Author Topic: I painted my Acurite 5 in 1, have you?  (Read 15039 times)

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Offline DoctorKnow

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I painted my Acurite 5 in 1, have you?
« on: August 14, 2014, 01:02:24 PM »
I thought we could continue our discussion and sharing results from those of us who have actually painted the bottom of their 5 in 1. I painted my whole unit, except for the battery cover and the screen for the temp and humidity sensor. So far I have been very pleased by the results, as I see no more crazy spikes as the sun moves from one side to the other. Others also have painted and have found improved readings. The issue appears to be the dark color of the bottom of the assembly.

I would like to ask if we could please just discuss the paint, and those comparisons, and not comparing a new 5 in 1 to an old one without adding any paint. It really doesn't add anything because we all know that two unpainted units will give the same results. This also does not have to do with spiders and changing weather conditions.

SOme of us thought that the solar panels were the real problem, but we are finding now that those may only have been a slight issue, and the main issue being the bottom.

If anyone would like to try and paint the top wind assembly cups and spike to see if the chimeney affect can make a difference, that would be welcome too. 8-)

Offline miraculon

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Re: I painted my Acurite 5 in 1, have you?
« Reply #1 on: August 14, 2014, 04:22:51 PM »
Although I don't have one, I found the Acurite 5-in-1 to be an interesting station. I was also puzzled about the dark bottom. The Davis Vantage Vue also has a black bottom.

I wonder what the reason is for the darker bottom section. Absorb sunlight to thaw a frozen wind vane? Stealth effect looking up at it at night?

DoctorKnow, did you use that special plastic-compatible spray paint or primer? It seems that that would be necessary otherwise it might peel off at some point. I have used the plastic-compatible paint on a homebrew project (thermal siphon) and it held up well. (Home Depot, but I don't remember the brand. Might have been Krylon)

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Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #2 on: August 14, 2014, 04:49:15 PM »
I think with the Davis, the sensors are below the black bottom, in those shields, but not positive.

I don't understand the design with this 5 in 1 with no shields under it. That is one thing that has had me curious since I've had it. I don't feel like enough air moves through there when the fan is off.

I didn't use plastic paint. I went to Lowes and they didn't have any. I should have gone to Home depot. The Rustoleum paint did seem to dry on well.

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #3 on: August 14, 2014, 06:22:13 PM »
Although I don't have one, I found the Acurite 5-in-1 to be an interesting station. I was also puzzled about the dark bottom. The Davis Vantage Vue also has a black bottom.

Some pictures will help.  These are from my "parts and test" 5n1.  It's in clean condition as you would get it out-of-the-box.


Here's the side view.  My thumb is near the screen of the wind tunnel.  The bottom section is darker than the top, but not by much.  You be the judge.




This is looking at the bottom section after the white top is removed.  Note the black interior shield.  It covers the electronics, and also helps form a sealed wind tunnel in which the temp/humidity sensor sits.




Here's another view of the bottom section and black shield.  Note the temp/humidity sensor board down in the throat of the wind tunnel.  Also note the number of plastic walls and dead spaces solar radiation would have to overcome to get to the time/humidity sensor from the side.




Here's a view with the black shield removed.  Note the base of the windtunnel throat is built up around the sensor.  That seals the sides of the wind tunnel and acts as another block to solar radiation from the side.  Again, note the number of barriers between the side and the sensor.







Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #4 on: August 14, 2014, 07:13:01 PM »
In the last picture, at the top of the image is a "probe". Isn't that the temperature sensor? If not, what is it? I could not figure that out when I had mine apart.

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #5 on: August 14, 2014, 07:33:53 PM »
In the last picture, at the top of the image is a "probe". Isn't that the temperature sensor? If not, what is it? I could not figure that out when I had mine apart.

That's not a probe.  It's a crystal.

The temp/humidity sensor is in the throat of the wind tunnel.

Here's the temp/humidity sensor assembly pulled out of the throat.



Here's a closer view.


Still not convinced?  Here's the SHT21 data sheet:  http://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/Humidity/Sensirion_Humidity_SHT21_Datasheet_V4.pdf
« Last Edit: August 14, 2014, 08:06:34 PM by nincehelser »

Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #6 on: August 15, 2014, 10:06:32 AM »
I was just curious what the probe does...

Offline Beaudog

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Re: I painted my Acurite 5 in 1, have you?
« Reply #7 on: August 15, 2014, 11:27:50 AM »
Nice pictures George.     Is that the transmitter board  with the spring looking antenna on it>

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #8 on: August 15, 2014, 12:00:29 PM »
I was just curious what the probe does...

