Design And Research Of Petroleum Products Closed-cup Flash Point Tester

Petroleum Products Closed-cup Flash Point (PPCFP) is one of the most important characters of petroleum products. PPCFP testing has a deep meaning, because it counts for much to the petroleum's storage and transport, also it counts for much to the environment protection and petrochemicals production. As a scientific instrument, good stability and high precision are required to the PPCFP tester.The design and research of PPCFP tester based on Atmega 128 is discussed in this paper. According to nation criterion of petroleum products determination of flash point with closed-cup method (GB/T261), an entire auto controlled intelligent PPCFP testing system is designed. This system has functions of petroleum temperature measuring, PPCFP testing, heater control, keyboard input and LCD display, RS-232 and RS-485 serial communication and so on. Hardware circuit design and software programming have been done to realize all these functions. Through the analysis of existing PPCFP testers, it's found that petroleum temperature measuring is the primary factor that affects tester's quality. So temperature measuring method is researched as an emphasis. Taking advantage of segmented linearization method combined with plus revision and scale revision, the new method has character of high precision. Now the testing results of native PPCFP testers are unstable, so an improved method called Area flashing method is used to distinguish flashing with non-flashing and fake flashing. The result of experiment indicated that the improved method of PPCFP testing accords with GBAT261.Monitor and control software of upper machine which matches PPCFP tester is developed by Visual Basic 6.0. It is used to set menu of PPCFP tester, display various data and curves. In addition, it is used to print testing report and query database. This software extends functions of PPCFP tester. It's convenient to the users.