User's Manual

Operating Basics

P5205 Instructi on Manual

With extension leads

Without extension leads

50 ns/div 50 ns/div

250 mv/div

Figure 4: HF Transient response with and without extension leads

Probe Loading

When you touch your probe tip to a circuit element, you are

introduci ng a ne w resistance, capacitance, and inductance into the

circuit.

Frequency and impedance of the source dete rmine how much the

probe loads the circui t you are measuring. As the frequency of the

source starts to increase beyond 1 kHz, the input impe dance of the

probe begins to decrease. The lower the impeda nce of the probe

relative to that of the source, the more the probe loa ds t he circuit

under test. For a graph of frequency versus input impedance, re fer to

Figure 6 on page 19.

The probe has virtually no loading effect on sources with relatively

low impedance and low frequency.