How do I tell if a Current Probe is damaged?

If a Current Probe, order code DCP-BTA, $39 was subjected to more than 0.6A, it will burn out a resistor inside the sensor. This can happen when students don't get the value they want, so they just keep increasing the current on a power supply.

Typically a blown Current Probe will still auto ID, but will read 0 A on its own and 0.6 A when connected to a circuit. There is not actually any current flowing through the probe because the sense resistor has been burned open. If you have an ohmmeter it's easy to tell if this is the case. The sense resistor is a 0.1 Ω resistor which is directly between the + and - posts. When testing a blown Current Probe with an ohmmeter, you will get an error or overload message, because it is an open circuit.

Another possible problem is that the binding post can become loose twist until the wire breaks, which will give the same symptom.

In either case, the unit can be repaired by replacing the resistor. Contact Vernier technical support to set up a repair order.