Design Of A Cooling Characteristics Testing System For Quenching Media Based On Virtual Instrument

The project is focused on design and development of testing system for quenching media, particularly building an applicable testing system with Virtual Instrument. With the development of testing technology to be much faster, more automotive, more intelligent and more integrated, we set up a complete set of architecture with PCIM-Series Data Acquisition card and a GUI development platform-LabVIEW, toimplement the system, according the standard IFHT-THERMAICOUPEPROBE .Namely, modularization in programming is used to divide the system into several individual function blocks and each function is implemented by a block. The master block (interface panel) controls the other blocks. Combined with the modularization in programming and corresponding hardware, the testing system is designed.In hardware design, both the quench media's cooling characteristics and the ambient temperature are acquired to actualize dynamic cold junction compensation (CJC) for K-type thermocouple. Besides, a signal conditioning circuit is designed to linearly amplify and denoise the signal to acquire an exact and reliable voltage signal. In software design, many functions, such as data acquisition, data pre-process, scale conversion, data process, display and storage, are realized by the engineering GUI software, with modularization in programming. The interface is user-friendly and its manipulation is very easy. Additionally, digital filter from LabVIEW is used to denoise voltage from K-type thermocouple.The data acquisition hardware, including all the testing equipment, and the data process software based on Windows are linked to set up the testing system of cooling characteristics for quenching media, of which the data acquisition & process is the nucleus. The quenching experiments of brine with different concentration prove temperature in the center of the probe and its quenching velocity to assess the cooling capacity of quenching media is faster, more exact and more real-time. Also, the result can be repeated time after time and the system can be used to different quenching medias.