WO1999054700A2

WO1999054700A2 - Infrared remote monitoring system for leak

Info

Publication number: WO1999054700A2
Application number: PCT/CA1999/000315
Authority: WO
Inventors: Horace Rekunyk
Original assignee: Horace Rekunyk
Priority date: 1998-04-20
Filing date: 1999-04-20
Publication date: 1999-10-28
Also published as: WO1999054700A3; AU3401499A

Abstract

Method and apparatus for determining the presence and identify of predetermined gases in the atmosphere such as would be found on a natural gas, natural gas liquid or oil pipeline if such pipeline was subject to leakage. An infrared transmitter and an infrared receiver are each mounted on a movable platform such as fixed or rotary wing aircraft or on a vehicle. As the moving platform follows its predetermined assigned route, the presence of gases is determined by the infrared transmitter and receiver and at least one data acquisition module. The geographic position of the movable platform is determined so that the geographic location of the predetermined gases in the atmosphere is known.

Description

INFRARED REMOTE MONITORING SYSTEM FORLEAK

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application serial number 08/770,365 filed November 29,

1996, now allowed.

INTRODUCTION

This invention relates to a method and apparatus for the measurement of hydrocarbon gases and hydrocarbon

related toxic gases and vapors in ambient air. More

particularly, this invention relates to a method and apparatus for the measurement of such gases by way of

infrared technology combined with an airborne or moving ground based platform.

BACKGROUND OF THE INVENTION

The use of infrared technology to determine the

presence or absence of hydrocarbons in ambient air is known.

Such methods position the technology adjacent the area of

interest and the receiver and transmitter are fixed in place at the location. Such location may, for example, be near a

pipeline which is carrying such gases or in a storage area where such gases are stored for processing or where they may

be transferred. The presence of such gases indicates

leakage and steps can then be taken to remedy the situation.

The use of an airborne or ground based moving

platform for mounting instrumentation is also known. Such

instrumentation may utilize a locator device to determine

the precise position of the platform relative to the ground

and the instrumentation will provide information which is

referenced to the known position. Typically, such instrumentation as cameras, thermal imaging and the like, have been used on airborne platforms .

Infrared technology has, however, not been used on

an airborne or ground based moving instrument platform for

pipeline surveillance and the use of such technology has

many advantages. Presently, visual identification to

identify pipeline leakage relies on an identification of

dead vegetation to identify leak sources and is limited to

the summer and areas with sufficient green vegetation during

those periods . In rared thermographic evaluations compare temperature differences between an oil or gas leak compared

to the environmental surroundings. The thermographic technique requires relatively lengthy time periods to

develop a thermographic image and does not work well in cold

climates or in areas with a significant vegetation canopy.

A flame ionization (FID) analyzer to evaluate ambient air

for hydrocarbon gases/vapors utilizes relatively small

samples . Thus , if the aircra or ground based vehicle is

moving quickly, the sample may not be representative and the

lag time until the same enters the FID analyzer is lengthy.

Likewise, the flame ionization instrument requires compressed hydrogen gas in order to operate . This presents a significant explosive and flammable hazard particularly

where the aircraft is flying fast and low and where the

ground based vehicle may be operated in urban areas .

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided apparatus to measure predetermined gases present between an infrared transmitter and an infrared receiver

mounted on a movable platform, means to measure the quantity

of predetermined gases present in the area between said

infrared transmitter and said infrared receiver and means to

correlate the measurement of said predetermined gases present between said infrared receiver and said infrared

transmitter and the geographic location of said movable

platform.

According to a further aspect of the invention, -

there is provided a method of measuring predetermined gases

present between an infrared transmitter and an infrared

receiver, said method comprising emitting infrared radiation

from said infrared transmitter, said infrared transmitter

being located on a movable platform, receiving a portion of said emitted radiation in said receiver from said

transmitter located remotely from said infrared transmitter,

determining the quantity of said predetermined gases present

between said infrared transmitter and said infrared

receiver, and correlating the measurement of said

predetermined gases by said receiver and transmitter to said

geographic position of said movable platform.

