G-Tech Hp Meter Update

[Bruce Bowling]

> 
> 
> Hello Bruce,
> I read your response and am curious about parts of it. For example the 
> following equation for air density:
> 
>   AirDensity=0.0228645 * barometer(In Hg)/(0.5555* (temp - 32) + 273.15) 
>   
> I understand the barometer and the ((temp - 32) + 273.15) to get degrees Kelvin 
> I'm sure the constants 0.0228645 and the 0.5555 are for unit conversion but how 
> are they derived? Also concerning the next equation:
> 
>   AeroDragFactor = 1.07556 * AirDensity * Coeff_Drag * Frontal Area
> 
> Again the 1.07556 is probably for unit conversion, how is it derived. This is an
> area that always intrigued me. Thanks for bringing up the topic.
> 
> John Faubion
> jfaubion at cs-smtp.tyndall.af.mil
> 
I am under the impression that the constants are empirically-derived. I have
seen these equations many times, but I have not seen a suitable explanation
of their origin.

- Bruce


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               Bruce A. Bowling
  Staff Scientist - Instrumentation and Controls
 The Continuous Electron Beam Accelerator Facility
    12000 Jefferson Ave - Newport News, VA 23602
                 (804) 249-7240
                bowling at cebaf.gov  
        http://devserve.cebaf.gov/~bowling
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