You can use one of these: http://loosnaples.com/how-to-use-pt-series-tension-gauges
Or do it by sound! All you need is a small tape recorder and a 3 ft piece of 2 by 4 lumber. Cut two small blocks off the ends of the 2x4, and nail them to the ends of the long piece, on the side. File or saw a "v" notch in the small blocks, along the long axis, so the guy wires can sit in the notches. This forms two bridges, so that when the 2x4 is placed agains the guy wire, it can be "plucked" to produce a vibration. Now you need to "calibrate the instrument". Take a piece of the same guy wire, hang it from any tree, tower, frame, swingset, anthing you can find overhead that can support about 300 lbs. Form a loop in the guy to put your foot in. If you step in the loop and hang you will tension the guy to your weight. (say about 200 lbs). While under tension, perhaps from a friend, place the 2x4 against the wire, and pluck it like a guitar string. Record the tone on your tape recorder several times. Hint: placing the recorder directly on the 2x4 helps capture the tone. Now, while you tension your tower guys wires, place the 2x4 against the guys, and pluck them in the same way, listening to the tape recorded tone. When the tension is the same as your weight, the tones will be equal. If you want to double the tension to twice your weight (say to 400 lbs), the tone will have to be twice the frequency. There are several ways to do this. One is to make another bridge from a notched block of wood, and place it at 1/2 of the original separation distance. Another (if you have a sound card and microphone) is to use your computer to measure the frequency, and then produce one with twice that frequency with a tone generator. Record that frequency on your tape recorder, and use it in the field for the 400 lb "note" Matt Hoppes Director of Information Technology Indigo Wireless +1 (570) 723-7312 On 8/12/13 1:17 PM, Andris Bjornson wrote: > Hi all, > > I'm looking for a field expedient (read "not requiring fancy tension > meters and special equipment") to evaluate whether guy wires on towers > are undertensioned. > > I'm currently deploying a wireless project in Northern Uganda on > locally fabricated towers. The engineer who built the towers is very > good, and was able to provide structural calculations for each tower. > He does very nice work, and by and large I'm very happy with the > product. > > Someone has mentioned a method to me in the past involving plucking > guy wires and watching the pulse rate....but I didn't get any numbers > on what's good and what's bad. > > Any help greatly appreciated! > > Andris > > > > > _______________________________________________ Wireless mailing list [email protected] http://lists.wispa.org/mailman/listinfo/wireless