According to yet a further aspect of the

invention, there is provided a method to obtain information

concerning charge characteristics of a cathodic protection

device associated with a pipeline and having a transceiver

and circuitry associated therewith, said method comprising

being a vehicle into proximity and line of sight view with

said cathodic protection device, interrogating said

transceiver of said cathodic protection device from said

vehicle, receiving data transmitted from said transceiver of

said cathodic protection device and maintaining said

received data on said vehicle.

According to still yet a further aspect of the

invention, there is provided apparatus to interrogate a

cathodic protection device associated with a pipeline, said apparatus comprising a transceiver operably associated with said cathodic protection device and being operable to

transmit charge data associated with said pipeline, a power

source to supply electrical power to said transceiver and an

integrator to interrogate said transceiver and to receive data transmitted from said cathodic protection device.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Specific embodiments of the invention will now be

described, by way of example only, with the use of drawings

in which:

Figure 1 is a diagrammatic illustration of an open

path infrared detection system mounted on a movable airborne

platform according to the invention;

Figure 2 is a diagrammatic view of a flow through

infrared detection system according to a further aspect of

the invention;

Figure 3 is a diagrammatic view of the open path

configuration utilising a White cell technique within a tube of the instrument, the White cell technique being used to

increase the optical path of the infrared beam;

Figure 4 is a diagrammatic view of the open path

infrared detection system mounted on a ground based movable platform positioned on a vehicle;

Figure 5 is a diagrammatic view of an open path infrared detection system mounted on an movable airborne plat orm in a location different from the location

illustrated in Figure 1 and further utilising a single instrument body including a tube;

Figures 6A and 6B illustrate a methane "spike"

obtained from the simulated operation of the movable

airborne platform and the actual operation of the movable

ground based platform, respectively, the two "spikes"

representing an unusual condition at the geographical

locations noted;

Figure 7 illustrates the infrared detection system

mounted on a fixed wing aircraft; Figure 8 illustrates an enlarged view of the instrument of Figure 5 ;

Figure 9 is a diagrammatic aerial view of a

pipeline with a cathodic protection station located adjacent thereto according to a further aspect of the invention;

Figure 10 is an enlarged side view of the cathodic protection station on Figure 9;

Figure 11 is a diagrammatic view of an airborne vehicle used for transmitting and receiving data from the

cathodic protection station; and

Figure 12 is a view of a guidance array used to

direct the aircraft more closely to the cathodic protection

station.

DESCRIPTION OF SPECIFIC EMBODIMENT

The infrared sensor and locator system is

generally illustrated at 10 in Figure 1. It comprises an

infrared transmitter 11 and an infrared receiver 12 , each of

the receiver 12 and transmitter 11 being mounted on an airborne platform conveniently in the form of a helicopter 13. The transmitter 11 and receiver 12 could, for example, be mounted on the skids 16, 17 of the helicopter 13. The

transmitter 11 and receiver 12 are positioned below the body

of the helicopter 13 and are located a certain distance apart in an open path configuration. The spectrum which

results from the transmitted infrared radiation is gathered

in the infrared receiver 12 and passes to the data

acquisition system 15. The spectrum reflects the identity

of gases present between the transmitter 11 and receiver 12

and, if the gases present are known, the quantity of such

gases present may also be determined.

The helicopter 13 also has a global positioning

system ("GPS") 14 operably connected to the data acquisition

system. As information is obtained from the receiver 12,

the quantity of gases is correlated with the position of the

airborne plat orm 13. Thus , the position of any

contaminating emissions measured by the receiver 12 will be

quickly known and other units can be dispatched to that

location either to repair or to shut in the emission. The optical path of the infrared beam is illustrated in Figure 3. A "White cell" generally illustrated at 30 comprises a chopper wheel 31 which rotates to allow only a narrow beam 32 to pass therethrough as

illustrated. The beam 32 is reflected between mirrors 33, 34 so as to increase the length of the open path within which the ambient air is analyzed. By increasing the length of the open path, the sensitivity of the instrument increases since the detection limit is inversely proportional to path length. Thus, if the infrared beam 32 is reflected through the air sample, conveniently forty (40) times, an approximate forty (40) fold improvement in sensitivity is obtained. Other multiples are available as may be desired by the user.

