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The OMD operates reliably under a variety of environmental
conditions including dry weather, snow, ice and temperatures
from -22° F to +122° F.  Its sensitivity, calibration or response |is
not affected by small fluctuations in the light beam or by reasonable
amounts of dust, or snow on the optics.  An internal calibration test
cell is included so the operator can verify proper operation from the
vehicle cab at any time before, during or after a leak survey.  An
Installation Mounting Kit is available for mounting the OMD to the
front of a vehicle.  All interconnecting cabling is provided with the
OMD including the cable to obtain power to operate the instrument
from the survey vehicle 12 volt battery.  An RS232 port is included
whereby a personal computer may be connected to acquire and
save the survey data with the appropriate software.

Depending on local meteorological conditions, a given amount
of gas escaping from the ground will produce a plume that
varies in size and uniformity of concentration levels.  The
plume, of its very nature, defies quantification by fixed or
moving detectors.  Regardless of these uncertainties, it is of
paramount importance to be able to detect gas when gas is
present.  Concentration levels of the measured gas are of
interest, but are of secondary importance.  Consequently, the
ability of a detector to detect the plume with accuracy and
precision is not as important as its ability to do so with good
sensitivity (or a low detection limit) and with a minimum of
false alarms.

There are two kinds of false alarms: false negatives and false
positives.  False negatives occur when a leak is missed.  The
detector is saying there is no gas present when, in fact, a leak
was present but undetected.  False positives occur when the
detector says that a gas leak is present when it really is not.
Examples of false positives experienced include the detection of

O

VERVIEW

Содержание OMD

Страница 1: ... USER S OMD USER S OMD USER S OMD USER S Manual Heath Consultants Incorporated Houston TX 713 844 1300 Fax 713 844 1309 1 800 HEATH US www heathus com Heath Leadership Innovation Performance Then Now and Tomorrow RevD ...

Страница 2: ...2 ...

Страница 3: ...Installation 14 Display Connectors 15 Vehicle Grounding Strap 15 Protective Cage 16 CHAPTER III OPERATING PROCEDURE 18 Start Up 18 Display Function 20 HOLD 20 LIGHT 21 SAMPLE 22 PPM Range 23 Alarm Set Point 25 Error Messages 26 Shut Down 27 CHAPTER IV ALIGNMENT PROCEDURE 28 Lamp Alignment 29 Receiver Alignment 30 CHAPTER V CALIBRATION CHECK 31 Verifying Calibration With Internal Cell 31 Verifying ...

Страница 4: ...ecommended Spare Parts 34 Troubleshooting 34 CHAPTER VII SERVICE INFORMATION 37 Warranty and Warranty Repairs 37 Customer Assistance and Service Locations 38 Appendix A SURVEY PROCEDURES MOBILE OMD 40 Appendix B DRAWINGS 55 USING ADOBE ACROBAT READER 60 ...

Страница 5: ...Line Compensation Via RS 232 through software Display Back lit 2 x 6 graphics LCD adjustable contrast Operator Interface Sealed membrane switch overlay Operator Alarms Signal High pitch audible with adjustable set point pitch increases with concentration Adjustable volume Error Low pitch audible with adjustable set point Error alarms provided for Warm up LowLight CommunicationFailure Batterylow Sy...

Страница 6: ... 32 51 25in 2in MechanicalMounting Strut bracket mount Installation Time 2 hours typical External Housing Rating NEMA 3S and IP 54 Display Housing Rating Spill proof External Sub System Materials Aluminum and plastic Environmental PCB Control Conformal PCB coating Operating Temperature Range 22 F to 122 F Operating Humidity Range 5 to 100 RH non condensing ...

Страница 7: ...rt across the width of the vehicle An optical filter in front of the detector transmits primarily methane specific IR wavelengths from the light source In the absence of methane these wave lengths are unaffected and produce a steady output signal from the detector When the vehicle passes through a plume of natural gas methane in the plume will absorb some of the IR light reaching the detector As a...

Страница 8: ...meteorological conditions a given amount of gas escaping from the ground will produce a plume that varies in size and uniformity of concentration levels The plume of its very nature defies quantification by fixed or moving detectors Regardless of these uncertainties it is of paramount importance to be able to detect gas when gas is present Concentration levels of the measured gas are of interest b...

