Detcon CX-DM - Manual (Page 8)

Model CX-DM
11. The CXT-DM may be used as an oxygen deficiency sensor; the CXT-DM must not be used for
detecting oxygen concentrations expected to be greater than 21%
12. The CXT-DM must only use gas sensor cell model 371-xxxx00-yyy. No other gas sensor shall be
used.
2.2 Sensor Placement
Sensor location is critical to the overall safe performance of the product. Confirm that the following five
factors are verified during sensor placement.
1. Density of the gas to be detected
2. Most probable leak sources within the industrial process
3. Ventilation or prevailing wind conditions
4. Personnel exposure
5. Maintenance access
Density
Sensor placement should be relative to the density of the target gas. For the detection of heavier than air gases,
sensors should be located within 4 feet of grade since heavy gases typically settle in low lying areas. For gases
lighter than air, sensor placement should be 4 to 8 feet above grade in open areas or in pitched areas of
enclosed spaces.
Leak Sources
The most leak sources in an industrial process are flanges, valves, and tubing connections 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 sensors in a manner
where the movement 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. Selecting sensor location should combine leak source
and perimeter protection in the best possible configuration.
Maintenance Access
Consideration should be given to providing easy access for maintenance personnel and the consequences of
close proximity to contaminants that may cause the sensor to wear prematurely.
NOTE
In all installations, the gas sensor should point straight down. Improper sensor orientation
may result in false readings and permanent sensor damage.
CX-DM Instruction Manual Rev. 1.3 Page 4 of 40