WXforum.net
Weather Station Hardware => Ambient Weather and Ecowitt and other Fine Offset clones => Topic started by: raffaello.dimartino on August 07, 2020, 12:44:45 AM
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Me and @mauro63 want to present a simple but effective modification to improve the performance of the WS80.
We simply propose to color the plates of the WS80 appropriately, as many solarshields do.
The performance improvement can be seen on the graphs shown in my article.
https://www.kwos.it/joomla/en/articoli/149-modifica-dello-schermo-solare-della-ecowitt-ws-80 (https://www.kwos.it/joomla/en/articoli/149-modifica-dello-schermo-solare-della-ecowitt-ws-80)
(https://www.kwos.it/joomla/images/ecowitt/WS80-solar-shield_mod1.jpg)
Certainly, a professional coloring, carried out directly from the factory, would make the data of the many Ecowitt, Ambient and FineOffset stations more uniform but we do not know if it will ever be possible.
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An excellent article and good experiment!
Looking at the WH65 (Tri-wing sensor array) construction, I believe the principle can be applied to that also to improve the radiation screen performance.
I shall certainly consider experimenting likewise once I have my WH32-EP as I shall be happy to experiment with either my WS80 or WH65 screens.
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Thanks to Raffaello for the support during this improvement and for the article, very useful!
I can confirm good improvements in performances, more evident in the first morning hours when the sun is low on the horizon but, at the same time, less temperature overestimation in the middle of the day respect to my Meteoshield Pro reference solar radiation shield.
whit this kind of improvement actually, my ws80 has the same or a little better performance against my passive Davis Vantage Pro 2 weather station.
This kind of solution is now in checking phase by Ecowitt to establish it could be applied to standard production or as an aftermarket upgrade
Mauro
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Today results, sht35 on Meteoshield Pro vs Vantage Pro 2 vs ws80 modified
from 10 AM to 10 PM
Mauro
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@raffaello.dimartino thanks for the post and your article. This is a great idea and it’s good to see it really improves the readings. I have a 2 month old tri-wing sensor array with the same shield and if it wasn’t still in warranty I’d definitely try this.
Mine gets full sunshine throughout the day and like you found it was reading slightly too high when the sun was shining on it. I wanted to do something to help the accuracy but because it’s still in warranty I didn’t want to do anything permanent that would invalidate it. So I bought a cheap plastic bowl, cut a hole in the bottom of it so it fits over the existing radiation shield, spray painted it gloss white on the outside and matt black on the inside and drilled several air holes on what would be the north and south sides once affixed to let any warm air vent out.
I put the bowl over the radiation shield and rotated it 90° so it sits on it, then wedged a couple of tooth picks between the bowl and the rain gauge to stop it moving and to create a small ventilation gap at the top. It’s a bit Heath Robinson but it's non-destructive to the station.
So far it seems to be working well. For comparison, l have my old Netatmo sensor in a home-made FARS sat in semi-permanent shade behind the house and I’m only getting an increase of 1-1.5°C with this setup and most of that is radiated heat from the siting, as I have a deck, fence and asphalt car park close. Even with those variables I’m getting pretty realistic values for the site.
Hopefully this helps anyone who doesn’t want to do anything permanent to their array. Once mine's out of warranty I’m going to try the mod directly to the shield to see if that improves things further.
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Yesterday results ;)
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Mauro
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@mauro63 what’s your siting setup? Wondering if you find this helps with radiated heat as well as direct sunlight
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@mauro63 what’s your siting setup? Wondering if you find this helps with radiated heat as well as direct sunlight
Thanks,
my setup is on grass, in a partially open field, elevation 35 mt MSL, in front of Adriatic sea
about the improvement, I can admit that the major impact is with reflected solar radiation and radiated heat from the ground
generally, the improvement of the performances is present during all the day.
You will see my graphs only fro 10 AM to 24 PM, my weather systems are absolutely close each other, with the same height and same exposure, but, due to a new little building, that I'm trying to remove because not authorized, I have a delay during the first morning hours, and I want to post only data with the high quality possible, and with all the systems in identical conditions.
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Mauro
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Fantastic set up, so many Meteoshields :shock:. I’m incredibly jealous!
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Fantastic set up, so many Meteoshields :shock:. I’m incredibly jealous!
Please, jealousy is the last thing I want anyone to feel!
