Eddy Flux Tower Mounting Considerations and Suppliers Technical Note #132 Diamond Aluminum Company TECHNICAL NOTE Mounting Hardware Suppliers The following suppliers offer fittings and piping options for mounting a LI-COR analyzer to a tripod or tower. Any metal pipe from your local hardware store can be used with these fittings, as long as they have been properly sized and finished; however, the sources below offer custom piping options for your convenience. For instrument mounting projects LI-COR recommends aluminum fittings and pipes. The pipe sizes and additional fittings depend on your sonic anemometer and setup configuration. The mounting hardware included with the LI-7200, LI-7500A, and LI-7700, however, is designed to be used with a 1 inch pipe. (http://www.diamond-aluminum.com) is a structural aluminum fittings and pipe company that sells a variety of fitting configurations (made of highstrength, light-weight aluminum alloy) and piping (available in 4 different sizes, ordered by the foot and custom cut to fit your needs). Download Diamond's product catalog to learn more about material specifications and unique designs. Diamond Aluminum Company Crossover fittings (http://www.diamond-aluminum.com/fittingpages/ 200.htm) 1.0 in. × 0.75 in. crossover fitting - p/n 200 (PA) Mounting your LI-COR analyzer to a tower (near the sonic anemometer): ● ● ● ● 0.75 in. diameter × 10 in. long aluminum pipe 1.0 in. × 0.75* in. crossover fitting (2) - connects directly to the mounting post 1.0 in. × 0.75* in. crossover fitting 0.75 in. diameter × 12 in. long aluminum pipe LI-7500A Sensor Head *This assumes a 0.75 in. diameter pipe; however you can use any size pipe you would like. Sonic Anemometer Crossover Fittings You will also need: ● 4 ft. crossarm with bracket ● Mounting brackets for LI-7550 Analyzer Interface Unit - dimensions 13.8” × 11.8” × 5.9” (35cm × 30cm × 15cm) Crossarm LI-7550 For use with: • LI-7200 CO2/H2O Analyzer • LI-7500A CO2/H2O • LI-7700 CH4 Analyzer ® LI-7550 Analyzer Interface Unit NuRail (http://www.nurail.com ), of Metropolitan Pipe and Supply Company, offers everything needed to mount your LI-COR analyzer to an industrial tripod or tower. NuRail offers aluminum fittings in a wide variety of configurations and sizes ranging from 3/4 in. to 2 in. NuRail also has a pipe fabrication service for custom made integrated fittings and pipes. Tripod NuRail Crossover fittings ® Crossarm (1”) 1.0 in. × 0.75 in. crossover fitting - p/n 8783 Mounting Post (3/4”) Crossover Fitting (1” x 3/4”) 1 Typical tripod mounting configuration (LI-7500A shown). The mounting post included with the LI-7200 and LI-7500A is 3/4” Diameter. Rohn Tower and Tripod Suppliers (http://www.rohnnet.com) provides towers to communications companies; made of galvanized steel, these towers assure corrosion free use and have the ability to withstand harsh weather elements. The types and sizes of towers vary, from self supporting towers, to guyed towers, to bracketed towers. Sizes range from 10' to 100'. When setting up your LI-COR instrument, depending on what your research needs are, you will need a tripod or a tower to support your equipment. LI-COR does not manufacture these items; however, we do recommend purchasing something similar to the items shown below. Please keep in mind that the tripod/tower must be able to support the weight load of your equipment setup, must be a proper height, and must be able to withstand variable weather conditions. Speak with a representative at the companies listed below to help determine which setup will be right for you. Self-Supporting Towers (http://www.rohnnet.com/rohn-g-series-self-supporting-tower ) ● 10 ft. tower (p/n 25SS010) ● Sizes range up to 80 ft. ● Download the Self Supporting G-Series Brochure for more information Rickly Hydrological Company (http://www.rickly.com) manufactures and distributes instrumentation equipment such as