The infrared (IR) light 32 generated by an IR source (not illustrated) enters the White cell 30. The IR

light passes between the field mirror 34 and objective mirrors 33 many times, conveniently in the case of methane, forty (40) times. The White cell 30 is open to the sample air, which may or may not contain methane or other analyte gases. The IR light 32 exits the White cell 30 and passes

through a four segment optical chopping wheel 31. Two segments of the wheel are opaque to all infrared radiation,

one segment being an IR transparent cell containing methane

and the fourth segment being an IR transparent cell

containing nitrogen. After passing through the optical

chopping wheel 31, the IR light 32 is split into two beams

by an IR beam splitter 42. One of the beams passes through

a 3.31 micrometer optical bandpass filter and the intensity of the transmitted beam is measured by detector 44. The second beam passes through a 3.89 micrometer optical

bandpass filter and the intensity of the transmitted beam is

measured by detector 43.

The methane concentration is proportional to the

ratio of the intensity measured by detector 44 when the

nitrogen segment of optical chopper 31 is in the light beam.

The concentration of total hydrocarbon is proportional to the intensity of light measured by detector 44 to the

intensity of light measured by detector 43, both taken when the nitrogen segment of optical chopper 31 is in the light

beam.

An alternative or "flow through" infrared detection systems is illustrated in Figure 2. In this embodiment, the helicopter or airborne platform 20 includes

a probe 21 which extends from the forward end of the

helicopter 20. The probe 21 is typically of stainless steel

and has an inside diameter of approximately 1/2 inch. The gas (not illustrated) enters the open end of the probe 21

and passes to a flow through infrared analyzer 22 through

inlet 23. A data acquisition system 24 is operably connected to the infrared analyzer 22 and a GPS 25 is

operably connected to the data acquisition system 24 so, as described earlier in connection with the open path infrared

detection technique, the geographic location of the airborne

platform 20 together with the aircraft speed, time of day and altitude will be known according to the data obtained by

the data acquisition system 24 in the analyzer 22.

OPERATION

In operation, the helicopter 13 will be flown near

an area where potential leakage of hydrocarbon gases may

occur. The airborne platform, be it the helicopter 13 or a

fixed wing aircraft 70 (Figure 7) will typically be operated

at a speed of 50 to 100 miles per hour and at an altitude of

50 to 100 feet. Such an area of operation would typically encompass an oil or natural gas or natural gas liquid

pipeline and such gases would typically be hydrocarbon

emissions due to leakage in the aforementioned pipelines .

The operation of the infrared transmitter 11 and

infrared receiver 12 is initiated together with the data

acquisition system and the global positioning system ("GPS") 15.

As the helicopter 13 proceeds down its assigned flying corridor, gases will be present in the atmosphere and

the infrared detection system 10 will be programmed so as

only to respond to those gases which it is desired to detect

as has been described. When such gases are detected, the

quantity of such gases will be determined and this amount

will then be stored in the data acquisition system 15 and

correlated with the geographic position of the instrument

platform of the helicopter 13 as determined by the GPS 14'.

When the helicopter 13 has reached the end of its

route and has returned to its operating base, the

information on the data acquisition system 15 will be

downloaded and reviewed for any predetermined gases present, such as methane, and their amount. If such gases are

detected and the quantity of such gases are of concern,

remedial action can be taken to determine the source of the gas and how to reduce or terminate its presence.

For example, and with reference to Figures 6A and

6B, spikes 50, 71 have been detected which clearly stand out

from the usual concentration of methane in the atmosphere as shown generally at 54, 72, respectively, as degrees of

longitude are traversed by the helicopter 13 as shown on the abscissa of the plot. The latitude and longitude of the

location of the spike 50 is recorded by the GPS and illustrated at 56. The location of the spike 72 in Figure

6B is shown at 73. The weather conditions under which the

aircraft 13 was operating are also provided at 55 in Figure

6A. Thus, remedial and service units can be deployed to the

proper position to determine the cause of the spikes 50, 72.