Again, what you're referring to is a crystal, not a probe.  It's part of an oscillating circuit. 

http://en.wikipedia.org/wiki/Crystal_oscillator

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #9 on: August 15, 2014, 12:02:16 PM »
Nice pictures George.     Is that the transmitter board  with the spring looking antenna on it>

Yep!

Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #10 on: August 15, 2014, 12:40:00 PM »
George, have you given any thought to painting your 5 in 1 yet? Mine is sure running cooler now. I am even cooler than the other sites sometimes, which is what should happen. I live in an area blanketed by old tall trees, and near water. I should not have seen such a rapid increase and decrease in temps when the sun goes up and down.

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #11 on: August 15, 2014, 01:33:28 PM »
George, have you given any thought to painting your 5 in 1 yet? Mine is sure running cooler now. I am even cooler than the other sites sometimes, which is what should happen. I live in an area blanketed by old tall trees, and near water. I should not have seen such a rapid increase and decrease in temps when the sun goes up and down.

No.  As I have said before, my equipment is already reading accurately as confirmed by controlled testing and comparison with other sensors.

If I were to paint it and I started getting readings cooler than my surroundings, I'd suspect I contaminated the sensor (see the warnings in the spec sheet). 




Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #12 on: August 15, 2014, 01:48:34 PM »
The part that I don't think you understand about the paint is it keeps the unit stable when the fan is not running. That is when people are getting errors and warmer readings than their surroundings. When the fan is on, that keeps the air mixed, and you get mainly accurate temps and wet bulbs. However, when the sun is rising and setting, the dark color absorbs the sunshine rays, and it fouls up the sensor, and you run up to 10 degrees high. It's been proven over and over and over and over.

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #13 on: August 15, 2014, 02:47:50 PM »
The part that I don't think you understand about the paint is it keeps the unit stable when the fan is not running. That is when people are getting errors and warmer readings than their surroundings. When the fan is on, that keeps the air mixed, and you get mainly accurate temps and wet bulbs. However, when the sun is rising and setting, the dark color absorbs the sunshine rays, and it fouls up the sensor, and you run up to 10 degrees high. It's been proven over and over and over and over.

I understand how fan aspiration works.  That's why it's important to keep the aspirating fan running properly on the 5n1 until the heat load goes down.  That has been "proven over and over and over and over".   

My fan is working fine, and that's why I don't have problems.  I also don't let mold grow on my sensor.  I clean it occasionally....blow the dust off the solar panel, check alignment to true (not magnetic) north, lubricate a bit with silicone spray, remove spiders, etc.... but you didn't want anyone talking about those things, remember?

If "painting the bottom" was a silver-bullet solution, don't you think someone would have stumbled on that a long time ago?  You're not exactly the first person to have that idea.  Others have also tried things like white tape, white plastic skirts, and other contraptions.  They haven't proven themselves effective. 

However, what always works is keeping the aspiration fan running properly, even if that means adding extra panels or other auxiliary power.

To sum up, if your fan isn't running, maybe it should be.


« Last Edit: August 15, 2014, 02:51:02 PM by nincehelser »

Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #14 on: August 15, 2014, 03:41:16 PM »
The part that I don't think you understand about the paint is it keeps the unit stable when the fan is not running. That is when people are getting errors and warmer readings than their surroundings. When the fan is on, that keeps the air mixed, and you get mainly accurate temps and wet bulbs. However, when the sun is rising and setting, the dark color absorbs the sunshine rays, and it fouls up the sensor, and you run up to 10 degrees high. It's been proven over and over and over and over.

I understand how fan aspiration works.  That's why it's important to keep the aspirating fan running properly on the 5n1 until the heat load goes down.  That has been "proven over and over and over and over".   

My fan is working fine, and that's why I don't have problems.  I also don't let mold grow on my sensor.  I clean it occasionally....blow the dust off the solar panel, check alignment to true (not magnetic) north, lubricate a bit with silicone spray, remove spiders, etc.... but you didn't want anyone talking about those things, remember?

If "painting the bottom" was a silver-bullet solution, don't you think someone would have stumbled on that a long time ago?  You're not exactly the first person to have that idea.  Others have also tried things like white tape, white plastic skirts, and other contraptions.  They haven't proven themselves effective. 

However, what always works is keeping the aspiration fan running properly, even if that means adding extra panels or other auxiliary power.

To sum up, if your fan isn't running, maybe it should be.

