User manual

Operator Information

Insertion Impedance

When you insert

a conductor into the probe, you add impedance to the circuit you

are measuring. This additional impedance affects signals; this is particularly

important if you are measuring fast rise times. The equivalent circuit with

additional impedance introduced by the P6022 is shown below.

Figure 3: I

nsertion impedance of the probe

Minimizing Loading Effect

To minimize the loading effect of the probe, clamp it at the low or ground end

of a comp

onent lead when possible. This method also minimizes noise or stray

signal interference.

Increasing Probe

Sensit

ivity

You can increase the current sensitivity of the probe by increasing the number

of time

s a conductor passes through it. For example, if the c onductor loops

through the probe twice (a two-turn primary winding), the secondary current is

doubled, because the ratio of current in a transformer is inversely proportional

to the turns ratio.

For example, suppose you set the termination sensitivity to 1 mA/mV and the

oscilloscope vertical scale to 10 mV/division. Ordinarily, this would result in the

equivalent of 1 X 10, or 10 mA/division. However, if the conductor is looped

through the probe twice, the vertical scale is divided by two, resulting in the

uivalent of 5 mA/division.

Looping the conductor twice effectively doubles vertical sensitivity; however,

pedance from the probe winding is also reﬂected into the circuit being

measured. This impedance varies as the square of the number of loops. This

additional impedance affects signals; this effect is particularly important when

you are measuring high-frequency current waveforms or waveforms with fast

rise times.

P6022 Instruction Manual 7