I admit, the Meteoshield is the passive screen that has given me the greatest satisfaction, I don't like the ventilated ones, and the Meteoshield Pro is the only passive one that has performances comparable to a forced ventilation screen but without all the defects of the latter.
Due to the fact that I make a lot of tests for some companies, I need to have a great redundancy of my data, this the reason for the great number of screen
the image is not updated, now I have on test the new Meteorain, a very high-quality rain gauge by Barani Design, connected to a Meteohelix Pro and to a pulse counter, at the same time I'm testing the new Meteowind IoT that you can see on the images
Mauro
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Yesterday results
[ You are not allowed to view attachments ] [ You are not allowed to view attachments ]
Mauro
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Fantastic set up, so many Meteoshields :shock:. I’m incredibly jealous!
Please, jealousy is the last thing I want anyone to feel!
I admit, the Meteoshield is the passive screen that has given me the greatest satisfaction, I don't like the ventilated ones, and the Meteoshield Pro is the only passive one that has performances comparable to a forced ventilation screen but without all the defects of the latter.
Due to the fact that I make a lot of tests for some companies, I need to have a great redundancy of my data, this the reason for the great number of screen
the image is not updated, now I have on test the new Meteorain, a very high-quality rain gauge by Barani Design, connected to a Meteohelix Pro and to a pulse counter, at the same time I'm testing the new Meteowind IoT that you can see on the images
Mauro
Hi is there a separate page on the Meteowind IoT as I'm interested in buying it but got some questions
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Fantastic set up, so many Meteoshields :shock:. I’m incredibly jealous!
Please, jealousy is the last thing I want anyone to feel!
I admit, the Meteoshield is the passive screen that has given me the greatest satisfaction, I don't like the ventilated ones, and the Meteoshield Pro is the only passive one that has performances comparable to a forced ventilation screen but without all the defects of the latter.
Due to the fact that I make a lot of tests for some companies, I need to have a great redundancy of my data, this the reason for the great number of screen
the image is not updated, now I have on test the new Meteorain, a very high-quality rain gauge by Barani Design, connected to a Meteohelix Pro and to a pulse counter, at the same time I'm testing the new Meteowind IoT that you can see on the images
Mauro
Hi is there a separate page on the Meteowind IoT as I'm interested in buying it but got some questions
https://www.wxforum.net/index.php?topic=39613.0
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yesterday results
this time the Vp2 has had a little better performances, worst than other competitors but better than previous days, helped by a good wind during the mid part of the day
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Mauro
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Hello from Spain, I have bought a console with WH65 sensors, I have it installed in the middle of a farmland, in my observations I have problems, I see that the minimums are about 1 degree lower than my reference station, and the maximums too 1st grade, do you recommend painting the plates black on the bottom? On the other hand I am thinking of covering the upper hole of the radiation shield with something white and opaque, it has two holes, from the top you can see the sensor, I think this is not good. What do you think? Greetings
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First of all a couple of questions:
what provides your reference temperature reading and where the temperature sensor is located?
The difference in 1°C may come from the location of the sensor and not from the quality of the sensor screen.
There are micro-climates ;)
But you can do the coloring/painting anyhow. Top-side white and bottom side black as in the first picture.
The WH65 is a 7-in-1 sensor array and as such always a compromise for rain, wind and temperature readings,
as the optimal location, also defined by the metereological services, for each of these observations is different.
You usually position it high for best wind (10 m above ground) readings whereas for rain 1.5-2 m above ground is considered ideal and for temperature 2 m above ground.
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What can I say... you are a good observer ( I never noticed it ).
The sensor board ( behind the filter ) is clearly 'in sight' trough those grooves ( not the greatest idea from ecowitt )
I think these grooves are to help remove water/condensation, but practical realization is quite poor.
If accurate T/H readings are important for you, I think a wh32 sensor in a proper radiation shield could give better results.
In addition when comparing two sensors you should somehow 'align' them ( so to remove the offset between them )
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First of all a couple of questions:
what provides your reference temperature reading and where the temperature sensor is located?
The difference in 1°C may come from the location of the sensor and not from the quality of the sensor screen.
There are micro-climates ;)
But you can do the coloring/painting anyhow. Top-side white and bottom side black as in the first picture.
The WH65 is a 7-in-1 sensor array and as such always a compromise for rain, wind and temperature readings,
as the optimal location, also defined by the metereological services, for each of these observations is different.
You usually position it high for best wind (10 m above ground) readings whereas for rain 1.5-2 m above ground is considered ideal and for temperature 2 m above ground.
