Model IR5500
18
fault, depending on fault delay settings. Put the magnet on the upper right edge
of the display over the GM logo. The display will change from 0 to rst, ---, SE,
in, and Pct or AJ. To align the system using AJ, refer to the Appendix. To align
the system using Pct, remove the magnet when Pct appears. Apply the magnet
when Pth appears. Select the units for the path length, enter the path length
(LEn), and whether or not there is an attenuator on the Source (nAt/At, for 5-
30m range systems only), whether or not there is a visible light filter on the
Source (nLF/LF), and Fi to finish the Pth menu. The path length entered (LEn)
should be accurate to within ± 5% of the actual distance. The Receiver will
display a number that is a percent of expected signal level. Aim for 100 percent
or higher. The minimum acceptable percent is 80. Below 50, the alignment
fault F20 will be set.
5. At the Source, lightly tighten the front fine adjust screw until it bottoms out
against the internal tilt lever. Slowly make a small turn to tighten the screw and
lower the front of the Source. Wait a few seconds for the signal level number at
the Receiver to settle. Continue making small turns, waiting after each turn for
the signal level number to settle. Once the signal level number begins to
decline, back out the front fine adjust screw until it is flush with the assembly
surface. Lightly tighten the back fine adjust screw until it bottoms out, and then
slowly make a small turn to further tighten it. Wait a few seconds for the signal
level number to settle. Continue until the signal level reaches its maximum and
begins to decline. Back out the back fine adjust screw.
6. Secure all four M6 mounting screws, tightening them gradually and alternately in
a crisscross pattern to minimize change in alignment. Verify that signal level is
reduced by 10% or less (increase of any amount is acceptable).
To complete
alignment, all four M6 mounting screws and the 24 mm nut of the pan/tilt
assembly must be fully tightened and secure
.
7. With the Source secure, repeat steps 3 through 6 for the Receiver. The Pct
should be at least 80 percent. Aim for 100 percent or higher.
8. Once adjusts are done and the signal level has been maximized, put the
magnet on the upper right edge of the display to exit alignment mode. The unit
will display a flashing AC and begin zeroing the gas reading. Once zeroing is
complete, the unit will display 0C, followed by the gas concentration.
To
complete alignment, 0C must be displayed.
With all screws secured on both
units, once 0C is displayed, system alignment is complete.
3.7.4 Response
Test
After initial alignment, a test of the IR5500 should be carried out using the Test Gas
Films for methane or propane (part numbers 329083-1 or 329084-1, respectively).
Follow the instructions on the films.
3.7.5 Visible Light Filter
One of the ModeI IR5500’s configurations is equipped with a visible light filter
(Figure 7). Such configuration can prove useful in installations where an intermittent
light beam is considered disruptive to surrounding operations. A visible light filter
blocks light in the visible portion of the electromagnetic spectrum, allowing the
instrument to detect and measure hydrocarbon gas concentrations without the
attendant effects of flashing light.
