Physics and Engineering of Radiation Detection

A.2. Oscilloscope 747

dynamic range of such a probe is usually limited by the specifications of its active
circuitry, which for typical probes is fairly low.

Tip

To Scope

Cable (50 )Ω

Figure A.2.5: A simple passive probe.

All of the probes we have visited so far measure signals with ground as reference.
If we wanted to measure a signal that has some other reference point, we can not
use such probes. In such a situation we need the so calleddifferential probe.A
differential probe has two tips to probe the two points on the circuit. A simple
active differential probe is shown in Fig.A.2.6.

Cable (50 )Ω

+

−

Tip

Tip

To Scope

Figure A.2.6: A simple differential probe.