1. #1
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    Question Natural Gas Detection Meters/Equipment

    Hey Everyone

    So, I have a question for everyone. What are you guys carrying on your rigs for Natural Gas Leak Detection? Currently we carry a BW 4 Gas meter. Id like to get a meter just for the detection of Natural Gas and wanted to get a feeling from everyone if they feel its a needed piece of equipment, and if so if you have any recommendations on what to get? What equipment you've used in the past and what you did and didnt like about it. Thanks again for all your help.

    -Chris
    http://www.eastmeadowfd.com

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    We also have a four gas detector but the one I use for finding the leak is a GasTrac combustible gas indicator. It uses an audible tick rate to let you know when concentrations increase or decrease.(similar to a geiger counter) It is far more sensitive than the four gas detectors so it is very good for narrowing in on the specific pipe joint that is leaking. When I go in on a natural gas call I bring in the four gas and the GasTrac. I am back on tomorrow so I will see if I can get any more info on the device.
    Sometimes, in order to make an operation idiot proof, you must remove the idiot!

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    We are using the GasTrac CG detector, but also have access to a MultiRae Multigas detector with the PID.
    Shawn M. Cecula
    Firefighter
    IACOJ Division of Fire and EMS

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    What are you attempting to accomplish? Finding an actual leak or atmospheric monitoring? It is important to include oxygen when atmospheric sampling, first for the crews safety and second to ensure that your LEL readings will be correct. Finding the leak can sometimes require low level monitoring equipment. BW just came out with four gas with built in PID, the Scott Scout begins measuring in PPM and then switches to percentage in air as it increases and also has a PID and the Scott TLV measures from 0-10000 ppm of combustibles (old technology but works great for the purpose) For just straight up leak detection Scott has a leak detector that was described previously as a Gas Trac, I think it is the same type of device, adjustable, led's only and an audible rate meter.

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    While the PID is great for most volatile organics, you really need to check your book to see which products it will not detect. The 10.6 electron volt lamp is the most common and from what I remember it does not work for methane. I don't have the book in front of me but I will check it when I am back to work.

    Halligan, you are absolutely right about the oxygen detection. This is why we always bring in the 4 gas and the Gas Trac. Having an oxygen sensor can tell you much more than simply the amount of o2. If you notice even a 0.5% drop in o2 then you can suspect that there is potentially 0.5% (5000ppm) of something else displacing it.
    Sometimes, in order to make an operation idiot proof, you must remove the idiot!

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    You are correct that the IE of Methane is 12.61eV. However the remaining constituents of Natural Gas would make it possible to detect with the PID. Sidestepping the issue I know. Generally we use the Gas Trak. The variable gain is useful, however I would like to know the %LEL rather than hear that the level is increasing.
    Shawn M. Cecula
    Firefighter
    IACOJ Division of Fire and EMS

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    The two work well together. Knowing the percent LEL is great when you have enough to register on the equipment. That is where the GAS TRAC works well. At very low levels you can detect a slight increase in gas levels which will help to find the source. Then at higher levels, knowing the %LEL gives you a numerical value to work with. I don't think any one detector does everything well.

    On a somewhat related note. Since no single device covers everything, we are often carying multiple devices in to the call. Have any of you come up with a creative way to carry all your instrumentation into calls?
    Sometimes, in order to make an operation idiot proof, you must remove the idiot!

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    Originally posted by Halligan84
    What are you attempting to accomplish? Finding an actual leak or atmospheric monitoring? It is important to include oxygen when atmospheric sampling, first for the crews safety and second to ensure that your LEL readings will be correct. Finding the leak can sometimes require low level monitoring equipment. BW just came out with four gas with built in PID, the Scott Scout begins measuring in PPM and then switches to percentage in air as it increases and also has a PID and the Scott TLV measures from 0-10000 ppm of combustibles (old technology but works great for the purpose) For just straight up leak detection Scott has a leak detector that was described previously as a Gas Trac, I think it is the same type of device, adjustable, led's only and an audible rate meter.
    A combination of both. Recently we had a gas leak at a senior complex. Our 4 Gas BW meter showed %LEL in some areas (close to the leak) but not the others, made it very difficult to find the actually source (which ended up being outside in a transformer vault). After which we had to go from apt. to apt checking for any leftover NG. One of Departments that came in to help had one of the meters just for Natural Gas and was able to detect leftover gas in apartments that was not picked up on the BW (Guess because it wasn’t in High Enough Concentration). Our district also covers a good deal of commercial with rooftop gas fired A/C's and Heating units. At least once a month we go to a smell of gas in the building and find out its on the room. Normally we shutdown the gas for the entire roof as these units tend to be close together. Getting the right equipment will hopefully allow us to find the unit that has the "leak" and shut that one down and not turn off ac to the other 7 floors in the building. Thanks to everyone thus far for your feedback. The powers to be are off to Balt next week and will be looking to purchase equipment and your suggestions have helped point them in the right direction.

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    If you want to pinpoint a leak an FID makes a great bloodhound and unlike a PID it does detect methane. In addition to multi-gas, PID's and FID's we also carry a TVA 1000 which is both a PID & FID. This combo is great for gas odors of unknown type. If the FID is registering but the PID isn't then you can be confident that you are dealing with methane. If both are registering you most likely have propane. I won't say "definite" for gas type because there could always be something else in the air hitting the PID. Just remember there are some FID's out there that are not intrinsicly safe.

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    Thanks everyone for your information so far. We are currently trying out a number of the SCOTT Scouts for the next 30 days. Multi Gas Models, Single Gas Models and PID Model.

    -Chris

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    I think I know what you are looking for along with your 4 gas detector. This is an inexpensive gas detector which will let you pin-point leaks as well as notify you of a presence. The gas company uses it so it must be okay.

    Gas Leak Detector Kit
    Combustible Gas Leak Detector Kit, With Visual Leak Size, Includes Sensing Tip, 115 Volts Battery Recharger, 2 Nickel Cadmium Batteries, Carrying Case

    Grainger Item: 1TC18
    Price (ea) : $240.00

    http://www.grainger.com/Grainger/pro...625931&ccitem=

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