In petroleum product testing, which instrument is specifically used to determine the colour of light petroleum fractions and refined products?

Introduction:
The colour of light petroleum products is a quality indicator and is measured using standardized instruments. Correct test method selection ensures comparable, specification-grade results.

Given Data / Assumptions:

• Product type: light petroleum fractions (e.g., kerosene, jet, gasoline blending components).
• Objective: identify the correct instrument for colour determination.

Concept / Approach:
For light, nearly water-white petroleum products, the Saybolt colour scale and its dedicated instrument, the Saybolt chromometer, are standard. Darker products often use ASTM (D1500) colour comparators, but the question’s emphasis is on light fractions where Saybolt is conventional.

Step-by-Step Solution:
1) Identify target measurement: product colour.2) Map to standard instruments: Saybolt chromometer for light product colour.3) Exclude unrelated test apparatus.

Verification / Alternative check:
Specifications for aviation turbine fuel and kerosene frequently reference Saybolt colour for appearance; standard lab manuals align on the Saybolt chromometer for this range.

Why Other Options Are Wrong:
Colour comparator: Generic term; ASTM D1500 comparators are used for darker products.Cleveland open cup apparatus: Measures flash point, not colour.None of these: Incorrect because the Saybolt chromometer is appropriate.ASTM D86 distillation unit: Used for volatility curves, not colour.

Common Pitfalls:
Confusing colour determination with clarity/appearance checks or with unrelated tests like flash point or distillation leads to wrong instrument selection.

Final Answer:
Saybolt chromometer