Figure 6A was obtained in a simulated test using an open

valve with an airborne helicopter using the infrared

detection system. Figure 6B was an actual occurrence and

was obtained using a movable platform on a ground based vehicle . The "open path" analyzer 10 of Figures 1 and 5 can constantly analyze a large representative sample of the gases present in the atmosphere. A sample rate of

approximately 3000 liters/second is contemplated. The "flow

through" analyzer illustrated in Figure 2 is a lower rate

sampler, typically about 500 to 1000 cubic centimeters/ in.

Many modifications will readily occur to those skilled in the art to which the invention relates . For

example, rather than an airborne platform on a helicopter

13, the airborne platform 80 could be mounted on the fixed

wing aircraft 72 (Figure 7) with the instrument 81 attached

thereto . Likewise, although the primary area of application

will be in the evaluation of hydrocarbon gases/vapors, the

technology is also applicable to detect other such gases as

carbon dioxide, carbon monoxide, sulfur dioxide, ammonia or

other analyte gases as the user may desire.

A further embodiment of the invention is

illustrated in Figure 4 in which a ground based moving

platform, namely a truck or vehicle generally illustrated at

51, has the infrared detection system generally illustrated

at 52 mounted on the forward end of the vehicle 51. The GPS acquisition system 53 is located in the interior of the

vehicle 51. The use of the GPS acquisition system 53 on the vehicle 51 is most useful only in rural and sparsely settled areas which, of course, is where many miles of pipelines and other surface facilities are located. However, if the area

of interest is located in an urban area, the GPS system 53 suffers from accuracy problems due to the difficulty in

obtaining line of sight between the plurality of satellites providing triangulated input parameters to the GPS system

because of the presence of buildings, trees, tension lines

and the like. For this reason, it may be desirable to use a

dead reckoning technique under these conditions . The dead

reckoning technique may typically use city maps , compass

means , speedometer means and/or a measuring wheel and the

like .

Yet a further embodiment of the invention is

illustrated in Figure 5. An airborne platform, conveniently

a helicopter 60 , will have an infrared detection system 61

mounted on platform 62 similar to the embodiment of Figure

1. However, whereas the receiver 12 and transmitter 11 of

the infrared detection system 10 of Figure 1 were mounted on

opposite skids 16, 17 of the helicopter 13 and do not utilise a self-contained instrument with a tube 84 (Figure 8) , in the Figure 5 embodiment the receiver (not

illustrated) and transmitter (not illustrated) are both

mounted on the same platform 62 in a single instrument 61

attached to skid 63. The skids 63, 64 of Figure 5 and the

skids 16, 17 of the helicopter 13 in Figure 1 are typically hydraulically mounted so as to more sof ly impact the ground

when landing. During that period, there is relative

movement between the transmitter 16 and receiver 12 of the Figure 1 embodiment since they were mounted on different

skids 16, 17. By mounting both the receiver and transmitter of the infrared detection system 61 on the same skid 63 as

shown in the Figure 5 embodiment, such relative movement is

removed which allows greater integrity in calibrating and

setting the instrument up for operation.

Whereas the analysis of the data obtained by the

data acquisition system has been previously described as

being downloaded for processing and analysis , it would be

desirable to transmit the data obtained directly to a processor located remotely from the data acquisition segment

for real time processing and review by a remotely located

operator . This would be desirable under certain conditions where analysis was required as early as possible .

Alternatively, an operator on the aircraft or vehicle could

identify anomalies concurrent with its acquisition.

While the White cell technique previously

described covers principally methane, the measurement

technique can be extended to other gases by changing the

wavelengths of the optical bandpass filters in front of

detectors 43, 44 (Figure 3) and. by changing the gases in the

IR transparent segments of the optical chopping wheel 31.

A further aspect of the invention relates to

obtaining charge readings from cathodic protection device .

Cathodic protection devices provide a charge to various

metallic structures which are operably positioned within the

ground. Such structures include pipelines, cathodic

protection anodes , re erence cells , recti iers or other

power sources , casings , storage tanks and the like . The use

of cathodic protection increases the life of such

components , the requirements generally being dictated

according to the local soil conditions where such metallic

structures are located and it is necessary, from time to

time , to monitor the charge readings to ensure that the charge is being properly transferred to the metallic structure so as to prevent deterioration of the structure and that the charge is appropriate for the soil conditions which may change from time to time .

