psychrometric chart this psychrometric chart use ifc-67 equation for water property calculating, and treat air as ideal gas. so this chart can be used in more large range and are more precise. * metric units(si) and english units(i/p) support. * eastern style and western style chart support. * angle reference of process line ratio for enthalpy-humidity and sensible-total heat. * zoom in, zoom out chart by rolling mouse wheel, and pan chart by pressing middle mouse button and moving mouse. * chart toolbar for easily processing chart copy, export, print, pan, zoom, redraw and style selection. * save and load data function for each data input grid, this is convenient and not need to input data every time restart program. * option for saving all input data to disk before exit and load them when restarted next time. * english and simplified chinese language support. * export chart to disk file as jpeg, bitmap, wmf(windows metafile format) or emf(enhanced windows metafile format) format. * copy chart to clipboard as wmf or bitmap format. * print function, aspect ratio can be adjust by moving chart boder. * moist and bulb temperature axis range can be changed. * ambient altitude range from 0 to 40km, ambient pressure 0~25bar. * illustrate dry bulb temperature, humidity ratio(or absolute humidity, moist content), constant relative humidity, constant enthalpy, constant specific volume, and constant wet bulb temperature. duct calculator: * calculate air and liquid duct. * calculate round and rectangle cross section duct. * calculate duct flow resistance, environmental heat exchange, and adiabatic effect. * save and load input data from disk.