If my fan should be running in the cloudy or dark weather, then the 5 in 1 should have been built for that to be possible. It was not, so I am covering up the dark design with white paint to keep the bottom from becoming an oven, and fouling up my data. I did add a solar panel, but the bottom becomes so hot, that even the fan going full speed cannot cool it enough. That has been proven over and over and over and over.

Can you show me where anyone has mentioned "paint" besides us in the solar panel thread?
« Last Edit: August 15, 2014, 03:42:53 PM by DoctorKnow »

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #15 on: August 15, 2014, 05:29:11 PM »
If my fan should be running in the cloudy or dark weather, then the 5 in 1 should have been built for that to be possible. It was not, so I am covering up the dark design with white paint to keep the bottom from becoming an oven, and fouling up my data. I did add a solar panel, but the bottom becomes so hot, that even the fan going full speed cannot cool it enough. That has been proven over and over and over and over.

Can you show me where anyone has mentioned "paint" besides us in the solar panel thread?

It is possible for it to work properly.  There are a lot of us that aren't having a problem.

The bottom of your unit is such an "oven" that even a full-speed fan can't cool it?  Seriously?   :roll:

I hope the information I've provided is helpful to others.  At least some will get a better understanding of the 5n1's internals.

I'm bowing out for now... I've got a Kaminski filter that needs adjusting.   
 

Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #16 on: August 15, 2014, 08:35:02 PM »
Sir, with all due respect,

I check acurite stations all over wunder, and I see stations running high all over the place. Some as much as 10 degrees!  I also see fine offset models running that high... You cannot have poor siting on top of a housing that is not designed for sunlight in the sun and not have bad data being fed. When you install a station and put out the data, you are expected to follow a standard and control the quality of that data so that we aren't getting this global warming message out there when it isn't happening. People see that stuff and jump all over this climate change agenda. It's a hoax, and being helped by poorly sited weather instruments, and faulty equipment.

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #17 on: August 15, 2014, 09:17:22 PM »
Sir, with all due respect,

I check acurite stations all over wunder, and I see stations running high all over the place....

 :roll:

Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #18 on: August 16, 2014, 03:06:15 PM »
What KIND of paint are you planning on using?

Some paints that you'd *think* would be good reflectors (white) aren't...they're actually thermal *collectors* due to the chemical-content of the paint's reaction to the infrared (heat) component of sunlight. Basically, they end up absorbing HEAT instead of reflecting it away like you want.

All I can say is that the Rustoleum Glossy White Enamel is what I used, and it made my station much more in line with the real temperature. I was going to use a Flat paint, but because of what Nincehelser recommended, I went with Glossy. Then he comes after me with skepticism, and such, and even says I called him a liar, which I did NOT. I said he was trying to make me out to be a liar.

I am not lying. The paint works. Just do it. :-)

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #19 on: August 16, 2014, 04:03:36 PM »
What KIND of paint are you planning on using?

Some paints that you'd *think* would be good reflectors (white) aren't...they're actually thermal *collectors* due to the chemical-content of the paint's reaction to the infrared (heat) component of sunlight. Basically, they end up absorbing HEAT instead of reflecting it away like you want.

All I can say is that the Rustoleum Glossy White Enamel is what I used, and it made my station much more in line with the real temperature. I was going to use a Flat paint, but because of what Nincehelser recommended, I went with Glossy. Then he comes after me with skepticism, and such, and even says I called him a liar, which I did NOT. I said he was trying to make me out to be a liar.

I am not lying. The paint works. Just do it. :-)

Wow.  So why didn't you clarify yourself a long time ago?

I wrote as an aside: "FYI - I recently finished running two 5n1 sensors side-by-side, one old and yellowed, the other pristine glossy white.  They were both accurate within 1F degree of each other and seemed reasonable compared to other regional stations.  Your mileage may vary, of course.  Details are on Acurite's site.""

You responded: "Obviously you are trying to prove me wrong, and a liar."

Which to me was an unexpected and outrageous response I didn't deserve.

The comma makes a huge difference in meaning.  In any case, I wasn't trying to "prove you wrong", I just related my experience.  I think I've made that pretty clear.  I still don't understand why that should set you off.

Offline DaleReid

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Re: I painted my Acurite 5 in 1, have you?
« Reply #20 on: August 16, 2014, 04:06:59 PM »
I'm not sure if it is generally available, or where to get it, or what it would cost, but while at Kitt Peak near (well, 65 miles near) Tucson, AZ, we toured the solar observatory.  The thing that looks like a '7' lying on its side.

