Which instrument is used to measure viscosity of oil in aviation maintenance?

Which instrument is used to measure viscosity of oil in aviation maintenance?

• A. Hydrometer
• B. Thermometer
• C. Viscosimeter
• D. Saybolt Universal Viscometer

Answer: (D)

Measuring viscosity in aviation maintenance relies on a flow-based standard so results are consistent with aircraft specifications. The Saybolt Universal Viscometer is the instrument used because it provides a defined, repeatable method for viscosity testing of oils and lubricants. It works by measuring how long a fixed volume of oil takes to flow through a calibrated capillary under gravity at a specified temperature, giving a value in Saybolt Universal Seconds. This standardized approach is essential for comparing results across labs and ensuring lubricants meet the exact requirements for performance and safety. Other options don’t fit as well: a hydrometer only measures density, not flow resistance; a thermometer only measures temperature; and a viscometer is a general term, but the Saybolt Universal Viscometer is the specific, widely adopted instrument used in aviation for oil viscosity.

Measuring viscosity in aviation maintenance relies on a flow-based standard so results are consistent with aircraft specifications. The Saybolt Universal Viscometer is the instrument used because it provides a defined, repeatable method for viscosity testing of oils and lubricants. It works by measuring how long a fixed volume of oil takes to flow through a calibrated capillary under gravity at a specified temperature, giving a value in Saybolt Universal Seconds. This standardized approach is essential for comparing results across labs and ensuring lubricants meet the exact requirements for performance and safety.

Other options don’t fit as well: a hydrometer only measures density, not flow resistance; a thermometer only measures temperature; and a viscometer is a general term, but the Saybolt Universal Viscometer is the specific, widely adopted instrument used in aviation for oil viscosity.