Petroleum product testing — gasoline flash point determination For motor gasoline (flash point typically below 50°C), which laboratory apparatus is specified to determine the flash point in the low range?
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AAbel apparatus
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BPensky–Martens apparatus
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CSaybolt chromometer
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DNone of these
Answer
Correct Answer: Abel apparatus
Explanation
Introduction / Context:Flash point is the lowest temperature at which vapors above a liquid ignite momentarily upon exposure to a test flame. For volatile fuels like gasoline, low-range closed-cup methods are required to capture the early onset of flammable vapor formation safely and reproducibly.
Given Data / Assumptions:
- Product: gasoline (high volatility; very low flash point).
- Methods differ by temperature range and volatility.
- We are concerned with flash points below 50°C.
Concept / Approach:The Abel closed-cup apparatus is designed for determining low flash points (sub-ambient to around 65°C) and is historically specified for highly volatile products. Pensky–Martens is commonly used for higher flash point fuels like diesel and lubricants, not for gasoline.
Step-by-Step Solution:Identify volatility of gasoline → very high; requires low-range closed-cup method.Match to apparatus: Abel is a low-temperature, closed-cup method appropriate for flash point < 50°C.Therefore, Abel apparatus is correct.
Verification / Alternative check:Standards and handbooks align Abel (or Tag closed cup) with low flash liquids; Pensky–Martens targets higher flash products.
Why Other Options Are Wrong:
- Pensky–Martens: better for diesel, furnace oil (higher flash), not gasoline.
- Saybolt chromometer: measures color/viscosity characteristics, not flash point.
- None of these: incorrect since Abel is appropriate.
Common Pitfalls:
- Using open-cup methods or high-range apparatus for gasoline, giving unsafe or misleading results.
Final Answer:Abel apparatus