IRIS MODEL P522 APPLICATION MANUAL
detected). The
Specifications for the analog current output signal are provided in SPECIFICATIONS Figure 13.
INSTALLATION OF VIEWING HEAD
Before beginning the actual installation, determine the best location for mounting the viewing head based upon the following factors:
VIEWING HEAD CROSS-REFERENCE
OL D NUMB ER | NEW NUMB ER |
|
|
S506 | S506 |
|
|
IRX2S | S509 |
|
|
IRGS | S511 |
|
|
IRS | S512 |
|
|
FIGURE 7 - VEWING HEAD CROSS-
REFERENCE TABLE
PRESSURE
The viewing head lens will withstand 5 psi. If the lens assembly is exposed to greater than 5 psi through sight pipe, then an isolation unit must be used. An IRIS isolation unit with purge air entrance is avail- able as an accessory.
TEMPERATURE
The viewing head will withstand an ambient tem- perature to 80°C (176°F). However, the case tem-
perature of the housing must not exceed 60°C
(140°F). Purge air will help reduce conducted heat through sight pipe to flange (a plastic nipple will also help), but direct radiation can cause housing case temperature to exceed limits. If the ambient heat (direct radiation) is excessive, then a fiber optic ex- tension should be used (please refer to the IRIS Model 500 Fiber Optic System manual). This sys- tem is composed of a viewing head, a fiber optic assembly, and an amplifier module.
The model S5xx series of viewing heads have in place a sensor for sensing the internal temperature of the head. To access the reading of the viewing head temperature, press the “Reset” and the “Down” arrow key at the same time. The temperature read- ing will be displayed in the
VIBRATION
Do not install the viewing head where it could be subject to vibration. A vibrating viewing head (flicker type) can simulate flame when viewing a glowing background. Provide an antivibration mount if excessive vibrations are present.
CLEARANCE
Make sure there will be sufficient room to remove the housing for servicing (see Figure 16).
SIGHTING OF THE VIEWING HEAD
In general, the sighting of the viewing head should be parallel to the center line of the burner in the di- rection of the burner flame. This applies to both the UV type as well as the flicker type. Flicker type detectors respond to the high frequency flicker of the flame; so, in order to achieve maximum dis- crimination between burners, the near portion of the primary combustion zone should be favoured – meaning the sight pipe should be mounted as close as possible to the burner center line. The sight pipe should be aimed at the root of the flame, which radi- ates the most intense,
When sighting for a UV viewing head, you must aim for the UV zone, which is usually at the very first part of the flame root. UV radiation from most flames is restricted to a narrow region: it starts very close to the burner nozzle and does not extend out very far from the burner nozzle. You may have to angle the sighting inward toward the flame root, as shown in Figure 18.
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