https://doi.org/10.1351/goldbook.S06036
Abbreviation for standard temperature (\(273.15\ \text{K}\) or \(0\ ^{\,\unicode{x26ac}}\text{C}\)) and pressure (\(10^{5}\ \text{Pa}\)); usually employed in reporting gas volumes. Note that flow meters calibrated in standard gas volumes per unit time often refer to volumes at \(25\ ^{\,\unicode{x26ac}}\text{C}\), not \(0\ ^{\,\unicode{x26ac}}\text{C}\).
See also:
standard conditions for gases