Doc No. 105408 Rev C, RMLD-CS Operator Manual
RMLD-CS
Operator’s Manual
Manual
© 2021 Heath Consultants Incorporated. All rights
reserved.
56
Surveying with the RMLD-CS
Re
fer to your company’s specific training and procedures for being qualified for leak surveying.
In order for the RMLD-CS to detect a gas leak, three conditions must be met:
1.
The gas plume concentration and size must be greater than the minimum sensitivity of the
instrument.
2.
The infrared beam must pass through the plume.
3.
The background target (i.e., ground, building, etc.) has to reflect the infrared beam back.
Several factors influence the gas plume size and concentration. First, very low flowing leaks may produce
small to non-measurable plumes. Also, surface types such as concrete will spread the leak and create spot
leaks through surface cracks and holes. Weather conditions like high winds and higher temperatures will
cause the plume to dissipate faster. The operator must consider these factors and their effects throughout
the survey. Consideration also must be taken for heavy rain and moisture in the soil that could change the
spread of gas and venting conditions. The same applies to frost conditions in the winter.
The most important aspect to using the RMLD-CS is the proper control and aiming of the infrared beam.
The first thing you will need to learn when surveying with the RMLD-CS is to control the aiming of the laser
and rate of sweeping. Radical or abrupt motion may cause the RMLD-CS to give false detections due to
rapidly changing distance or background that the laser detects. Radical or abrupt motion may cause the IR
beam to not thoroughly scan the area.
Here are a few tips for surveying along the main:
•
Use a smooth sweeping motion.
•
Keep the beam pointed out 15 to 20 feet. This allows for the beam footprint on the ground to
be large enough to provide good coverage, and control over the path of the beam.
•
Scan service tap and valve areas as you approach them.
•
Target probable vent locations such as cracks, vegetation damage, etc.
While scanning the service line/meter where the location is known, keep these tips in mind:
•
Use the advantage of the beam by sweeping wider around the line location.
•
Work the beam up the line in an
“S”
pattern.
•
Scan the meter area.
•
Re-scan down the line using the
“S”
pattern.
•
Move in closer if the range is too far or ground elevation causes the beam to not come in
contact with the ground (dark zones).
While scanning a service where the location is not known:
•
Use an
“X” pattern
or similar pattern to thoroughly scan the area.
•
Target typical vent areas i.e., along the street or sidewalk edges.
•
Target locations where valves may be placed.
•
Scan along the foundation of the structure.
•
Move in closer if the range is too far or ground elevation causes the beam to not come in
Summary of Contents for HPN105354
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