Re: Weather Station and Lighting

First, even demonstrated in professional papers, blunt rods
are superior to pointed. Putting points on that rod
accomplishes nothing. Second, many use 4+ mm cables to earth
lightning. Third, resistance is not the relevant parameter as
is well known to those who first learn the science. Fourth,
direct lightning strikes are typically so trivial that even
well over 95% of direct struck trees leave no appreciable
indication. Properly earthed rods make damage even less
likely.

Many somehow just know things without first learning
science. They observed a rare exception to the typically
struck tree. Using junk science reasoning and widespread
rumor, they assume nothing can protect from direct lightning
strikes. These fanatics will even deny what Ben Franklin
demonstrated in 1752. Routine to suffer direct lightning
strikes without damage. If soil is conductive, then one 3
meter copper ground rod may be sufficient earthing. More
rods, a field of buried wires, or an Ufer ground means
superior protection.

Also known from generations of experience even pre-dating
WWII. Lightning damage is so easily eliminated as to be
considered directly traceable to human failure. Protection is
routine, well proven, and based in the quality if that earth
ground.

Dave says:
> The idea of several sharp points is to let the charge leak
> off in a controlled manner rather than catastrophically
> form lightning.
Such Early Streamer Emission (ESE) devices were so
disrespected as to be rejected by reputable standards
committees. In the States, ESE manufacturers even threatened
to bankrupt the non-profit National Fire Protection
Association using lawsuits because the NFPA would not accept
their proposed NFPA 781. And rightly so. Proposed without a
single scientific fact or experiment to support their myths.
ESE devices are promoted like miracle alternative drugs -
without facts or proof - and with examples of failure they
would rather not discuss. Never let one who recommends ESE
devices become a source of recommendations and logical
reasoning. ESEs are a classic example of junk science and
snake oil.

And then we go one more step - cite sources- Dissipation
Arrays and pipe cleaners, do they work?:
http://www.polyphaser.com/ppc_TD1020.aspx

Some first learns facts before posting junk science
speculations. Those who would recommend ESE devices earn such
caustic comments. It is that irresponsible.

Lightning protection is well proven both in theory and
experimentally. It's about earthing a direct strike without
damage even to the protection system.

Dave Liquorice wrote:
> You want to illuminate your weather station? Well if it floats yer
> boat...
>
> On 2 Dec 2005 20:03:53 -0000, Adrian D. Shaw wrote:
>> Why "as short as possible"? As far as I can see, so long as it's
>> making a good electrical contact with the ground ...
> Lightning is funny stuff it takes the path of least resistance. Note
> that the word resistance is not used purely in the electrical sense.
> Lightning does not like going round corners and will carry straight on
> even out of nice thick bit of copper if it wants to. Remember it has
> just jumped several hundred feet from the cloud, an extra few feet is
> hardly here or there...
>
> I'd go with the suggestion of extending the support pole well above
> the instruments and fitting a nice sharp spike on the top bonded with
> at least 25mm^2 cable to a good solid buried earth plate at the pole
> base. Might even make the top of the spike have several sharp points.
> The idea of several sharp points is to let the charge leak off in a
> controlled manner rather than catastrophically form lightning.
>
> Even then I'd expect to have to replace everything (including the
> pole) if it was struck. Probably easier to make sure your insurance
> cover is good enough.
.

Relevant Pages

  • Re: Lightning Damage
    ... Lightning is not DC where you worry about the resistance but a complex waveform that requires a low inductance and is treated as a R.F. problem. ... Some of the early work on lightning protection came from measuring the rise time on strikes to the Empire State Building with low bandwidth cathode ray tube oscilloscopes. ... In a metal building lightning rods may not offer additional protection as the building itself is the lowest impedance structure. ...
    (sci.astro.amateur)
  • Re: Lightning Damage
    ... Lightning rods containing radioactive materials are called Early ... connection significantly shorter than paths via electronics. ... Dan discusses a 70 degree cone of protection. ...
    (sci.astro.amateur)
  • Re: Lightning & Bathtubs
    ... Reasons posted were same reasons promoted the ESE protection ... That industry says pointed rods that discharge air will then ... prevent lightning. ... Lightning seeks the better earth ground - that plumbing ...
    (alt.home.repair)
  • Re: Lightning & Bathtubs
    ... Reasons posted were same reasons promoted the ESE protection ... research demonstrates that blunt rods are better ... lightning rod is made effective by its earthing. ... Lightning seeks the better earth ground - ...
    (alt.home.repair)
  • Re: MT nightmare
    ... rods are not protection. ... protection - earth ground. ... Lightning seeks earth ground. ...
    (sci.med.transcription)
Loading