Determination of Viscosity of a lubricant by Redwood Viscometer?

The Redwood viscometer measures the viscosity of a lubricant by determining the time it takes for a specific volume of the fluid to flow through a calibrated orifice at a controlled temperature. The test typically uses two different redwood viscometers (Redwood 1 and Redwood 2) that operate at different temperature ranges. The viscosity is expressed in seconds, indicating how long it takes for the liquid to flow, which can then be correlated to viscosity values for the lubricant. This method is particularly useful for assessing the flow characteristics of heavier lubricants and oils.