Teledyne Hastings Instruments

	Home Flow Products Vacuum Products Customer Support Information Desk

Find Sales Representative

Why do I need to specify standard conditions (STP) when ordering my Hastings mass flow controller?

Mass flow measures mass not volume. Familiar mass flow rate measurements are in lb/hour or kilograms/minute. However, we are accustomed to measuring gas flow in “volumetric” terms (liters/minute) so the density (grams/liter) of the gas is used to covert mass into volume. When we choose a density, the temperature and pressure must be known.

For a more detailed explanation click here