OperatingBasics
14 P5205 Instruction Manual
With extension leads Without extension leads
50ns/div 50ns/div
250mv/div
250mv/div
Figure 4: HF Transientresponse with and without extension leads
Probe Loading
When you touch your probe tip to a circuit ele ment, you are
introducing a new resistance, capacita nce, and inductance into the
circuit.
Frequency and impedance of the source determine how much the
probe loads the circuit you are measuring. As the frequency of the
source starts to increase beyond 1 kHz, the input impedance of the
probe begins to decrease. The lower the impedance of the probe
relative to that of the source, the more the probe loads the circui t
under test. For a graph of frequency versus input impedance, refer to
Figure 6 on page 19.
The probe hasvirtually no loading effect on sources with relatively
low impedance andlow frequency.