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Weather Station Hardware => Other Weather Station Hardware => Topic started by: AdkManUpstateNY on June 05, 2019, 01:47:36 AM
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Hi. I am planning to build my own solar radiation shield for the digital temperature and humidity sensor unit to my La Crosse Technology S84060 Professional Weather Station. I'm waiting for the arrival of some white Melamine plastic rounded square salad bowls I purchased online. They are 9" in diameter and 3.5" tall. I ordered four of them. I plan to leave a generous 3" gap for air flow and ventilation between each bowl. 1/2" of their 3.5" height will be the overlap distance between the bottom and the top of the stacked bowls. I have found a few places on the internet where some folks have described "somewhat" how they constructed theirs.
My question: Should the very bottom of the solar radiation shield be left open for better upwards air flow and ventilation? Or closed by leaving the bottom bowl with no drilled hole in the center? *I intend on installing a fine, plastic mesh insect screen completely around the interior to keep the bugs/bees/insects out. The digital sensor (LTV-TH3 Sensor) measures 5.73" tall...1.97" wide...and 0.75" deep (or thick) at its deepest point.
Here's a crude graphic I drew up using Microsoft Paint. **Not to scale. Melamine salad bowls are not rounded on the corners.
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The temperature/humidity sensor unit.
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The Melamine bowl (x4)
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Others will weigh in with varying opinions. I have a higher-end Onset HOBO weather station, with their passive RS1 Solar Radiation Shield. From what I've read and seen, shields are generally only open on the bottom if they are fan-aspirated. Many people on this forum favor fan-aspirated shields that have open-bottoms, but some have expressed worries about rising heat coming in that bottom opening from whatever surface is below.
The Onset RS1 is a large, solid unit that is sold separately for $79. Like many better shields, it has both fully closed and open-center plates, and a metal plate at or near the top to handle the most direct rays of the sun. Mine is now 10 years old and still looks brand new; some plastics will deteriorate badly in the sun and weather. I mention it only for comparison purposes. It's worth looking at their page for the RS1 at https://www.onsetcomp.com/products/mounting/rs1
Under the "documentation tab, you can read their installation guide, which contains thorough descriptions of parts and many drawings that may give you some ideas. Make sure you can easily disassemble your shield to keep it cleaned out inside.
Rich K.
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Hard to beat these. Rated as one of the best naturally aspirated shields by WMO in field test conducted a few years back. Scaled instruments sells them cheaper than retail around $67.
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I made a shield from 5 plastic bowls from the dollar store. Cost me five bucks all in. I used threaded rod and leftover plastic tube for the spacers.
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Many people on this forum favor fan-aspirated shields that have open-bottoms, but some have expressed worries about rising heat coming in that bottom opening from whatever surface is below.
Exactly why proper sitting is crucial to any wx station, PWS or otherwise. A closed vs open bottom will suck (pun intended) equally as bad sitting over asphalt.
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Thanks to those for their input [tup]
But I still don't know which is preferred :???: I don't plan on it being fan aspirated. If not, which is better... an open or closed bottom?
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Experiment. They are just salad bowls, right? Put holes in one and not the other.
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Experiment. They are just salad bowls, right? Put holes in one and not the other.
Yes, they are salad bowls. But they are not cheap, flimsy plastic ones. And I only ordered four of them on account of their size: 9" x 9" (rounded square bowls) that are 3.5" tall. I'm thinking the finished radiation shield will be 12" tall. The temperature/humidity sensor it will house is just 5.73" tall. Of course the top bowl will be solid and without a hole (lol). The next two will have holes cut out in their center to accommodate the sensor. It is the bottom bowl I am unsure of. Keep it solid or cut a hole in the center to create an open bottom? They are made of Melamine plastic. Melamine is rated to have a very good UV resistance. And medium to excellent heat resistance. It is very durable and very hard plastic.
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In my HM shield. I used a hole saw to drill about 4" holes in all but the top bowl. Gotta find that picture...
