What is the difference between Standard cubic meter per hour and Normal cubic meter per hour?

Answer 1

A cubic meter is a cubic meter and that is world standard. There are no non-normal cubic meters or normal cubic meters.

Scroll down to related links and look at "Conversions of volume and capacity units".

Only for gases with ideal gas behavior there is made a theoretical difference between standard cubic meters and normal cubic meters.

Everything is in formula:

p*V/T = pn*Vn/Tn

where

pn = Pressure at normal conditions (1.0133x105 Pa = 1.0133 bar)

Vn = Volume at normal conditions (Nm3)

Tn= Temperature at normal conditions (273°K)

p = Application pressure

V = Volume at application pressure

T = Application temperature

This is valid only for ideal gases and gases with ideal gas behavior.

Another answer:

Be careful when you see standard (Sm3/hr) or Normal (Nm3/hr) for the following reason:

There is a variety of alternative definitions for the standard reference conditions of temperature and pressure. STP, NTP and other definitions should therefore be used with care. It is always important to know the reference temperature and reference pressure for the actual definition used.

TYPICALLY (BUT NOT ALWAYS):

STP - Standard Temperature and Pressure - is defined by IUPAC (International Union of Pure and Applied Chemistry) as air at 0oC (273.15 K, 32 oF) and 105 pascals (1 Pa = 10-6 N/mm2 = 10-5 bar = 0.1020 kp/m2 = 1.02x10-4 m H2O = 9.869x10-6 ATM = 1.45x10-4 psi (lbf/in2)) -->Note that the earlier IUAPC definition of STP to 273.15 K and 1 ATM (1.01325 105 Pa) is discontinued.

HOWEVER, Standard can also mean, in the US system of units, as air at 60 oF (520 oR) and 14.696 psia (15.6oC, 1 ATM).

SO BE CAREFUL - standard means one thing in Europe and quite another thing in the US, which is why you need a temperature and pressure when someone says

standard.

Typically, Normal conditions means the following temperature and pressure:

Pressure = 1 ATM = 0.0 psig, and T = 25C = 298K

However, I have also seen Normal refer to the following (from http://www.engineeringtoolbox.com/stp-standard-ntp-normal-air-d_772.HTML):

NTP is commonly used as a standard condition for testing and documentation of fan capacities:

• NTP - Normal Temperature and Pressure - is defined as air at 20oC (293.15 K, 68oF) and 1 ATM ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 29.92 in Hg, 760 torr). Density 1.204 kg/m3 (0.075 pounds per cubic foot)

If you have the temperature and pressure at standard, you can convert to normal conditions using the ideal gas law:

(PV/T)2=(PV/T)1