Страница 9: ...r for the OMD operation Please refer to the GPTC Guide for Transmission and Distribution Piping Systems 1998 2000 Guide Material Appendix G 192 11 Section 4 Leak Detection 4 4 Leakage surveys and test methods a Surface Gas Detection Survey Part 3 Utiliza tion The use of this survey method may be limited by ad verse conditions such as excessive wind excessive soil moisture or frost or surface seali...

Страница 10: ...do not bend the support rod The u bolts should be tight enough to hold the OMD crossbar securely in place but not so tight as to distort the crossbar If that happens re alignment may be required We recommend using only two insulated u bolts to mount the OMD crossbar to minimize the possibility of distorting the crossbar The follow ing procedure will generally work best For your convenience we have...

Страница 11: ...d sliding the OMD up or down to the desired position In addition the shelf brackets can be mounted facing upward so that the OMD can be extended another 10 up toward the hood The shelf brackets can also be mounted downward so that the OMD can be extended another 10 down toward the ground Additional Notes On Crossbar Installation One of the most important points to consider when installing the cros...

Страница 12: ...oning was to eliminate the need for routing multiple cables into the vehicle cab However field experience indicates that in some instances heat from the vehicle engine coupled with high ambient temperatures can result in Power Box failures The current suggestion is to mount the Power Box inside the cab of the vehicle The first thing to consider when mounting the power box inside the cab is cable l...

Страница 13: ...the firewall or through the floorboard If you mounted the power box inside the cab you will need to route the other three cables into the cab as well INSTALLATION Unless a hole large enough to route the cabling through already exists you will need to drill one A hole approximately 1 1 8 inches in diameter should be sufficient to route one or three cables A 1 1 8 inch rubber grommet should be used ...

Страница 14: ...onnecting power polarity must be observed If the positive and negative leads are reversed thefusewillblowimmediately Theredwireshouldbe connected to the positive terminal and the black wire connected to thenegativeterminalofthebattery Note Connect the battery cable up last Be sure that the receiver cable is connected prior to making the battery connection Damage to the electronics may occur if not...

Страница 15: ...tions need to be observed Ground strap must be mounted to the vehicle chassis Avoid mounting to any surface that is painted or plated Ground strap should have a minimum of three inches of the strap in contact with the surface being traveled over INSTALLATION Display Connectors There are three connectors on the side of the display box The first is for the system cable which comes from the power box...

Страница 16: ... vehicle it is in danger of being damaged due to the possibility of bumping into something We recom mend that a cage be built around the OMD to protect it It would be nearly impossible to build one cage that would fit on every type of vehicle used for mobile surveying Therefore Heath does not offer one at this time We recommend that you take your vehicle to a local fabrication shop to custom build...

Страница 17: ...17 Photos of Protective Cages INSTALLATION ...

Страница 18: ...he LIGHT SOURCE button The red LED above the LIGHTSOURCEbuttonwilllightupandnormaloperationof thesystemwillbegin Ifthevehiclewillbeturnedofffora break turn off the LIGHT SOURCE to save the automobile battery while keeping the System Power on A message prompting the operator to turn on the LIGHT SOURCE to resume operation will be displayed System current con sumption with the light is approximately...

Страница 19: ...nal level from 2 to 17 PPM will be expected when the CALIBRATION TEST button is pressed Some deviation from this exact number is acceptable as indicated by the range on the data sheet It is good practice to occasionally press the CALIBRATION TEST button during the daily operation of the system to insure that the system is operatingproperly The concentration of the gas within this test cell is actu...

Страница 20: ...hree modes HOLD LIGHT SAMPLE These modes are entered by consecutively pressing the DISPLAY FUNCTION button to scroll through each Begin ning with HOLD as you continue to press the button the mode changes from HOLD to LIGHT to SAMPLE and back to HOLD again as indicated by the direction of the arrow HOLD This is the power up default position indicated by the line under the word HOLD This position wi...