industrial strength tripods and towers for outdoor use. Their durable and weatherproof designs are accurate and affordable, as well as lightweight for easy handling and quick assembly. Guyed Towers (http://www.rohnnet.com/guyed-towers ) ● Best for larger towers Bracketed Towers (http://www.rohnnet.com/bracketed ) ● Best for larger towers Model 3574 - 20 ft. portable tripod (p/n 1002-155) ● Weight= 66 lbs. (30 kg) ● Set-up time = 45 minutes ● Adjustable base legs for uneven terrain Climatronics Corporation (http://www.climatronics.com) offers a variety of weather monitoring instruments and towers. These aluminum towers feature a triangular design, are lightweight and transportable, wind resistant (up to 110 mph), and require minimal set-up time. Towers range in sizes from 10 ft. up to 80 ft. and weigh 13 lbs. up to 247 lbs. (5.9 - 112.3 kg). Model 3576 - 10 ft. portable tripod (p/n 1002-168) ● Weight= 18 lbs. (8.2 kg) ● Set-up time = 10 minutes ● 6 ft., 15 lb. (6.8 kg) option also available ● Each leg can be staked to the ground for added stability ● Best for temporary or quick deployment applications Model # C-10: 10 ft. tower, 13 lbs. (5.9 kg) Model # C-20: 20 ft. tower, 26 lbs. (11.8 kg) Model # C-30: 30 ft. tower, 38 lbs. (17.3 kg) Larger model #'s can be found by downloading the Freestanding Aluminum Towers brochure: (http://www.climatronics.com/Products/Accessories/ meteorological_towers.php ) Model 3578 - 10 ft. Standpipe aluminum tower (p/n 1002175) ● Weight= 65 lbs. (29.5 kg) ● 12 in. diameter pipe offers little wind resistance ● Standpipe serves as protection to electrically sensitive equipment ● Best for long term applications ● LUKSA Industries Inc. (http://www.luksa.com) designs and manufactures mechanically operated aluminum tripods. Tripods are rugged and portable for quick and easy deployments, free-standing with adjustable legs for uneven terrain, weatherproof, and provide excellent stability. Tripods feature a crank-up, fully locking extension system suited to fit your needed height specifications. Options include a 6 ft. tripod which can be extended to a height of 30 ft. (weight is 30 pounds) or a 7 ft. tripod which can be extended to a height of 40 ft. (weight is 35 pounds). For mounting in areas of high wind conditions, the Guy Kit (p/n 101004) provides further tower stability GlenMartin (http://www.glenmartin.com) produces towers and accessories in a variety of sizes from 30 feet to 70+ feet. These towers feature strong diagonal construction to withstand high wind speeds and are durable and maintenance free. Added bonuses: A hinged base system allows for easy installation, a pulley system works as a functioning elevator to raise and lower equipment with no need for tower climbing, and Glen Martin also offers lightning rod tower solutions. HI-VIEW30 Tripod (http://www.luksa.com/hiview.html) HI-VIEW40 Tripod (http://www.luksa.com/hiview.html) 2 M-13 Hazer Towers (SKU M-1330A) 30' Hazer Tower Package ● Preassembled ● Weight= 370 lbs. (168 kg) 40' Hazer Tower Package (SKU M-1340A) ● Preassembled ● Weight= 415 lbs. (188.6 kg) 50' Hazer Tower Package (SKU M-1350A) ● Preassembled ● Weight= 450 pounds (204.5 kg) Tripod/Tower Lightning Protection Eddy covariance flux tower systems are typically exposed to variable environmental conditions. Thus, it is very important to have proper lightning protection. There are four main parts to any grounding system: 1) lightning rod; 2) grounding plane; 3) grounding wire, and 4) the bond between them. Further details, guidelines, and suggested lightning protection providers are listed below. The Grounding Plane The best grounding planes are: ● Copper or copper- clad ground rods driven into the earth ● Copper water pipes or building grounds with metal structural frames ● Metal enclosures and casings (which should be grounded to earth ground) Download the product catalog for more information about these