Setup
Page 218 OmniTrax Product Guide
Sensor verification testing
Once the system is calibrated and setup, test the settings by performing multiple crossings over
the full length of detecting cable. If possible, use both large and small test subjects, moving at
different speeds. Connect a computer running the UCM during the tests and record magnitude
response plots. Pay careful attention to any cable bypasses. Test the cable segments and zone
settings to ensure alarms are reported in the correct zones. In addition, verify that the inputs and
outputs function as intended. Depending on the test results, either put the system into service, or
adjust the detection parameters and zone layouts.
Locating the detection field centerline
Once the ground surface is fully restored, it can be difficult to precisely locate the detection field
centerline. However, precise location is critical should you need to recalibrate the processor by
updating the sensitivity profile. The best method for locating the detection field centerline is to
obtain a good quality cable locater. Use the cable locater to mark the cable path of both (OC2,
SC2) cables or the single cable (SC1). Mark the centerline between the cables (directly above
SC1) and follow the marks to recalibrate the processor.
If a cable locater is not available, you can locate the detection field centerline by doing crossings.
For this procedure, you will require an accurate site plan, two way radios, marker paint, a walker
and a maintenance technician running an OmniTrax magnitude response plot on the UCM.
1. Use the site plan to determine the start point of the detection zone.
2. Have the walker stand well outside the detection field and start the Magnitude plot.
3. Have the walker do a very slow crossing at the start point. The walker must cross the detection
field perpendicular to the cable path.
4. Stop the walker when the signal reaches the peak.
5. After the second crossing have the walker mark the centerline with the paint.
6. Have the walker move outside the detection field and proceed down the cable.
7. Repeat the crossings at 10 m intervals over straight cable sections and at 2 m intervals around
corners, marking the ground at each crossing point.
8. Once you have marked the ground over the full length of cable, return to the start point and
conduct a sensitivity profile (see OmniTrax calibration - Sensitivity Profile and Transmitter
Power on page 197).
CAUTION OmniTrax sites which experience significant seasonal variations in
climate require additional sensor verification testing. Seasonal
variations that can affect system performance include ground freezing,
ground thawing, and major changes in the moisture content of the soil
(i.e., periods of heavy rain and periods of hot dry weather). Heavy rain
can also cause significant soil erosion. Always retest the OmniTrax
system following major seasonal changes in the weather, and
recalibrate the sensor if required.
Note There is always a delay between the actual UCM reading and when the
walker is informed to stop. Have the walker recross the detection field
very slowly to confirm the location of the peak response.
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