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Selecting Transmitter Location:
Select the most suitable locations for each transmitter. Several
factors should be considered when selecting location to install the
gas transmitter. The following general suggestions should be
considered.
•
Air current: if there are fans, wind or other sources of air
movement, gases may tend to rise or collect in certain areas
of a facility. The local air currents should be assessed to aid
in selecting the sensor locations. Outdoor situation
considerations, such as prevailing winds, should be accounted
for. Air convection can often be more important in determining
gas concentrated areas than factors of vapor density.
•
Vapor Density: When there are no air currents in the area, for
gases lighter than air we suggest placing the sensor
approximately 12
”
(30 cm) above the level of a potential leak
source or near the roof in indoor installation. For gases
heavier than air, we suggest placing the sensor 12
”
(30 cm)
below the level of a potential leak source or near the floor
or ground. Gases with density equal to air or slightly greater
than air tend to rise particularly when the air currents are
present.
•
Gas emission source: as a rule, at least one sensor should be
located in close proximity to each point where leak is likely
to occur. This is particularly important when a liquid with low
volatility is being monitored.
•
Environmental factors: Consider the following in selecting the
location
(i)
Install sensors where they are protected from wind,
dust, snow, water, vibrations and shock.
(ii)
Observe
the
temperate
&
pressure
variation
surrounding the desired location. It should be within
the specified operating temperature & pressure of the
gas transmitter.
