how about a calculator that allows you to interpolate data from tables.
1. specify the pressure and the program returns the saturation temperature, enthalpy and entropy
2. specify any of the two: temperature, pressure, enthalpy, entropy, and the program returns the other two values and also state the state of the steam
3. may return other data such as specific volume, density, etc
it would be nice if the calculator supports steam, ammonia, air, co2, n2 and other common refrigerants.