Remote Methane Leak Detector

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Remote Methane Leak Detector
Southern Gas Association Distribution Operations
Maintenance Wednesday, July 19 2006
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RMLD Key Requirements

• Remotely detect methane up to 100 away
• Portable, lightweight and rugged
• As effective as existing leak survey tools
  methods
• Specific to detect methane gas only
• Not intended to be a leak pinpointing or
  measurement tool (CGI)

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RMLD Concept
Do not need to be in gas plume!
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Based on TDLAS Technology

• Tunable Diode Laser Absorption Spectroscopy
  (TDLAS)
• Every gas absorbs specific wavelengths,
  (frequencies) of light
• The RMLD laser beam emits a wavelength which is
  absorbed by methane
• The amount of laser light absorbed is
  proportional to the total amount of gas in the
  path of the laser beam
• Concentration is then expressed as
  parts-per-million-metered, or ppm-m

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Technical Approach

• Laser light beam is remotely projected on to a
  target (e.g., grass, wall, etc.)
• A fraction of the beam is scattered from the
  target surface and returned to the source
• Returned light is collected and focused onto a
  detector
• The presence of methane is encoded within the
  returned light
• Methane readings are displayed in ppm-m

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Benefits RMLD has re-invented walking surveys!

• Perform most surveys without physically walking
  service lines
• Survey hard to reach areas
• Backyard mains
• Over or through fences
• Pipelines in bridges/overpasses
• Wider area of search due to sweeping of the beam
• Productivity savings 20 to 40 for most
  utilities
• Able to remotely check inside buildings or
  confined spaces for presence of methane
• Rapid warm-up
• Built in self test and calibration

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RMLD Production Design
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RMLD Production Instrument
SPOTTER
MEASURING LASER SOURCE
SPOTTER LASER TRIGGER
Control Unit and Harness
Transceiver
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General Specifications

• Weight 9lbs (Controller 6lbs and Transceiver
  3lbs)
• Rugged, splash-proof and weather resistant
• Detection range 2 feet to 100 feet
• Modes of Operation DMD and Pure Tone
• Sensitive to 5 ppm-m
• Built in self test and calibration
• IR laser Class I
• Spotter laser Class IIIa
• Rechargeable battery lasting over 8 hrs
• User friendly interface with audible tones
• Operating temperature from 0F to 120ºF
• Ergonomic design with shoulder harness

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Laser Safety

• Infra-red Detector Laser
• Class I
• Always on when instrument is on. This laser is
  invisible.
• Green Spotter Laser
• Class IIIa
• Under the control of the operator
• Same rating as pointer lasers commonly sold in
  stores and used for business presentations
• Safe when handled properly

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RMLD Operates Differently Than Flame Ionization

• Remotely detects gas everywhere within the laser
  path length
• Measures PPM-Meter not PPM
• PPM-Meter reading is sum of concentration x plume
  width
• Use of scanning techniques to detect and localize
  leaks

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PPM-Meter vs. PPM
Example 1
1m
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Field Operations
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Field Operations
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Video