The term "combustion point" refers to the temperature at which a material will fire and burn for at least 5 seconds. It is a temperature higher than the flash point (or flash point), which may start (if triggered) the combustion of the vapors of the material under consideration.
The device used is usually called "Cleveland" or COC ("Cleveland Open Cup"), and has an application temperature between 79 ° C and 400 ° C.
In a cup, the sample to be tested (bitumen, lubricating oils, soaps) is heated to a temperature of about 17 ° C per minute until the temperature reaches the temperature near the presumed flame point (flash point), and the heating gradient is reduced to 5.5 ° C / min; a flame generated by combustion of methane or butane gas 5 mm high lambies the top edge of the cup through its center, the flame passes with a uniform motion within the prescribed time of 1.5 seconds along the diameter of the cup. The flame passes every three degrees increment of the sample temperature, each time in the opposite direction (every "exposure" of the flame on the cup takes place every three degrees in the opposite direction to the previous one as this flame is at the end of a swinging arm that "overflows" the cup itself.
When the combustion air and gas mixture released from the heated sample flashes visibly, but this lightning is not sustained by a flame for at least 5 continuous seconds, the flash point flash point is observed but is considered less reliable of the one obtained through the Pensky-Martens Device. In fact, unlike the latter, using a closed cup with a shutter, this first flash may have been affected by the open cup that may be uncontrolled by the air / combustion mixture due to air currents.
The heating gradient remains at 5.5 ° C / min as well as the sample exposure interval at the flame: when the sample visibly ignites, sustaining a self-combustion for at least 5 seconds, the last sample temperature measured before the flame exposure is considered as a focal point. Voices correlateemodify wikitesto
wiki
