Steam tables and equations, extended by direct experiment to 4,000 lb./sq. in. and 400°C

Abstract The original Steam Tables and Equations published in 1900 represented the first thermodynamically consistent system devised for the tabulation of the properties of water and steam. They were based on direct experimental measurements by the following methods, which were specially devised for the purpose:— (1)The adiabatic relation between P and T for dry steam was obtained by direct observation of its changes of temperature in adiabatic expansion and compression over the range 200° to 800° F. With a very sensitive platinum thermometer, thus eliminating a variety of errors to which the old PV method was liable. Thus results showed the adiabatic equation to be of the simple form, P/T13/3 = constant, (1) and proved that the specific heat of steam at zero pressure, denoted by S0, must be very nearly constant and equal to 0·477, or 13R/3 over this range, assuming that steam approximated to the ideal state represented by the gas equation P(V ‒ b) = RT at low pressures.