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In my HM shield. I used a hole saw to drill about 4" holes in all but the top bowl. Gotta find that picture...
I won't know the diameter of the holes in mine until the bowls arrive in the mail and I get to see what I'll have to work with. I look forward to seeing it if you can find it Bushman :-) [tup]
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The bowls finally arrived in today's mail. These were advertised as being 9" rounded square bowls, but measure 8 7/8" in diameter. They were also advertised as being 3 1/2" in height, but only measure 3" in height. I got a great start on its construction late this evening. The only things left to do are cutting out "squares" in either two or the final three bowls to accommodate the digital temperature and humidity sensor unit. And I still need to finish up the mounting bracket(s) on the top...and cutting a few more "spacers" needed. Here's some pics. of the rough dry fit. I added in the water bottle for size reference. It should top out at around 12" tall with the mounting bracket hardware included on the top :grin: As you can see, I went with four threaded rods 1/4" in diameter and 12" long rather than the usual three threaded rods as most seem to use when fabricating these. I think four rods in a square configuration is more study and stable than three rods in a triangular configuration. I hope to finish it within the next day or two. I will post more pics along the way when I can.
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I personally would reduce the length of the spacers. In theory you should not see the sensor inside the housing from any angle (although you have not installed it yet). In this way you avoid the reflected radiation, or so it is my understanding.
Those bowls look class though. Can I ask how much they were?
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As I think I suggested earlier, if it will not be fan aspirated, I would leave the bottom bowl solid with no hole cut into it. That's the way my Onset HOBO "factory" one is. Hope it has been a fun project for you...
Rich K.
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I personally would reduce the length of the spacers. In theory you should not see the sensor inside the housing from any angle (although you have not installed it yet). In this way you avoid the reflected radiation, or so it is my understanding.
Those bowls look class though. Can I ask how much they were?
These bowls have a very glossy/high shine finish. I believe they will do a fine job at reflecting the Sun's rays rather than absorbing them. These bowls were listed at $8.99 each marked down to $3.00 a piece at a website called Hollar.com
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As I think I suggested earlier, if it will not be fan aspirated, I would leave the bottom bowl solid with no hole cut into it. That's the way my Onset HOBO "factory" one is. Hope it has been a fun project for you...
Rich K.
It was a fun project until it came time to cut the square openings in these Melamine hard plastic bowls. I decided to only leave the top bowl untouched. I drilled a series of holes to make room for my sabre saw blade, and cutting out these square holes was a chore...at times the plastic shattered :roll:
To suspend the temperature and humidity sensor unit inside, I simply used plastic coated "twist-tie wires" you get on loaves of bread. I am NOT happy with the strength of the two white shelf brackets I purchased from a hardware store. They bend too easily. I plan on coming up with a more sturdy mounting bracket in time. This solar radiation shield is very sturdy and built strong!!
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More pics.
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Since I only rent the upstairs apartment in this building, and the lawn space being quite narrow, I am limited in where I can site this solar radiation shield. I don't dare attempt to sink a wooden post in the middle of the lawn. My older AcuRite 00589 outdoor sensor was mounted using a satellite dish mounting arm close to three years ago. I had no other choice but to mount it to a tree. That sensor has performed remarkably well given its close proximity to the road and for being underneath a tree. So I will soon see how this solar radiation shield for the temperature and humidity sensor to my La Crosse weather station performs mounted here. It sits 7' above the lawn. The AcuRite 00589 pictured sits at 8'.
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Under a tree is not the best place, but it isn't a really large tree, and it is a good distance from any buildings. The roadway will likely affect things, especially if a light breeze is off of it in it's direction.
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Under a tree is not the best place, but it isn't a really large tree, and it is a good distance from any buildings. The roadway will likely affect things, especially if a light breeze is off of it in it's direction.
I really don't understand why everyone says under a tree is not a good place. In the late spring, during the summer, and up until the foliage falls off trees in the autumn, they provide protection from the sun's rays and provide a much needed shaded area. And mine is far from any building..probably a good 200' + away from my apartment building. It's also not up close against the tree, and I really don't see where humidity would be any worse where I have it as compared to over the open lawn.