towers, accessories, and options at: (http://www.glenmartin.com/amateur.html). Tower/Tripod Guying and Anchoring Equipment Freestanding towers and tripods are exposed to a variety of environmental conditions, one of which is the potential for high wind speeds. To ensure that your tower remains upright, guying cables and anchors should be used. The companies listed below offer anchoring solutions for securing flux towers. Grounding rods should be either copper or galvanized steel ● Minimum diameter of 5/8 in. Note: Aluminum should not be used as a grounding rod, as the alkalinity of the soil will etch the metal, causing disconnection and in increase in impendence between the grounding system and earth ground. Foresight Products, LLC (http://foresightproducts.com/duckmain.html) is a manufacturer of earth anchors for all types of applications. Duckbill earth anchors require no digging, concrete, or holes, making them a reliable and time saving device for safely anchoring your tripod to the study site. This company offers effective, lightweight, and economical anchoring solutions with excellent holding capacities. The Grounding Wire ● ● Use heavy wire gauges (10 AWG or larger) for running the grounding wire The cable can be solid or stranded, the wire can be either bare or insulated The Bond between them Multi-purpose: Model 88-DB1 ● 3,000 lb. (1364 kg) anchor holding power in normal soil ● Cabled with 3.5 feet of 1/4 inch galvanized aircraft cable * You will need the DS-88 Drive Steel to install the anchor ● ● ● GlenMartin (http://glenmartin.com/catalog/page17.html) is a tower infrastructure solutions provider that sells commercial selfsupporting and fold-over tower systems, amateur radio towers, guying accessories and lightning protection. In addition, GlenMartin offers complete manufacturing, engineering, warehousing, transportation, and construction services. The use of dissimilar metals between the surge protection device and the grounding plane should be avoided Ground clamps should be used to bond the grounding wires to the grounding plane Both copper and aluminum are approved for use in grounding protection systems; however, copper is a better conductor of electricity and can be used in smaller gauges Proper Installation Guidelines ● ● Item # ES-40 ● 2,500 lb. (1136 kg) anchor holding power in normal soil ● 30" anchor length * You will need to purchase guying cable separately * Item # WRS-250: 1/4 inch cable with 1280 lb. (582 kg) working load ● ● Do NOT sharply bend the surge protection wires during termination; offer a straight path to the ground Keep the surge protection wires as short as possible to improve effectiveness and response time Keep the surge protection device a few feet away from the equipment to allow proper response time for the transient voltage to be suppressed Ensure all systems connect to the same grounding point only ONCE Reference: http://www.ul.com/global/documents/corporate/ aboutul/publications/newsletters/electricalconnections/ july09.pdf 3 Suggested Sources: 1. Glen Martin Lightning Protection Package (http://www.glenmartin.com/catalog/lightning.htm) ● A complete kit which provides everything needed to protect your tower and instrumentation against damaging lightning ● p/n LR-8400 2. Radio Shack (http://www.radioshack.com ) 3. Thompson Lightning Protection (http://www.tlpinc.com/TLPProfile/products.htm ) ● Best for commercial use 4. Local electronic supply company ® 4647 Superior Street • P.O. Box 4425 • Lincoln, Nebraska 68504 USA North America: 800-447-3576 • International: 402-467-3576 • FAX: 402-467-2819 • envsales@licor.com • envsupport@licor.com • www.licor.com In Germany and Norway – LI-COR Biosciences GmbH: +49 (0) 6172 17 17 771 • envsales-gmbh@licor.com • envsupport-gmbh@licor.com In UK and Ireland – LI-COR Biosciences UK Ltd.: +44 (0) 1223 422102 • envsales-UK@licor.com • envsupport-UK@licor.com 75H-106, 7/10