Страница 21: ...w a low limit the LOW LIGHT alarm will be activated at the level indicated by the data sheet that was shipped with your instrument At that point it may be necessary to clean the lenses the HOLD mode The following picture shows the OMD in the HOLD mode PRESENT 0 0 MAXIMUM 16 6 SETPOINT 30 0 10 PPM 0 PPM Push Display to Continue Push Display to Continue Push Display to Continue Push Display to Conti...

Страница 22: ... display will show a one minute time history of the methane level The right most point displayed is the most recent and the display scrolls to the left If no errors are present the left side of the display will show the PRESENT methane level at the top left corner of the LCD This is the peak PPM level sensed in the last 1 2 second At the left center of the LCD the MAXIMUM methane PPM level is show...

Страница 23: ...dicate the gas concentrations over 200 PPM independent of the setting of the PPM RANGE button The PPM RANGE button only changes the amplification of the one minute history on the right hand side of the LCD The 90 range is the power up default position indicated by the line under the number 90 Press the button to change the range from 90 to 30 to 10 and back to 90 again as indicated by the directio...

Страница 24: ...EDURES PRESENT 0 0 MAXIMUM 16 6 SETPOINT 30 0 30 PPM 0 PPM Here is a 16 6 PPM leak displayed in the 30 PPM range PRESENT 0 0 MAXIMUM 16 6 SETPOINT 30 0 10 PPM 0 PPM Here is a 16 6 PPM leak displayed in the 10 PPM range ...

Страница 25: ...ructions The ALARM SETPOINT is adjustable from 10 to 40 PPM in 2 PPM increments with the value preset to 30 PPM when the system isfirstturnedon CAUTION IT IS NOT RECOMMENDED THAT YOU ALLOW THE ALARM TO BEEP CONTINUOUSLY FOR AN EXTENDED PERIOD OF TIME THIS COULD CAUSE PREMATURE FAILURE OF THE ALARM BUZZER THIS IS COMMON WHEN YOU GET OUT OF THE VEHICLE TO VERIFY A LEAK YOUR VEHICLE COULD BE PARKED C...

Страница 26: ...suffi cient due to an obstruction of the light path i e dirt or another obstruction or when the light bulb fails If the LIGHT error occurs press the DISPLAY FUNCTION button to place the instrument in the LIGHT mode and observe the numbers When this number drops below the alarm set point typically 200 the LIGHT alarm will occur The optics may be cleaned if neces sary toimprovethelightintensity Ifcl...

Страница 27: ...SE TO FUNC TION PROPERLY AND IN SOME CASES PERMA NENT DAMAGE MAY RESULT IT IS RECOM MENDED THAT THE INSTRUMENT NOT BE SUB JECT TO EXTREME CONDITIONS SUCH AS A CLOSED VEHICLE IN DIRECT SUNLIGHT OR CONTINUOUS SUBFREEZING TEMPERATURES SHUT DOWN At the end of the workday press the SYSTEM POWER button to turn off all power A typical standby current of 50 Miliamps is required when the OMD is OFF This is...

Страница 28: ...s procedure There are no adjustments to be made inside the Receiver or the Light Source The design relies on the mechanical tolerances to place the components in the proper place Final alignment makes use of the external alignment screws on the Light Source and the Receiver Tobealigned firstcleanthelightsourceandreceiverinputlenses Turn on the system power and press Display Function on the display...

Страница 29: ...mponents of the Receiver to the Detector Place a piece of tracing paper in front of the receiver input lens and you will be able to see the rectangular shaped light beam projected onto the lens as well as the outline of the lens itself If this light beam is not projecting onto the receiver lens at its cen ter adjust the alignment screws on the back of the light source until it is ...

Страница 30: ...gative number This last step directs the optical beam through the optical components of the Receiver to the Detector Be sure to tighten all nuts on lamp and receiver after alignment LIGHT LIGHT LIGHT LIGHT LIGHT LEVEL LEVEL LEVEL LEVEL LEVEL 746 2 746 2 746 2 746 2 746 2 756 5 756 5 756 5 756 5 756 5 767 1 767 1 767 1 767 1 767 1 777 4 777 4 777 4 777 4 777 4 786 8 786 8 786 8 786 8 786 8 Push Pus...

