Definition
A cockpit gauge that displays the electrical current, in amperes, flowing through the propeller anti-ice system. The reading allows the pilot to verify that the heating elements bonded to the propeller blades are drawing the expected current and therefore producing heat to prevent ice from forming.
Plain English
A small gauge that shows whether electricity is actually flowing to the heaters on the propeller blades. If the needle reads in the normal range, the prop heaters are working. If it reads zero or out of range, something is wrong with the system.
Context Anchor
Seen on aircraft equipped with electrically heated propeller anti-ice, especially during icing-condition checks and while monitoring the system in flight.
Derivation
Ammeter comes from 'ampere' (the unit of electrical current, named after French physicist André-Marie Ampère) plus '-meter' (a device that measures). So an ammeter measures amperes. Adding 'prop anti-ice' simply tells you which circuit this particular ammeter is monitoring.
Why Pilots Care
Confirms the system is receiving power and operating within the expected current range so ice does not accumulate on the blades.
Intuition Check
Do not read this as a gauge that shows how much ice is on the propeller. It shows electrical flow to the propeller anti-ice system; the correct reading range depends on the aircraft.
Example Sentence 1
Before entering the cloud layer, she switched on the prop anti-ice and checked the prop anti-ice ammeter to confirm the heaters were drawing current.
Example Sentence 2
In flight through light icing the pilot monitored the prop anti-ice ammeter to ensure the blades stayed clear.