cm3STPcmcm2scmHg

cm3STPcmcm2scmHg is not a standard scientific term, but rather a concatenation of several common measurement units used in physics, chemistry, and engineering. Interpreting it as a sequence, it can be read as cubic centimeters at standard temperature and pressure (cm3 STP), centimeter (cm), square centimeter (cm2), second (s), and centimeter of mercury (cmHg).

cm3 STP refers to a volume of gas defined under standard conditions. The cm3 (cubic centimeter) is a unit of volume equivalent to 1 milliliter. When gas volumes are reported as cm3 STP, they are often normalized to standard temperature and pressure, which in many contexts means 0°C and 1 atm (though definitions can vary by organization, with 0°C and 1 bar also encountered).

cm is a unit of length in the metric system, equal to one hundredth of a meter. cm2 is a unit of area, equal to one square centimeter or 1e-4 square meters. s is the base unit of time, the second.

cmHg, or centimeter of mercury, is a non-SI unit of pressure equal to ten millimeters of mercury. It is approximately 1.333 kilopascals (kPa) or about 0.01316 atmospheres (atm). In modern practice, pascals (Pa) or kilopascals and millimeters of mercury (mmHg) are more commonly used for pressure, but cmHg appears in older literature and some specialized contexts.

In practice, the string highlights the diversity of units used in measurements: volumes in cm3 (often related to mL), lengths in cm, areas in cm2, time in s, and pressures in cmHg. When performing calculations, all quantities should be converted to consistent SI units.