Страница 31: ...ed techni cian The calibration of the OMD must be verified at the beginning of each workday to insure the instrument is func tioning properly Verifying Calibration with Internal Check Cell Before verifying functionality of your OMD the optical path should be clean and aligned properly and the system should be thoroughly warmed up approx one hour The internal check cell should be used on a daily ba...

Страница 32: ...andard crossbar Therefore the display will read 100 times lower than the actual gas in this cell Place this cell in the center of the light path and observe the PPM reading on the display The display should read the value imprinted on the calibration cell relative to the crossbar length you are using Again if your OMD varies from calibration by more than 10 within a range of 1 to 100 PPM it should...

Страница 33: ...33 CALIBRATION ...

Страница 34: ...ater daily to prevent buildup of mineral deposits Recommended Spare Parts There are only two recommended spare parts for the OMD The first is the IR specific halogen lamp which is rated to last one to two years The Heath part number for the lamp is 2510592 The second is a fuse 7 amp SLO BLO 3AG Heath part number 2510569 TROUBLESHOOTING PROBLEM SOLUTION Light won t turn on Check connectors for ligh...

Страница 35: ...curs If it occurs while vehicle engine is off start engine If it occurs while engine is running have your battery and charging system checked by a mechanic Water has condensed on the The receiver has obtained inside of the receiver lens a leak return the OMD to the factory for repair Water has condensed on the The light assembly has inside of the light assembly lens obtained a leak return the OMD ...

Страница 36: ... with contrast up button Ifscreenisstill blankcallTheHeath Customer Service Depart ment Audible alarm not sounding Press and hold speaker for 15 seconds Lower the alarm set point until it s approx two PPM above PRESENT Press CALIBRATION TEST button to test alarm If audible alarm still doesn t work call The Heath Customer Service Depart ment TROUBLESHOOTING ...

Страница 37: ...ent unless due to improper packing It does not cover failures which result from accident misuse abuse neglect mishandling misapplication alteration modification or service other than at a Heath Consultants warranty repair location Heath Consultants responsibility is expressly limited to repair or replacement of any defective part provided the product is returned to an authorized warranty repair lo...

Страница 38: ...ief description of the problem you are experienc ing and specify the person to be contacted for information Customer Assistance and Service Locations If for any reason assistance is required technical or otherwise please contact Heath Customer Service at the following phone number If it is necessary to ship the OMD for service or repair you may use the original shipping box and ship the OMD to the...

Страница 39: ...eath Consultants Incorporated 9030 Monroe Road Houston Texas 77061 Phone 713 844 1300 Fax 713 844 1309 www heathus com MANUFACTURING AND WARRANTY SERVICE FOR THIS PRODUCT Heath Consultants Incorporated 9030 Monroe Road Houston Texas 77061 Phone 713 844 1350 Fax 713 844 1309 SERVICE ...

Страница 40: ...the fol lowing data 1 A map s or lists of main and service locations in the area to be surveyed If maps are used the daily coverage of the survey should be plotted in a color code to establish each day s coverage Large scale maps may be difficult to manage so it is suggested that you attempt to obtain key sheets of the plate maps or small scale maps showing large areas 2 If your orders indicated t...

Страница 41: ...fety and efficiency special consid eration should be given to heavy traffic areas peak peri ods of this traffic and locations of one way streets If possible the heavily traveled streets should be surveyed prior to or after peak traffic flow hours UNDER NO CIRCUMSTANCES WILL THE UNIT SURVEY AGAINST TRAFFIC this procedure is unsafe D Discuss with Your Guide 1 What he knows about the system that will...

Страница 42: ...checked for dirt build up at the beginning of each day If necessary clean with a cotton rag soap and water 2 The OMD will be periodically checked while in use to insure that it is responding to methane gas by pressing the CALIBRATION TEST button B Calibration of Instrument The functionality should be periodically checked by pressing the CALIBRATION TEST button If the OMD is suspected to be out of ...

Страница 43: ... instance of dual mains particularly wide streets or divided traffic lanes a par ticular street should be traversed in both directions In unpaved locations sampling is done as close to the bur ied structure as possible The consultant will use system maps to determine which streets to survey and where the main is in the street As each successive street is surveyed it is recorded on the map and colo...

