Tektronix TDS1000B Series Operator's Manual page 43

1
Introduction to Oscilloscopes and Probes
Capacitive Loading
An increase in signal frequency or transition speed
decreases the reactive impedance of a capacitive element.
Consequently, capacitive loading increases the rise and fall
times on fast transition waveforms and decreases the
amplitude of high frequency details in waveforms.
When the output of a pulse generator is tested, the probe
input capacitance and resistance will interact with the pulse
generator impedance. Probe resistance is usually ignored
because it is generally much greater than the generator
resistance. However, probe capacitance adds to the total
load capacitance and increases the measured rise time.
TDS1000B and TDS2000B Series Oscilloscopes – Operator Training Kit 1-29