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RE: Measurement Errors was ( More Coupling...)



Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Mddeming-at-aol-dot-com>



Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-uswest-dot-net>
" <couturejh-at-worldnet.att-dot-net> 


Terry - 

I am pleased to see that coilers on the Tesla List are taking more interest 
in TC testing. However, it should be noted that comparing test measurements 
with computer results can be misleading unless the "error problem" is cleary 
understood. 

1. All real world TC measurements have a certain algebraic (+/-) error. This 
error can be reduced but not eliminated by making several careful 
measurements. 

2. If a computer is working properly the calcs and outputs are always 
correct for the inputs used. It is the inputs that are in error, not the 
outputs. This means all inputs involved must be carefully measured. 

For example if your measurement (oper freq) is 5% too high and the computer 
output is 5% too low, the difference is 10% but they can be both considered 
correct if the error is stated. The true value is somewhere between the 
measured value and the computer value. The computer inputs obviously have a 
total algebraic error that equals a low 5%, very confusing?? 

It is obvious that coilers should use accuracy estimates with great caution. 
Comments welcomed. 

John Couture 

Snip! 

John, Terry, et al 

      Yes! Error estimates are critical to any serious scientific 
calculation. Unfortunately, such considerations seems to be as much anathema 
to many Coilers as the use of Spell Check or other proofreading of e-mail. 

      However, for those who are interested in such things as the Hows and 
Whys of Measurement accuracy and its effects on conclusions, I would 
recommend: 

1)    Beers, Yardley Introduction to the Theory of Error   Addison-Wesley 1958

2)    Richards, J. W.  Interpretation of Technical Data   Iliffe Books Ltd. 
1967 
3)    Taylor, John R. An Introduction to Error Analysis University Science 
Books 1997 
4)    Zeleny, A. & Erikson,H.A. A Manual of Physical Measurements McGraw-Hill 
1937 

Yours in the Light, 

Matt D.