sccm

   , scfm, scfh, scfd, scim (etc.)

   symbols for "standard cubic centimeters per minute", "standard cubic feet per minute", "standard cubic feet per hour", "standard cubic feet per day", and "standard cubic inches per minute." Many similar abbreviations are in use. These are units of flow rate for gases, and the term "standard" indicates that the flow rate assumes a standard temperature and a standard pressure of 1 atmosphere. There is some variation in the standard temperature. For natural gas, the petroleum industry uses a standard temperature of 60 °F (15.6 °C). For air flow, the standard temperature is sometimes 32 °F (0 °C) or 68 °F (20 °C) and a standard relative humidity must also be specified. The actual air flow is often designated with an "a" instead of an "s", as in "acfm".