STP (Standard Temperature and Pressure)

STP refers to a standard set of conditions for experimental measurements, to allow comparisons to be made between different sets of data. Standard temperature is 0 °C (32 °F). Standard pressure is 1013hPa or 14.696 psia. The most used are those of the International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and Technology (NIST) but there is not currently a universal standard.