialog.
l
For active voltage and current probes, a tab is added to the right of the C x tab. The Attenuation
field becomes a button to access the Probe dialog . Enter Attenuation on the Probe dialog.
Rescale Settings
The rescale function allows you to apply a multiplication factor, additive constant, and differential
vertical unit to the waveform vertical samples.
Vertical Units may be changed from Volts (V) to Amperes (A). This is useful when using a third-party
current probe (which is not auto-detected) or when probing across a current sensor/resistor.
Enter the desired values in Units/V and Add . These two selections provide the same capability as the
Rescale math function (y=mx+b) but in a more intuitive, user-friendly format.
Pre-Processing Settings
Average performs continuous averaging or the repeated addition, with unequal weight, of successive
source waveforms. It is particularly useful for reducing noise on signals drifting very slowly in time or
amplitude. The most recently acquired waveform has more weight than all the previously acquired
ones: the continuous average is dominated by the statistical fluctuations of the most recently
acquired waveform. The weight of old waveforms in the continuous average gradually tends to zero
(following an exponential rule) at a rate that decreases as the weight increases.
Interpolate applies (Sinx)/x interpolation to the waveform. The default selection of None applies
Linear interpolation, which inserts a straight line between sample points and is best used to
reconstruct straight-edged signals such as square waves. (Sinx)/x interpolation, on the other hand, is
suitable for reconstructing curved or irregular wave shapes, especially when the sample rate is 3 to 5
times the system bandwidth. Select an upsample factor of 2 or 5 points between each sample point.
Interpolation is disabled when in HD Mode .
Deskew adjusts the horizontal time offset by the amount entered in order to compensate for
propagation delays caused by different probes or cable lengths. The valid range is dependent on the
current timebase setting. The Deskew pre-processing setting and the Deskew math function perform
the same action.
Noise Filter applies Enhanced Resolution (ERes) filtering to increase vertical resolution, allowing you
to distinguish closely spaced voltage levels. The tradeoff is reduced bandwidth. The functioning of
the instrument's ERes is similar to smoothing the signal with a simple, moving-average filter. It is
best used on single-shot acquisitions, acqusitions where the data record is slowly repetitive (and you
cannot use averaging), or to reduce noise when your signal is noticeably noisy but you do not need to
perform noise measurements. It also may be used when performing high-precision voltage
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