normal atmospheric temperature
NTP-Normal Temperature and Pressure. NTP is commonly used as a standard condition for testing and documentation of fan capacities: 1  NTP-Normal Temperature and Pressure-is defined as air at 20oC (293.15 K, 68oF) and 1 atm (101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 29.92 in Hg, 407 in H2O, 760 torr).ote that the earlier IUAPC definition of STP to 273.15 K and 1 atm (1.01325 105 Pa) is discontinued. 1 Pa = 10-6 N/mm2 = 10-5 bar = 0.1020 kp/m2 = 1.02x10-4 m H2O = 9.869x10-6 atm = 1.45x10-4 psi (lbf/in2). Standard volume of 1 mole of an ideal gas at STP is 22.4 liters.