Definition
The unit of inductance in the centimeter-gram-second (CGS) electromagnetic system of units. One abhenry equals one billionth (10⁻⁹) of a henry, which is the standard unit of inductance used in modern aviation electrical systems.
Plain English
A very small, older unit used to measure how strongly a coil of wire resists changes in electric current. It is one billionth the size of the henry, which is the unit pilots and technicians actually see today.
Context Anchor
Seen mainly in older electrical, radio, ignition, or maintenance reference material rather than in normal cockpit use.
Derivation
The prefix 'ab-' comes from 'absolute,' marking units in the older CGS electromagnetic system. So 'abhenry' literally means the absolute (CGS) version of the henry. Knowing this helps you recognize 'ab-' units (abvolt, abampere, abohm) as a family of obsolete electrical units.
Why Pilots Care
A pilot will rarely need to use abhenrys directly, but recognizing the term prevents confusion when reading older aircraft electrical or radio material.
Grounding Statement
If a coil is rated in abhenrys, the number is describing a very small amount of electrical opposition to changing current.
Intuition Check
Do not read abhenry as an aircraft part or a special kind of battery. It is only a unit of measurement for inductance.
Example Sentence 1
The textbook listed the coil's inductance in abhenrys, so the technician converted the value to microhenrys before comparing it to the avionics specification.
Example Sentence 2
Technicians converted the reading from abhenries to henries before replacing the inductor.