Heretofore, the readings of such cathodic test

stations were generally obtained by one or a combination of

three techniques . In a first technique , the readings were

obtained manually by a team or individual who travelled to the site of the cathodic test station by foot, ATV vehicle or otherwise. The readings from the terminal board mounted

on the cathodic test station were taken with instrumentation carried by the operator and then analyzed. The difficulties

associated with the technique included the fact that many

test stations are located in remote locations where travel

is only possible during certain seasons. Likewise, the cost

and time associated with the manual instrumentation reading

technique are substantial.

A second technique for taking the readings is by

way of a cellular phone or other wireless radio technique. This method interrogates the test station and the data is

subsequently transmitted to the nearest antenna operably associated with the cellular phone or wireless radio and

test station. The antenna may be located some distance from

the test station and the power requirements for the transmission of data from the test station are significant.

If the power is supplied from a battery, the battery must be

periodically recharged which may well be inconvenient and,

in any event, is costly. Otherwise, a reliable local power

supply is necessary which may not be available in such a

remote location. For practical . purposes , therefore, the

technique is restricted to rectifier facilities or local

plants where such power facilities are available.

A further or third technique utilizes low earth

orbit satellite networks or AMSC . The test stations are

interrogated when the satellite is overhead and the charge

data is subsequently transmitted to the satellite. Again,

the power required for such transmission from the test

stations limits the use of such techniques to plant and rectifier facilities where reliable local power is

available. Further, sophisticated and expensive hardware is

required for the satellite interrogation and transmission

technique . The further embodiment of the invention is illustrated in Figures 9, 10, 11 and 12 which relate to the interrogation of cathodic test station locations . In this

embodiment, a cathodic protection monitoring station is generally illustrated at 100. It takes the form of a

cylinder and is located besides and above pipeline 101. It

is buried within the ground 105 adjacent to the pipeline 101

to a distance of approximately one-half its length as seen

in figure 10. Cathodic protection station 100 is wired to receive charge and electrical data from the pipeline 101 or

other metallic structure so that the condition of the charge

flowing from or to the pipeline 101 may be obtained from

appropriate terminals located beneath a plastic cap 110 on

the test station 100 which is used to protect the terminals

and the associated components and circuitry from adverse

weather operating conditions and so that other cathodic

protection data can be obtained and accessed.

The cathodic protection requirements for pipelines

are generally defined by the companies operating the

pipeline, which regulations or operating requirements are

dictated by the particular soil or other conditions to which

the pipeline 101 is subjected. These requirements include the application of cathodic protection to effective reduce

corrosion of the pipeline or other metallic structure. This

information is important and must be monitored regularly.

A TAG or smart card 111 is mounted at the cathodic

protection station 100 and receives and stores electrical

data from pipeline 101. The smart card 111 also holds data indicating the identity and geographic location of the cathodic protection station 100, the location of the

catnodic protection station 100 being compared with the

location as given on a GPS locator device as will be

described.

A low power transceiver 112 is located at the

cathodic protection station 100 and may be integrated with

the smart cad 111. The low power transceiver 112 is

conveniently powered by a longlife battery, such as a

lithium battery 113 which is intended to provide power fox

transmitting data for a very short distance, approximately 200 feet or so. By operating in this manner, the lithium

battery 113 has a relatively long life and need only be

replaced at fairly long intervals. An airborne vehicle, conveniently a helicopter 114 contains an integrator 115, an antennae 116, a GPS locator

device 117 and associated circuitry which will interrogate

the transceiver 112 and/or smart card 111 at the cathodic

protection station 100 and receive the data transmitted from

the transceiver 112 when it is interrogated. The integrator

115 will store the received data and download it for

analysis when convenient to do so or, alternatively, it may be shown real time in the helicopter 114 so that any

servicing can be performed at the same time the vehicle 114

is adjacent the station 100.

