Standard cubic centimeters per minute (SCCM) is a unit used to quantify the flow rate of a fluid.
These standard conditions vary according to different regulatory bodies.
One example of standard conditions for the calculation of SCCM is
= 1.01 bar (14.72 psia) and a unity compressibility factor
= 1 (i.e., an ideal gas is used for the definition of SCCM).
[2] This example is for the semi-conductor-manufacturing industry.
For conversion purposes, 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,
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),[3][4] where
is density at some standard conditions, and an equation of state such as with
the fluid compressibility factor, and
the universal gas constant.
units of measurement and their conversion between square brackets one obtains where
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,[5] 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
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 To convert 1 SCCM to kmol/s 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.