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Under a tree is not the best place, but it isn't a really large tree, and it is a good distance from any buildings. The roadway will likely affect things, especially if a light breeze is off of it in it's direction.
I really don't understand why everyone says under a tree is not a good place.
I'm not agreeing or disagreeing with this article as I have absolutely no way of attempting it, but know a quality shield is designed for complete, unabated sun exposure.
https://weatherstationexpert.com/things-to-keep-in-mind-when-installing-a-weather-station/
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Under a tree is not the best place, but it isn't a really large tree, and it is a good distance from any buildings. The roadway will likely affect things, especially if a light breeze is off of it in it's direction.
I really don't understand why everyone says under a tree is not a good place.
I'm not agreeing or disagreeing with this article as I have absolutely no way of attempting it, but know a quality shield is designed for complete, unabated sun exposure.
https://weatherstationexpert.com/things-to-keep-in-mind-when-installing-a-weather-station/
Your link above makes sense as it states: "Never install your weather station under a tree or overhang, as this can make the rainfall data measured by your system incorrect."
This radiation shield I built is for the temperature and humidity sensor only. The rain collector in located 29' off the ground and is mounted above and off to the side of the roof and nothing around it for 100-150' or more. And I did not purposely site it beneath the tree because I don't have confidence in its ability to perform adequately in full sun exposure. The other day I left it outside in the blazing sun to see how much the melamine bowls heated up to direct exposure to the sun's rays and it was remarkably quite cool to the touch when I removed it from the sunlight. I mounted it where I did because space is limited and I have no better options. My AcuRite 00386SDI weather station multi sensor has been mounted there for over 2.5 yrs. now and has performed flawlessly.
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Under a tree is not the best place, but it isn't a really large tree, and it is a good distance from any buildings. The roadway will likely affect things, especially if a light breeze is off of it in it's direction.
I really don't understand why everyone says under a tree is not a good place.
I'm not agreeing or disagreeing with this article as I have absolutely no way of attempting it, but know a quality shield is designed for complete, unabated sun exposure.
https://weatherstationexpert.com/things-to-keep-in-mind-when-installing-a-weather-station/
Your link above makes sense as it states: "Never install your weather station under a tree or overhang, as this can make the rainfall data measured by your system incorrect."
This radiation shield I built is for the temperature and humidity sensor only.
I didn't post this link about rainfall, that's hopefully the obvious part. We're taking about radiation shields, right? If you'd read down further, this was stated:
Humidity sensors must be located at least 50 ft away from any plant, tree or water body, as they can affect the humidity measurements. Even if there is any of it, the humidity sensor must be at least 50 ft away from it.
Like I said, no experience myself, but makes sense, especially after a rain.
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Under a tree is not the best place, but it isn't a really large tree, and it is a good distance from any buildings. The roadway will likely affect things, especially if a light breeze is off of it in it's direction.
I really don't understand why everyone says under a tree is not a good place.
I'm not agreeing or disagreeing with this article as I have absolutely no way of attempting it, but know a quality shield is designed for complete, unabated sun exposure.
https://weatherstationexpert.com/things-to-keep-in-mind-when-installing-a-weather-station/
Your link above makes sense as it states: "Never install your weather station under a tree or overhang, as this can make the rainfall data measured by your system incorrect."
This radiation shield I built is for the temperature and humidity sensor only.
I didn't post this link about rainfall, that's hopefully the obvious part. We're taking about radiation shields, right? If you'd read down further, this was stated:
Humidity sensors must be located at least 50 ft away from any plant, tree or water body, as they can affect the humidity measurements. Even if there is any of it, the humidity sensor must be at least 50 ft away from it.
Like I said, no experience myself, but makes sense, especially after a rain.
