Tektronix TCP300A, User Manual

Page: 52 / 82

Reference Notes
Increasing Sensitivity
If you are measuring DC or low-frequency AC signals of very small amplitudes,
you can increase measurement sensitivity of your Current Probe by winding
several turns of the conductor under test around the probe as shown. The signal is
multiplied by the number of turns around the probe.
WARNING. To avoid injury or loss of life, do not put more than one uninsulated
conductor at a time in the probe jaws. An uninsulated conductor is de fi ned as any
conductor without insulation or without insulation rated for the voltage present
on the conductor under test.
When viewing the signal on the oscilloscope screen, divide the displayed
amplitude by the number of turns to obtain the actual current value. For example,
if a conductor is wrapped around the probe
fi ve times and the oscilloscope shows
a reading of 5 mA DC, the actual current fl ow is 5 mA divided by 5, or 1 mA DC.
NOTE. Winding multiple turns around the probe increases insertion impedance
and reduces the upper bandwidth limit of the probe.
Figure 18: Increasing probe sensitivity
34 TCPA300/400 Ampli fi ers and TCP300A/400 Series Current Probes User Manual