Which property is NOT typically checked during product quality assessment in a refinery?

During product quality assessment in a refinery, multiple properties are routinely measured to ensure that the products meet specific quality standards. Among these, viscosity, density, and octane levels are critical parameters that directly affect the performance and suitability of fuels and other products.

Viscosity is essential because it affects how a liquid flows, which is particularly important for fuel dispensing and engine operation. Density is another key property, impacting the energy content and pricing of fuels, as well as ensuring proper blending of different components. Octane levels are crucial for gasoline, influencing engine performance and preventing knocking.

Color, while it may provide some information about the presence of contaminants or the general appearance of a product, is not a standard indicator of fuel quality or performance. It does not provide the kind of technical data that the other properties do, making it less relevant in the stringent assessments typical in refinery settings. Hence, color is considered the property that is not typically checked during product quality assessments in a refinery.