I read the entire article. And as I stated I do not own the land on which I live. I rent the upstairs apartment. The lawn is not all that big. It's much longer than it is wide. The lawn is bordered by a creek on one side. Just below the brush and bushes you see in this pic. and to the left. And it's bordered by a paved street on the other side. I do not dare dig up the lawn which again is not mine and sink a wooden post smack dab in its narrow center. I don't mow the lawn and I don't think the caretaker who does wants to mow around a wood post. I sited it as best as I could and what I have to work with. And the article makes a pretty silly statement by saying 50' away from any plant(what a joke!) tree, or body of water. Mounting a solar radiation shield at least 5 feet above grass violates the 50' rule in my honest opinion. Grass is a plant/vegetation!!! It holds moisture too!
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You wondered about why trees and sensors potentially do not belong together, I supplied the article, be it right, wrong, or indifferent. There are very few PWS owners who "have it all". Considering your situation, you're lucky to have what you have.
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You wondered about why trees and sensors potentially do not belong together, I supplied the article, be it right, wrong, or indifferent. There are very few PWS owners who "have it all". Considering your situation, you're lucky to have what you have.
I didn't wonder anything. You stepped in and supplied an article which I think contradicts itself. When pertaining to humidity and moisture from plants and trees as things that should be avoided by at least a distance of 50', the author then states make sure your humidity sensor is mounted at least 5' above grass. Last I knew grass is a plant/vegetation which takes on moisture... and a whole lot of it. I end my discussion with you here and now.
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[tup]
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[tup]
[tup]
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The idea behind official standards for mounting is to get objective data uninfluenced by local geographic variables.
Just realize that your temp data will only be accurate for what is happening under those trees regardless of how effective the radiation shield performs.
Too bad you can't set up the temp sensor with shield somewhere in full sun and another one under the trees to compare. That would be an interesting study.
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The tree will cause the thermometer to read a little low in the day, and warm at night. Also the humidity will be higher under a tree all the time compared to an open skyline, which is where you are technically supposed to mount an air sensor. We all do the best we can, and if this is what you have, then you do what you have to. It is definitely better than against the building.
The shield looks like a really good build to me. I made one myself also, but the plastic was brittle like yours, and the last hurricane beat it up some, but I still use it.
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The tree will cause the thermometer to read a little low in the day, and warm at night. Also the humidity will be higher under a tree all the time compared to an open skyline, which is where you are technically supposed to mount an air sensor. We all do the best we can, and if this is what you have, then you do what you have to. It is definitely better than against the building.
The shield looks like a really good build to me. I made one myself also, but the plastic was brittle like yours, and the last hurricane beat it up some, but I still use it.
Thank you. I am happy with the build. It's very tough plastic...not brittle at all. But it WAS difficult to cut the square openings out with the sabre saw. The temps it's recording look pretty much spot on to me. The humidity readings have been too when compared to neighboring weather stations on WU...so I'm not really seeing a difference. I didn't want to mount it on the side of the buidling or even close to it. There is a NYS Mesonet weather station located just 2.9 miles from me. It sits on a higher elevation and was built in a wide open field...it's where I launch all my model rockets BTW ;) It's elevation is at 1,089 feet. Mine is at 843 feet. I use it all the time to compare my readings and my weather station is very close to this one most of the time on readings.
Here's a link to the weather station site: http://www.nysmesonet.org/mesonow#?stid=CHES
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Glad you found someone who's word you can trust.
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Glad you found someone who's word you can trust.
Please read my above post ;)
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Glad you found someone who's word you can trust.
Please read my above post ;)
Ummm, what??
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Glad you found someone who's word you can trust.
Please read my above post ;)
Ummm, what??
From my post above:
The temps it's recording look pretty much spot on to me. The humidity readings have been too when compared to neighboring weather stations on WU...so I'm not really seeing a difference. I didn't want to mount it on the side of the buidling or even close to it. There is a NYS Mesonet weather station located just 2.9 miles from me. It sits on a higher elevation and was built in a wide open field...it's where I launch all my model rockets BTW ;) It's elevation is at 1,089 feet. Mine is at 843 feet. I use it all the time to compare my readings and my weather station is very close to this one most of the time on readings.