My reference station is one of the state irrigation system, I have it in a straight line 600m away and at the same altitude, the land is flat, cultivated. You can see the picture with the specifications. Is a good sensor and protection? it is my reference
currently my station (WH65) is raised on a 4m mast, since in the lower part there is planted corn that reaches 2m, you can see the picture.
The question is what can I do to make the data as accurate as possible, so I can see it in real time with my mobile, the irrigation system station shows the data the next day.
Do you recommend me to paint the plates below black?
I'm thinking of covering the holes in the protector with shiny white glue. Has anyone done it?If the protector is seen from the outside, solar radiation enters it.
Greetings
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@raffaello.dimartino thanks for the post and your article. This is a great idea and it’s good to see it really improves the readings. I have a 2 month old tri-wing sensor array with the same shield and if it wasn’t still in warranty I’d definitely try this.
Mine gets full sunshine throughout the day and like you found it was reading slightly too high when the sun was shining on it. I wanted to do something to help the accuracy but because it’s still in warranty I didn’t want to do anything permanent that would invalidate it. So I bought a cheap plastic bowl, cut a hole in the bottom of it so it fits over the existing radiation shield, spray painted it gloss white on the outside and matt black on the inside and drilled several air holes on what would be the north and south sides once affixed to let any warm air vent out.
I put the bowl over the radiation shield and rotated it 90° so it sits on it, then wedged a couple of tooth picks between the bowl and the rain gauge to stop it moving and to create a small ventilation gap at the top. It’s a bit Heath Robinson but it's non-destructive to the station.
So far it seems to be working well. For comparison, l have my old Netatmo sensor in a home-made FARS sat in semi-permanent shade behind the house and I’m only getting an increase of 1-1.5°C with this setup and most of that is radiated heat from the siting, as I have a deck, fence and asphalt car park close. Even with those variables I’m getting pretty realistic values for the site.
Hopefully this helps anyone who doesn’t want to do anything permanent to their array. Once mine's out of warranty I’m going to try the mod directly to the shield to see if that improves things further.
[ You are not allowed to view attachments ] [ You are not allowed to view attachments ]
Hi
I don't think this solution works well, or am I wrong? do you have comparative data?
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@servilla It depends on your circumstances. Mine was overheating in direct sunlight and this has definitely helped.
As @Gyvate pointed out, there will always be a compromise with all-in-one arrays. Only thing to do is test different options and see what works for you. My bowl method is non-destructive (unlike painting) so you could start with something like that.
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The question is what can I do to make the data as accurate as possible, so I can see it in real time with my mobile, the irrigation system station shows the data the next day.
Do you recommend me to paint the plates below black?
I'm thinking of covering the holes in the protector with shiny white glue. Has anyone done it?If the protector is seen from the outside, solar radiation enters it.
Greetings
You want it as accurate as possible - get yourself a separate WH32 or even WH32-EP sensor and put it into a good radiation shield. (e.g. Davis 7716, MeteoShield Pro).
The low-cost solution is painting the down-side of the plates black and the up-sides with a reflecting white (as described earlier).
I would refrain from closing holes - this might be counter-productive as this could restrict proper and needed air circulation.
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Hi - could someone explain to me the theory for colouring the inside and ground facing surfaces matt black.
also should the bottom plate be black as other manufacturers have the bottom plate white.
another thing should the bottom of the array above the shield plates be coloured black.
Thanks.
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as far as I know is the theory behind the black clour coating that solar (ir-)radiation will be kept from entering the shield which would/could be possible when reflected by the white parts. This is only for the staggered "tiles". The openings. Painting the bottom black would be counterproductive as it would absorb heat and heat the whole piece. The same is true for the piece above the T/H sensor portion.
The company Barani Design has made a science out of it - with great success. They have combination of painting and construction design which has produced one of the most efficient non-actively-ventilated radiation shields available these days (expensive though).
My personal observation is however that the shielding of the WH65/WS69 and WS80 arrays is pretty good - compared to a single high precision T/H sensor inside a Barani MeteoShield. But painting the underside of the opening black won't do any harm ...
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Thanks Gyvate, I asked about the bottom plate as Raffaello has the bottom plate painted Matt Black on his link.
I somehow thought it may be to absorb the ground radiated heat to allow it to be dissipated by the white louvres, or some form of convection something like a zebra's stripes.
I have done plenty of searching but can not find an explanation.