Страница 44: ...ticular survey will be specified on the survey orders or by the supervisor See the Heath Field Manual for specific instructions for each form specified All areas surveyed shall be desig nated by one 1 of the following 1 Daily Color coding Map 2 Daily Service Line Listing 3 Daily Street Listing IV Classification of Indicated Leakage Areas See also Leak Classification section of Heath Field Manual E...

Страница 45: ... which in the judgement of the consultant requires immediate attention Grade 1 should be reported by telephone to the designated of ficial when detected unless otherwise instructed by the client The time the leak is called in must be noted on the leak report Each leakage area which is to be classified must first be evaluated to determine the extent of gas migration Bar holes must be placed and tes...

Страница 46: ...rdpans tend to limit and restrict the venting process Heavy moisture in this type of soil tends to further restrict venting C Effect of Paving Continuous paving certainly reduces venting of gas from the soil However most paving includes expansion joints and most asphalt paving has cracks depending on its age and gas will vent at these locations Freshly paved concrete and asphalt areas provide very...

Страница 47: ...content and temperature variations Newly fallen snow with low moisture content is loosely com pacted and tends not to inhibit venting As moisture content increases greater compaction occurs which tends to restrict venting If the snow has high moisture content or rain has occurred since it fell followed by subfreezing conditions venting may be considerably re duced Disturbing the surface of the sno...

Страница 48: ...e at such times as the wind velocity is zero M P H miles per hour Very heavy winds on the other hand dilute the sample and disperse the sample in the air In several parts of the country the problem of prevailing winds can be nulli fied by starting the survey earlier in the morning and ending earlier in the afternoon If on a survey where the environmental conditions are hindering his ability to do ...

Страница 49: ...49 APPENDIX A In heavily paved areas special care should be taken to sample as many venting locations as possible including available openings ...

Страница 50: ...where the vehicle can be driven in such a manner as to place the light path of the OMD within the plume of methane that is venting from the ground B What is Inspected Mobile survey provides coverage of mains associated valves regulators and drips the service taps at the main and that portion of the service line located in or near the street alley or area where the survey vehicle can be driven III ...

Страница 51: ...thane gas by pressing the CALIBRATION TEST button B Calibration of Instrument The calibration should be periodically checked by press ing the CALIBRATION TEST button If the OMD is suspected to be out of calibration it should be verified with an external calibration cell If the OMD is verified to be out of calibration it must be re calibrated C Survey Procedures Regular Mobile Survey The survey is ...

Страница 52: ...e indication Results are then recorded and the survey is resumed The client should supply accurate maps to the consultant These will be used to determine which streets to survey and where the mains are located As each successive street is surveyed coverage is recorded on the map and color coded as a record of the daily street coverage D Survey Procedures Patrol Type Survey The patrol type survey i...

Страница 53: ...existing or probable hazard to persons or property and requires immediate repair or continuous action until the con ditions are no longer hazardous 2 Grade 2 B A leak that is recognized as being non hazardous at the time of detection but requires sched uled repair based on probable future hazard Sched ule for repair after Grade 2 locations are completed 3 Grade 3 A A leak that is non hazardous at ...

Страница 54: ...ey and a release form ob tained to confirm receipt These maps are stamped signed and dated as a permanent record of the survey C Street Listings Where maps are not available lists are prepared detail ing the streets and or specific lines surveyed These lists are bound into the final report and returned to the Gas Company upon completion of the survey D Leak Location Report Leak reports indicating ...

Страница 55: ...55 APPENDIX B DRAWINGS 1 INSTALLATION ISOMETRIC 2 INSTALLATION ERROR 1 3 WIRING DIAGRAM 1 OF 2 4 WIRING DIAGRAM 2 OF 2 ...

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Страница 60: ...e Acrobat Reader 3 0 or later you must install Adobe Acrobat Reader 6 0 which is included on the WINCAL CD ROM 1 Insert the CD ROM 2 Double click on my computer 3 Double click on WINCALCD drive 4 Select the Manuals folder 5 Double click on the executable file adbeRdr60_enu_full exe 6 FollowthedirectionsgivenbytheInstallWizard 7 Once you have installed Adobe Acrobat Reader double click either on fi...

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