Flash point and fire point and its significiance:

• Flash point can be defined as, the temperature at which the oil gives out enough vapours that ignite for a moment when a small flame is brought near it.
• Fire point can bde defines as, the temperature at which the oil gives out enough vapours which burn continuously at least 5 seconds when a small flame is brough near it.
• The flash and fire points are very important properties of an oil, because these help in knowing the highest temperature upto which an oil can be used as a lubricant.
• These constants are usually determined by using Pensky-Marten's flash point apparatus.

Significiance:

• A lubricating oil selected for a job should have a flash point which is reasonably above its working temperature. This ensures safety against fire hazards during the storage, transport and use of the lubricating oil.
• It is also useful for identification and detection of contaminants in the oil.