Voltage Drop Testing

Voltage Drop Testing




Voltage Drop Tests determine the resistance of an active circuit, a circuit with current flowing.

Voltage drop tests are preferred over simple resistance measurements because the power source is not removed from the circuit.

By measuring the voltage on both sides of a load, the amount of voltage consumed by the load is measured.

The voltage drops of each part of a series circuit added together must equal the power supply for that circuit while it is active.

Typical Application of Voltage Drop Testing
- Determine proper component operation.
- Active circuit continuity.
- Active circuit resistance.
- Select proper function and range of DVOM.
- Connect (+) lead to the B+ side of the circuit or component being tested.
- Connect (-) lead to the B- side of the circuit or component.


NOTE:
All consumers of the test circuit should be active during the test.
Always include ground circuit as part of voltage drop test.


DVOM display will indicate the voltage drop in the circuit tested between the DVOM leads.