STP, NTP, ATP 란?

STP [Standard Temperature and Pressure]

온도 0℃ , 압력  1bar[0.986기압] 에서의 물질(주로 기체)의 상태. 이 온도와 압력을 각각 표준온도, 표준압(標準壓)이라고 한다.

표준상태에서의 이상기체(理想氣體) 1그램 분자의 체적은 기체의 종류에 관계없이 약 22.4이다.

temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of 100 kPa (14.504 psi, 0.986 atm, 1 bar)

NTP [ Normal Temperature and Pressure.]

표준대기압 조건은 20℃, 1기압, 그리고 상대습도 65% (RH=0.65)이다

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

ATP [ Actual Temperature and Pressure.]

실제  온도와  실제 압력

 chemistry, IUPAC established standard temperature and pressure (informally abbreviated as STP) as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of 100 kPa (14.504 psi, 0.986 atm, 1 bar),[1] An unofficial, but commonly used, standard is standard ambient temperature and pressure (SATP) as a temperature of 298.15 K (25 °C, 77 °F) and an absolute pressure of 100 kPa (14.504 psi, 0.986 atm). The STP and the SATP should not be confused with the standard state commonly used in thermodynamic evaluations of the Gibbs free energy of a reaction.

NIST uses a temperature of 20 °C (293.15 K, 68 °F) and an absolute pressure of 101.325 kPa (14.696 psi, 1 atm). The International Standard Metric Conditions for natural gas and similar fluids are 288.15 K (59.00 °F; 15.00 °C) and 101.325 kPa.[2]