The open cup flash point tester is mainly used to measure petrol engine lubricating oil, diesel engine lubricating oil, compressor oil, refrigeration oil, turbine oil, gear oil, mechanical oil, etc.
The closed cup flash point tester is mainly used to determine the lubricating oil of No. 8 turbojet engine, No. 20 aviation lubricating oil, high-speed machinery oil, transformer oil, instrument oil, oil, etc.
The use of open flash point or closed flash point mainly depends on the properties and usage conditions of the oil. For most lubricants, especially those used in non enclosed machinery or under low temperature conditions, open flash points are used. When used in sealed containers, high temperatures are often generated due to various reasons (such as overheating, short circuit of current, arc action, etc. caused by high-speed or other reasons), which may cause the formation of decomposition products in lubricating oil. When mixed with air, there is a risk of fire and explosion. Closed flash points, such as transformer oil, are used.