The whole thing is white or a greyish white, having been painted with something to reflect the sun and keep the open scope at near ambient temperatures. 

I'm sure some grad student got a doctoral thesis out of developing the paint and monitoring.  While it was a quite hot day we were there, getting into the base of the building to see the mirrors and the projected image of the sun's disk was noticeably cooler than the other open buildings we ventured into.  So I would guess there is something about painting black things a reflective color.

But put your thermometer over a dark shingle roof and it's going to be exposed to much warmer air than what a NWS compliant station location will read.

http://nsokp.nso.edu/info

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Offline DaleReid

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Re: I painted my Acurite 5 in 1, have you?
« Reply #21 on: August 16, 2014, 04:19:43 PM »
The paint is titanium dioxide, and in addition to the paint a huge thermal mass of concrete and circulating gylcol solution is used along the light path into the mountain.

Interesting discussion in the associated history of the telescope paper, at

http://nsokp.nso.edu/sites/nsokp.nso.edu/files/files/history/McM-P_History.pdf

To show you how much they worried about heating, the history document says the even calculated how much the air temperature would be increased by the wind eddy currents flowing past the wind breaks surrounding the heliostat.

In case you don't want to read the whole thing, the max heating worked out to be less than 0.05C. 

They ignored it.

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Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #22 on: August 16, 2014, 04:33:20 PM »
I'm not sure if it is generally available, or where to get it, or what it would cost, but while at Kitt Peak near (well, 65 miles near) Tucson, AZ, we toured the solar observatory.  The thing that looks like a '7' lying on its side.

The whole thing is white or a greyish white, having been painted with something to reflect the sun and keep the open scope at near ambient temperatures. 

I'm sure some grad student got a doctoral thesis out of developing the paint and monitoring.  While it was a quite hot day we were there, getting into the base of the building to see the mirrors and the projected image of the sun's disk was noticeably cooler than the other open buildings we ventured into.  So I would guess there is something about painting black things a reflective color.

But put your thermometer over a dark shingle roof and it's going to be exposed to much warmer air than what a NWS compliant station location will read.

http://nsokp.nso.edu/info

True.  If something is black, painting it white can make a big difference.  No doubt about that,  but what's being argued here is painting something "off-white" or "beige" (see the picture near the start).  The 5n1, particularly the bottom, doesn't have external black components like Davis products. 

I'm just trying to clear up any confusion on the color configuration between the two brands.

It's funny you mention the shingles.  Recently some guy got all torqued up on the Acurite support site because he wasn't getting accurate temp readings on his roof-mount.  Someone pointed out the heat coming off the shingles might be an issue, and he angrily countered the instructions only warned against siting over "asphalt and concrete" not shingles and Acurite should update their instructions.

There's just no pleasing some people.

Offline DoctorKnow

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Re: I painted my Acurite 5 in 1, have you?
« Reply #23 on: August 16, 2014, 04:39:33 PM »
The color is dark enough (grey) that it absorbs enough sun to raise the temp on the chip which is located inside the gray bottom of the 5 in 1 to cause a real mess for about 2 hours in the morning, and then 2 hours in the evening as the sun sets.

Since we are off topic again... I will add too that...

Another thing that is really bothering me about acurite and their stupid bridge is they will not let me share with PWS and CWOP. I will not go the meteobridge way. I will do ambient. The reason I bought the dumb bridge was so I could share... 15 minute updates is absurd. They should let YOU choose how often to update. 15 minutes or even an hour at night is fine, but during the day, I want it live.
« Last Edit: August 16, 2014, 04:41:55 PM by DoctorKnow »

Offline nincehelser

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Re: I painted my Acurite 5 in 1, have you?
« Reply #24 on: August 16, 2014, 05:06:13 PM »
The color is dark enough (grey) that it absorbs enough sun to raise the temp on the chip which is located inside the gray bottom of the 5 in 1 to cause a real mess for about 2 hours in the morning, and then 2 hours in the evening as the sun sets.

Since we are off topic again... I will add too that...

Another thing that is really bothering me about acurite and their stupid bridge is they will not let me share with PWS and CWOP. I will not go the meteobridge way. I will do ambient. The reason I bought the dumb bridge was so I could share...

Others aren't having that problem because their fan is running properly, but that field has already been plowed.

There are many of us already sharing data from the Acurite bridge with various methods.  I'm sorry none of those was acceptable to you.  I'm not sure calling the bridge "stupid" and "dumb" is really warranted, though.  It just is what it is, and Acurite has left it open enough that sufficiently interested folks can read the data and do with it what they will.