Heath Consultants RMLD-FR, Руководство оператора

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Operator’s Manual
21
RMLD-FR
Doc No. 16086 Rev A, RMLD-FR Operator Manual © 2021 Heath Consultants Incorporated. All rights reserved.
1
Laser Beam
Is Transmitt
ed
2
Plume Absorbs
Some Laser
3
Some Laser
Passes Through
6
Remaining Laser R
eturns t
o
RMLD-FR and Is Measur
ed
4
Laser
Reflects Back
5
Plume Absorbs
Some Laser
How Does the RMLD-FR Measure Gas?
The RMLD-FR uses infrared
(IR) laser technology known
as Tunable Diode Laser
Absorption Spectroscopy
(TDLAS).
TDLAS enables the Operator to
safely scan:
- Hard to reach areas
- Plumes up to 100’ away
(actual distance may vary
due to surface condition)
- Through windows
When the laser passes through a
gas plume, a portion of the light is
absorbed by methane, while some
of the light is reflected back to the
RMLD-FR. The reflected light is
collected and processed so the
RMLD-FR can report methane
concentrations in parts-per-million-
meter or PPM-M.
Infrared beam width is about 22” at 100 feet. It is important to note that the laser
beam “footprint” width increases as the distance increases. This is why it is much
easier to detect natural gas from a distance of 10 to 15 feet and beyond.
NOTICE: There is always a small
amount of methane in the air.
This natural methane background
is also measured by the RMLD-FR.
The PPM-M reading will then
increase as the scanning distance
increases.
NOTICE: The nature of a gas plume
is highly variable. The above/right
illustrations are intended to convey
the basic theory. Some leaks may
have a high surface concentration
with little to no measurable plume
above the surface.
NOTICE
0.5 M
1000 PPM
2 M
1000 PPM X 0
.5 M = 500 PPM-M
20 PPM X 2 M = 40 PPM-M
+ background le
vel of 15 PPM-M = 55 PPM-M
20 PPM
A
B
a) Gas cloud of 1000 PPM is about ½ meter in width (the distance the
infrared beam passes through the plume). RMLD-FR measures 500 PPM-M.
b) Average concentration of gas cloud is 20 PPM and is about
two (2) meter in width. RMLD-FR measures 40 PPM-M,
plus 15 PPM-M background level, displaying a total value of 55 PPM-M.
A
B
100’ 50’ 25’ 75’
22”
WARNING - The RMLD-FR is
capable of scanning through
windows to possibly detect meth-
ane gas. However, scanning through
windows is not guaranteed. False
positives and negatives may occur.
WARNING