Standard cubic centimetres per minute

Standard cubic centimeters per minute (SCCM) is a unit of flow measurement indicating cubic centimeters per minute (cm³/min) in standard conditions for temperature and pressure of a given fluid. These standard conditions vary according to different regulatory bodies. One example of standard conditions for the calculation of SCCM is formula_1 = 0  °C (273.15 K) and formula_2 = 1.01 bar (14.72 psia).
SCCM is a measure of molar flow rate (e.g., kmol/s) and in spite of its name it must not be confused with a measure of volumetric flow rate, formula_3, nor with a measure of mass flow rate, formula_4. However, it is useful to think of one SCCM as the mass flow rate of one cubic centimeter per minute of a fluid, typically a gas, at a density defined at some standard temperature, formula_1, and pressure, formula_2.
To convert one SCCM to the measure of mass flow rate in the SI system, kg/s, one relies in the fundamental relationship between mass flow rate and volumetric flow rate (see volumetric flow rate),
where formula_8 is density at some standard conditions, and an equation of state such as
with formula_10 being the fluid molecular weight, formula_11 the fluid compressibility factor, and formula_12 the universal gas constant. By including in the above relationship between formula_4 and formula_3 units of measurement and their conversion between square brackets one obtains
where formula_4 is in formula_17, formula_8 in formula_19, and formula_3 is in formula_21. Thereafter, by replacing formula_8 with the above equation of state one obtains
Using this last relationship, one can convert a mass flow rate in the more familiar unit of kg/s to SCCM and vice versa with
and 
With this conversion from SCCM to kg/s, one can then use available unit calculators to convert kg/s to other units, such as g/s of the CGS system, or slug/s.
Based on the above formulas, the relationship between SCCM and molar flow rate in kmol/s is given by
and 
For some usage examples, consider the conversion of 1 SCCM to kg/s of a gas of molecular weight formula_10, where formula_10 is in kg/kmol. Furthermore, consider standard conditions of 101325 Pa and 273.15 K, and assume the gas is an ideal gas (i.e., formula_30). Using the unity bracket method (see conversion of units) one obtains:
Considering nitrogen, which has a molecular weight of 28 kg/kmol, 1 SCCM of nitrogen in kg/s is given by:
To do the same for 1 SCCM of helium, which has a molecular weight of 4 kg/kmol, one obtains:
Notice that 1 SCCM of helium is less in kg/s than one SCCM of nitrogen.
To convert 50 SCCM of nitrogen with the above considerations one does
A unit related to the SCCM is the SLM or SLPM which stands for Standard litre per minute. Their conversion is 
and
Another unit is the SCFM which stands for standard cubic feet per minute.
Yet another unit related to SCCM (and SLM) is the PCCM (and PLM) which stands for Perfect Cubic Centimeter per Minute (Perfect Litre per Minute). One PCCM is one SCCM when the gas is ideal. In other words, one PCCM is exactly the same as one SCCM if and only if formula_37 in the above relationships.