8. Move the emitter down until the light
turns off.
9. Note the angle.
10. Move the emitter to the middle of the
two angle readings.
11. Tighten the emitter and receiver
hold-down bolts.
12. Re-inspect for receiver LED.
5.2 Instrument Failure
The FAIL status, which activates
warnings at both the remote status display
and at the computer, can be caused by three
conditions:
1) Sensor Blockage-when the sensors
are blocked by dirt, ice, or snow for
several minutes or when a vehicle
remains in the portal too long.
2) Hi Background - A radiation sensor
indicates radiation levels above the
normal limits.
3) Lo Background - A radiation sensor
indicates radiation levels below the
normal limits.
The most common failure mode is the
sensor blockage, so checking the sensors for
blockage should be the first response.
(Refer to more details later in this section.)
Once the blockage is corrected, the reset
button should be pressed and held for three
seconds to reboot the system and establish a
new background.
The Hi or Lo Background conditions
usually indicate detector failure, although
the Hi Background condition could be
associated with some external radiation
source, such as an X-ray truck. If this is the
case, remove the radiation source, and
reboot the system. If it is determined that no
external radiation source is causing the Hi
Background, then the detector should be
disabled (see section 10. “Setting
Parameters”), and technical support should
be called. Disabling the detector allows the
system to run with the other working
detectors.
SENSOR BLOCKAGE
1. Check emitter for proper operation.
(Refer to section 5.1 to identify the sensor
emitter.) Its LED should be on and stay on.
If not, it has a problem and technical support
should be called.
2. Check that there is not a vehicle or
other object in the lane. If there is, remove
it. 3. Check the pinhole on the emitter.
Clean and/or remove any blockage.
4. Check lenses on emitter and receiver.
If lenses are dirty, clean them with a clean
damp cloth. If they are iced over, use a
commercial de-icer and then clean them.
5. Check alignment of sensors. (Refer
to SENSOR SETUP AND ALIGNMENT,
Section 5.1).
6. Check receiver for proper operation.
(Refer to text in section 5.1 to identify the
sensor receiver.). Its LED should be on and
stay on until an object passes through the
lane. If steps 1 through 5 have been
completed and there is still a problem,
technical support should be called.
BACKGROUND TOO HIGH
1. Check that VACIS source is not too
close to portal.
2. Use a portable radiation instrument
to determine if a foreign source of radiation
is present. (A person who has recently
undergone a medical procedure using
radiopharmaceuticals can be an unknowing
radiation source.)
3. Reinitialize instrument. (When portal
is clear, hold reset button 3 seconds.)
4. If failure persists, contact Supervisor.
BACKGROUND TOO LOW
1. Reinitialize instrument. (When
portal is clear, hold reset button 3 seconds.)
2. If failure persists, contact Supervisor.