Oscilloscope Current Probe

Current probes are often needed to enable an oscilloscope to measure current - they use different techniques to those of the more familiar voltage probe.

Oscilloscope Tutorial Includes:
Oscilloscope basics Oscilloscope types Specifications USB vs bench-top scope How to use an oscilloscope Scope triggering Oscilloscope probes Oscilloscope probe specifications

Scope types includes: Analogue scope Analogue storage scope Digital phosphor scope Digital scope USB / PC scope Mixed Signal Oscilloscope MSO

Oscilloscope current probes can enable oscilloscopes to measure current and thereby extend their use beyond just that of measuring voltage.

There may be many instances where a scope current probe can come in useful - anywhere that t is necessary to measure the current rather than the voltage. Sometimes the current can be measured by [lacing a small resistor inth e line and measuring the voltage across it, but this has its own drawbacks. The best option is to use a scope current probe as this will directly measure the current with less disturbance of the circuit.

Scope current probe format

The oscilloscope current probe is manufactured so that it can be clipped around a conductor. Normally there is a spring loaded clip that enables the scope probe to be swiftly clipped around the cable.

The hole in the probe that clips around the cable under test can be seen on the right of the main probe body.

Close up of the cable camp on the oscilloscope current probe

Operation of a scope current probe

Current probes sense the current flowing through a conductor and convert it to a voltage that can be viewed and measured on an oscilloscope.

Sometimes using the maths functions on a scope along with a voltage measurement on another channel it is possible to measure power, as well as looking at the phase differences.