Well, i know this is a very random question. But one day, i borrowed a eagnas calibrator from my doubles partner.( He is a much experienced stringer than i am). So i happily brought it home and tried it on. But to my horror, the tension gauge on my machine was quite different on the measurement on the eagnas calibrator, so i quickly rang up my doubles partner to ask why is this so.) So we discussed and discussed, and we came to a conclusion, If a calibrator calibrates a stringing machine, what calibrates the calibrator. (I am not saying that my machine is accurate, just curious on this topic.) I know this question is just like the question on which comes first, Egg or Chick? But i just want to know what you guys think. Thanks alot for your replies guys.
This used to be 1 of the question I post for the extra credit to the student while I was in lab. What I will suggest you is to get 2 bottles of 2 liter soft drink. That is totall of 4 kg give and take a few grams off. Reset the calibrator and hook the 2 bottles on a string and that will give you 4 kg of tension. If you want to test something higer, jet get 2 more bottles of drink and you get 8 kg. That is enough soft drink for you for the next 2 weeks.
I like this sort of question - I once asked my uncle, a driving instructor, who had instructed him in the art of instruction... and so on ad infinitum. There are two possible answers that I can think of: 1. There exists, somewhere, some "master" calibrator which is kept in an impenetrable bubble, and all commercial calibrators are tested against this one. This isn't without precedent, as meteorological equipment (thermometers, barometers, etc) and precision measuring apparatus are often set this way. 2. More likely, the manufacturing process for calibrators is so rigid and precise that Eagnas et al just don't bother checking them. They really are simple to make - they only consist of a spring inside a tube and a protruding, graduated rod - so there isn't a lot of room for error.
But the thing is, the calibrator also uses a spring. As you know, springs has a parabola graph when u pull them, when u stretch to a certain extent, the spring will be able to stretch easily. So, using a 4Kg bottle might not help.
So can i conclude that they actually manufacture the calibrator just to make some extra bucks? The calibrators are just some business gimmick?
F= C x U The extension is the force divided by the springconstant. It's linear..at least, for the first 300pounds or more After that they start to deform plastically (different topic)
Based on how much we get charged for them, yes! I've seen digital fishing scales that are cheaper, more accurate, and have a wider range of readings than machine-specific calibrators - so what are we actually paying for? The Eagnas sticker?
So I'll have to buy another calibrator whenever I want to go over 300lbs?!?! I'm being RIPPED OFF left right and centre!
yes it is possible... but the (steel?) springs used in current calibrators are less than 5mm thick (the wirethickness). at higher tensions (way over our 20-35lbs) the steel will deform plastically and give weird readings...Not to mention you can just throw it away afterwards Anyway, the point I was making was that our calibrations are all in the elastic zone of the spring, so its "calibration" (stretching) is linear (post #6). Now, if you keep on the tension long enough, It will creep..but that's a different topic.. Btw, very witty Steve
I heard from it from one my "kakis" before. But why need a string tension measurement tool when u can depend on your own experience?
only for tennis rackets http://www.watdon.com/WA322.gif badminton strings are too thin, and can't flex enough for a reading... so sound is your best bet (tap it, listen to the tone),you'll get the hang of it
