The underlying concept of tracer gas testing is that a gaseous taggant (tracer) can be dispersed in
such a way that by following the movement of, and measuring the concentration of, tracer gas one can
determine airflow and contaminant movement in complex situations
The movement of a contaminant can be investigated using a localized tracer injection and sampling for
the presence of tracer at various locations. Tracer gas techniques can accurately measure the flowrate
of air or other gas in a duct, stack, or pipe when conventional flow measurement techniques are inappropriate.
Simply stated, a tracer gas is any gas that does not appear in significant concentration in and around
the area where a tracer gas test is to be performed. Additionally, the gas should be non-reactive, non-toxic,
odorless, colorless, and should be detectable by a recognized measurement technique.
Tracer gas techniques can measure air infiltration and ventilation characteristics of buildings and are usually
the only method that can be used to accurately measure the amount of outside air supplied to a building under
actual operating conditions.
Tracer gas techniques can be used to characterize and quantify the migration of contaminants within rooms or
entire buildings, to study exhaust reentrainment, and to study the consequences of real or postulated accident
scenarios involving the release of gases and/or vapors as a part of an Industrial Hygiene or Indoor Air Quality
study.
The semiconductor, nuclear power(NCS) generation,
pharmaceutical, and petrochemical industries as well as the legal community routinely
use tracer gas studies to assist with their airflow or contaminant migration studies.
