metering pin[′mēd·ə·riŋ ‚pin]
A flow-control device in a metering orifice used to vary the amount of fluid that can flow through it. The shape or contour of a metering pin determines the amount of fluid that can flow with the pin in any position other than fully in or fully out. It is used in shock absorbers in the undercarriage system and helps restrict the passage of fluid from one chamber to another, thus cushioning the landing impact. Also used in fuel-control systems.