Flash point

Japanese: 引火点 - いんかてん（英語表記）flash point

The phenomenon in which a flammable liquid or solid ignites when a flame is brought close to its surface while it is being heated is called flash, and the lowest temperature at which ignition occurs is called the flash point. In other words, the flash point is the temperature at which a liquid or solid generates vapor at its surface equivalent to the lower limit of the flammable range. At the flash point, the amount of vapor is small, so even if it ignites, it does not continue to burn, but if the temperature rises further, it will continue to burn. This temperature is called the burning point. The lowest temperature at which it ignites without a flame when heated further is called the ignition point. The flash point, combustion point, and ignition point all vary slightly depending on the test method and measurement conditions, so they are not physical constants, but they are important physical properties when it comes to handling them. For example, the flash points and ignition points of gasoline and ethanol are -42.8°C, 280°C, 11.1°C, and 422°C.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

可燃性の液体または固体を加熱しながらその表面近くに炎をもたらすときに発火する現象を引火といい，引火が起る最低温度を引火点という。換言すれば，引火点とは液体または固体が，その表面で燃焼範囲の下限に相当するだけの蒸気を発生する温度のことである。引火点では蒸気量が少いので，引火しても燃焼を継続せず，さらに温度が上昇すると燃焼を継続するようになる。この温度を燃焼点 burning pointという。さらに加熱され，炎がなくとも発火する最低温度を発火点という。引火点，燃焼点，発火点とも試験法，測定条件によって多少異なるので，物理定数ではないが，取扱い上重要な物性の一つである。たとえばガソリンおよびエタノールの引火点と発火点とは，－42.8℃，280℃および 11.1℃，422℃。

出典　ブリタニカ国際大百科事典小項目事典ブリタニカ国際大百科事典小項目事典について　情報

<<: Inca civilization - Inca civilization

>>: Cryptogam - Cryptogam