A guidance array 120 is located within the

aircraft 114 (Figure 9) . The guidance array 120 provides a

plurality of light emitting diodes 121 located generally

transverse to the line of sight of the pilot of the aircraft

114. As the aircraf 114 approaches the location of the

cathodic protection station 100, the integrator 115 will

interrogate the cathodic protection station 100 as to its

location. A beacon or other homing device at the cathodic

protection station 100 will provide the necessary guidance

to the array 120 and will act similarly to an aircraft

transponder to provide data to the LED' s 121 thereby indicating the proper position of the cathodic protection station 100 relative to the aircraft 114. This will allow

more accurate navigation by the pilot and reduce power

requirements for data transmission. It is intended that the

data received from the cathodic protection station 100 be

transmitted to aircraft 114 when the aircraft 114 is within

500 feet of the station 100 and, preferably, within 200 feet of the station 100.

In operation, the pilot of the aircraft 114 will fly the route of the pipeline 101. He will periodically

interrogate the various cathodic protection stations 100

located intermittently along the pipeline route using

integrator 115 and direct the aircraft 114 to a location

close to each cathodic protection station 100 by using

guidance array 120. When each location is reached, the

transceiver 112 of the cathodic protection station 100

transmits data to the integrator 115 which data has been

received and stored on the TAG or smart card 111 at the

cathodic protection station 100. The data transmitted from

the smart card 111 conveniently includes the location of the

particular cathodic protection station 100 being

interrogated such that it may be compared with the location of the aircraft 114 by way of a GPS device 117 located in aircraf 114. Likewise , the transmission of data from the

cathodic protection station will be tested for integrity

during initial data transmission to ensure that all transmitting and receiving components on the station 100 are

operating properly. Then the charge characteristics

pertaining to pipeline 100 will then be obtained. Thus,

when the data is received by integrator 115, the location of

the particular cathodic protection station 100 and the charge characteristics associated with the pipeline 100 for

the location of each individual cathodic protection station 100 can be reviewed for determination of any remedial action

necessary. The received data may be stored for downloading

or reviewed in real time mode on the aircraft 114.

While an aircraft 114 has been described as being

useful to obtain the charge information from the cathodic

protection station 100, other vehicles may also be

conveniently used such as a ground based vehicle like a car

or a truck. It is important, however, that the vehicle

used, be it airborne or ground based, be brought relatively

closely to the cathodic protection station 100 in order to

allow the transceiver 112 on the station 100 to transmit the stored data to the vehicle using a minimum amount of power from the batteries used. This will allow the life of the

batteries to be extended in order to avoid the use of local

based power supplied which may not be available in any event.

Many other modifications will readily occur to

those skilled in the art to which the invention relates and

the specific embodiments described should be taken as s illustrative of the invention only and not as limiting its scope as defined in accordance with the accompanying claims.

Claims

WHAT IS CLAIMED IS:

1. Apparatus for detecting gases by emitting infrared radiation from a transmitter to pass through said gases and to be received by a receiver, said transmitter and said receiver being located on a movable platform, the improvement comprising passing said gases of predetermined identity through the signal passing between said transmitter (11) and said receiver (12) , said transmitter (11) and said receiver (12) being positioned within an instrument (10) located on a movable platform (13, 51) , the distance between said receiver (12) and said transmitter (11) defining a signal path (30) for a signal (32) emitted by said transmitter (11) within said instrument (10) , said signal path (30) being of predetermined length (30) and said gases being detected by said signal (32) within said signal path (30) on said movable platform, means (10) to measure the quantity of said predetermined gases passing through said signal (32) within said instrument (10) and means (25) to correlate the measurement of said predetermined gases present within said instrument (10) between said infrared transmitter (11) and said infrared receiver (12) and the geographic location of said movable platform (13, 51) .

2. Apparatus as in claim 1 wherein said movable platform is an airborne platform (13) .

3. Apparatus as in claim 1 wherein said movable platform is a ground based platform (51) .

4. Apparatus as in claim 1 wherein said geographic location of said movable platform (13, 51) is determined by a global positioning system (25) .

