I am looking forward to setting up my own WEATHER-FLOW STATION and I am following the best way to mount my unit. I am thinking about putting it either on an old television antenna tower or mounted on a pole in the middle of my yard.
How high should I place the unit above the roof “peak” which will be about 20 feet west of the units location? My home is a ranch style with the roof peak running north to south. Another location I am considering would be on top of my barn, with the roof line running east and west, However, there is a line of pine trees to the north of the barn that may affect the wind readings.
Air has to sit in the shade and well-ventilated location
I think your question is focusing on the Sky:
Wind detection needs a free line of view to all directions
and
space to the next object below hence, these will disturb the flow profile.
Rain sensing is commonly done next to the ground (i.e. at 1 m)
for light (UV) sensing, surrounding objects should not cause shadows onto the Sky.
If you mount on an east-west orientated roof or a south-north that one will not play a role.
For Sky, it is important to mount it on a fix (not vibrating, moving or wobbling) mount (in other topics you’ll find many hints).
For the place of your Sky, you have to answer the question about what do you compare the data to and what is your focus set onto : wind, rain or UV/light intensity.
The Sky measures wind and rain (and sunny stuff) but has difficulty measureing both accurately depending on the mount.
If rain is important it is most important there are NO vibrations from the pole.
If wind is important it has to be as high with clear view 360 deg.
It is difficult to stop vibrations on a tall pole but not impossible.
There are several discussions regarding vibration causing false rain reports. Here is one: https://community.tempest.earth/t/rain-sensor-and-vibrations/1345
Look at this topic for ideas:
After doing some brainstorming (sorry, storms happen) I had thought about using mineral oil as a damper medium within the pipe in order to eliminate vibrations. Mineral oil is used in different gauges in order to stabilize needle movement, plus as an added benefit the pole would not rust on the inside.
After doing some go-zentas I figure it would require about 5 quarts of oil to fill a pipe 30 ft long and 1" in diameter mineral oil would be a good choice and is about $20.00 a gallon. One could use less expensive motor oil but that ain’t good for the environment. any thoughts, good or bad?
Sand mostly just adds more mass and changes the resonant frequency. There was a paper done some years back about how amateur astrophotographers should build piers for their telescopes to minimize vibrations that would impact long-duration image acquisition. Pier Design Fundamentals - How to . . . - Articles - Articles - Cloudy Nights if you’re interested.
His analysis is to think about a pier as an inverted pendulum that’s bolted to the ground. Adding more weight makes it more likely to have lateral movement due to forces. The popular wisdom as demonstrated by hitting your telescope pier with a hammer and noting that it rings less after adding sand was wrong. First, you lowered the resonant frequency so it doesn’t ring like it before, and second, stop hitting your telescope pier with a hammer That’s not what causes it to sway - wind and similar forces do. His recommendation for that use-case was a larger diameter pier which is stiffer, by a factor that went with the square (I think) of the diameter.
I think filling your mast with sand is only going to make it sway more. Maybe using something like Sorbothane Sorbothane - Wikipedia would be useful as an isolation means could help. I’ve used that for portable telescope piers to isolate vibration of people walking around on the ground from being couple to my telescope set-up on the ground surface. That seemed to work for impulse vibration inputs, not sure what the source of the vibrations in a Weaterflow system are that you’re trying to mitigate.
As you can see in the video I linked in this post: Photos of Air and Installation it isn’t the swaying or low frequency vibrations which are the problem. Dampening the higher frequency vibrations which can fool the haptic sensor into thinking it is a rain drop is what has to be eliminated.
widely used in high end audio installations very efficient method of dampening when used with alloy or metal speaker stands or equipment racks , no audio enthusiasts appreciates the bass reverberating and causing a distorted sound…also reverberated sound i.e wind resonates enough sound to cause vibrations . use beach sand if your in driving distance of a beach … however what this wont do is prevent false rain from extreme constant winds /gust hitting the perimeter of the rain area. wind itself is a force any wind tunnel turned up will reveal this flaw in the design… ask my friend mehmet he basically is begging for a switch when the winds hit that sweet spot 60kmh or more . unfortunately i no longer use any weatherflow stuff but curious of the new tempest on how it performs under those weather conditions 60-80kmh time will tell when they in wide circulation .
and totally off topic whilst im here how is the corona virus impacting the production of the forthcoming tempest ? having just read an alarming article on the impact of the electronic supply chains many big companies expecting an impact on supply for upcoming product releases or replenishments of current products…
feel free to split it to somewhere we can all read it @eric
That’s not what causes it to sway - wind and similar forces do. His recommendation for that use-case was a larger diameter pier which is stiffer, by a factor that went with the square (I think) of the diameter.