Teledyne 700 IR Series Instruction Manual page 15

(5) Maintenance access.
Density
Placement of detectors relative to the density of the target gas is such that detectors for the
detection of heavier than air gases should be located within 4 feet of grade as these heavy gases
will tend to settle in low lying areas. For gases lighter than air, detector placement should be 4-8
feet above grade in open areas or in pitched areas of enclosed spaces.
NOTE: Methane is lighter than air. Most other combustible hydrocarbon gases are heavier than
air. Compare the molecular weight, density, or specific gravity of the target gas(es) with that of
air to determine appropriate placement.
Leak Sources
The most probable leak sources within an industrial process include flanges, valves, and tubing
connections of the sealed type where seals may either fail or wear. Other leak sources are best
determined by facility engineers with experience in similar processes.
Ventilation
Normal ventilation or prevailing wind conditions can dictate efficient location of gas detectors in
a manner where the migration of gas clouds is quickly detected.
Personnel Exposure
The undetected migration of gas clouds should not be allowed to approach concentrated
personnel areas such as control rooms, maintenance or warehouse buildings. A more general
and applicable thought toward selecting detector location is combining leak source and
perimeter protection in the best possible configuration.
Maintenance Access
Consideration should be given to providing easy access for maintenance personnel.
Consideration should also be given to the consequences of close proximity to contaminants that
may foul the sensor prematurely.
NOTE: In all installations the gas detector should point straight down (refer to Figure 8: Outline
and Mounting Dimensions. Improper detector orientation may result in false readings and
permanent detector damage.
Additional Placement Considerations
The detector should not be positioned where it may be sprayed or coated with surface
contaminating substances. Painting detector assemblies is prohibited.
Although the detector is designed to be RFI resistant, it should not be mounted in close proximity
to high-powered radio transmitters or similar RFI generating equipment.
When possible, mount the detector in an area void of high wind, accumulating dust, rain, or
splashing from hose spray, direct steam releases, and continuous vibration. If the detector cannot
be mounted away from these conditions then make sure the Teledyne Oldham Simtronics Harsh
Environment Splashguard accessory is used (PN DET-943-002273-000).
NP700IRIMEN
Revision E.0
INFRARED GAS DETECTOR FOR COMBUSTIBLE AND CO
700 IR Series
2
GASES
USER MANUAL
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