5. Apparatus as in claim 1 wherein said geographic location of said movable platform is determined by dead reckoning.

6. Apparatus as in claim 2 wherein said airborne platform is a helicopter (13) .

7. Apparatus as in claim 2 wherein said airborne platform is a fixed wing aircraft (70) .

8. Apparatus as in claim 1 wherein said predetermined gases are hydrocarbon gases or vapors .

9. Apparatus as in claim 8 wherein said hydrocarbon gases or vapours are methane gases .

10. Apparatus as in claim 1 wherein said predetermined gases include carbon dioxide, carbon monoxide, sulfur dioxide, ammonia and other analyte gases .

11. Apparatus as in claim 1 wherein said transmitter (11) and said receiver (12) are positioned in an open path configuration (30) .

12. Method for measuring predetermined gases by emitting infrared radiation from a transmitter to pass through said gases and be received by a receiver, said transmitter and said receiver being located on a movable platform, the improvement comprising positioning said transmitter (11) and said receiver (12) within an instrument (10) located on said movable platform (13, 51) , said infrared radiation being emitted from said transmitter (11) and received by said receiver (12) defining a signal path (30) having a predetermined and fixed length and being within said instrument (10) , passing said instrument (10) through said predetermined gases and determining the presence of said gases between said transmitter (11) and said receiver (12) within said length of said signal path (30) and correlating the measurement of said predetermined gases by said receiver (12) and said transmitter (12; to the geographic position of said movable platform (13, 51) .

13. Method as in claim 12 wherein said receiver

(12) and said transmitter (11) are positioned in an open path configuration (30) within said instrument (10) .

14. Method as in claim 13 wherein said predetermined gases are hydrocarbon gases.

15. Method as in claim 13 wherein said hydrocarbon gases are methane gases .

16. Method as in claim 13 wherein said predetermined gases include carbon dioxide, carbon monoxide and sulfur dioxide , ammonia and other analyte gases .

17. Method as in claim 13 wherein said quantity of said predetermined gases present is obtained by an acquisition module (24) .

18. Method as in claim 12 wherein said geographic location of said instrument is obtained by a global positioning system (25) .

19. Method as in claim 12 wherein said geographic location of said instrument (10) is obtained by dead reckoning.

20. Apparatus as in claim 1 wherein said movable platform (13, 51) is mounted on a ground based vehicle (51) .

21. Apparatus as in claim 11 wherein said open path configuration utilises a white cell (30) .

22. Method as in claim 13 wherein said open path configuration is a white cell configuration (30) .

23. Method to obtain in ormation concerning electrical data from a cathodic protection device associated with a pipeline or other metallic structure and having a transceiver and circuitry associated therewith, said method comprising being a vehicle into proximity and line of sight view with said cathodic protection device, interrogating said transceiver of said cathodic protection device from said vehicle, receiving data transmitted from said transceiver of said cathodic protection device and maintaining said received data on said vehicle.

24. Method as claimed in claim 23 wherein said vehicle is an aircraft.

25. Method as claimed claim 23 wherein said vehicle is a ground based vehicle.

26. Method as in claim 23 wherein said cathodic protection device has a transceiver and a storage medium associated with said cathodic protection device.

27. Method as in claim 26 wherein said storage medium and transceiver associated with said cathodic protection device are electrically powered.

28. Method as in claim 27 wherein said electrical power is provided by a battery.

29. Method as in claim 28 wherein said battery is a lithium type battery.

30. Apparatus to interrogate a cathodic protection device associated with a pipeline, said apparatus comprising a transceiver operably associated with said cathodic protection device and being operable to transmit charge data associated with said pipeline, a power source to supply electrical power to said transceiver and an integrator to interrogate said transceiver and to receive data transmitted from said cathodic protection device.

31. Apparatus as in claim 30 wherein said source of electrical power is a battery.

32. Apparatus as in claim 31 wherein said battery is a lithium powered battery.

33. Apparatus as in claim 32 wherein said integrator interrogates said cathodic protection device from a distance relative closely to said cathodic protection device.

34. Apparatus as in claim 33 wherein said distance is 200 feet or less.

35. Apparatus as in claim 34 and further comprising an aircraft, said integrator being positioned on said aircraft.