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Weather Station Hardware => AcuRite Weather Stations => Topic started by: txbayou on October 10, 2018, 09:14:41 PM
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The UV reading on my Atlas is rarely above 1 during daylight hours. I’m trying to figure out if this is a defect, or a correct reading based on my Atlas getting at most 2-3 hours of direct sunlight in its current location, in mid October. The light intensity function seems to work, and shows a short period of peak light, which then drops over the afternoon. In the summertime, there would be direct sunlight on the sensor for a far longer time.
Other PWS readings in the area from Ambient PWS’s show high UV readings of 5-7 over several hours, which corresponds to the NWS forecasts of the UV highs for the area.
Do UV sensors need longer periods of sustained sunlight to give accurate readings, or is the one in my Atlas defective? How long does the UV sensor have to be in direct sunlight before it will go above 1 or 2?
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The UV reading on my Atlas is rarely above 1 during daylight hours. I’m trying to figure out if this is a defect, or a correct reading based on my Atlas getting at most 2-3 hours of direct sunlight in its current location, in mid October. The light intensity function seems to work, and shows a short period of peak light, which then drops over the afternoon. In the summertime, there would be direct sunlight on the sensor for a far longer time.
Other PWS readings in the area from Ambient PWS’s show high UV readings of 5-7 over several hours, which corresponds to the NWS forecasts of the UV highs for the area.
Do UV sensors need longer periods of sustained sunlight to give accurate readings, or is the one in my Atlas defective? How long does the UV sensor have to be in direct sunlight before it will go above 1 or 2?
I live in Pennsylvania and my uv has not gone above a reading of 3 since I installed the Atlas a couple weeks ago. I asked Acurite about this, since the closest station gets up to a 5 or 6 at times. Acurite told me my uv readings are in line with surrounding stations. I checked around myself on WU today and found several nearby Ambient stations that had uv readings with a high ranging from 3 to 9. Are they off or is my Atlas off? Today, the Ambient station up the street from me got up to 4 and I got up to 3. The first screenshot is the Ambient station up the street and the other two screenshots are my uv and light intensity for today. [ You are not allowed to view attachments ] [ You are not allowed to view attachments ] [ You are not allowed to view attachments ]
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I had the same problem with my now returned Atlas; I never got uv readings over 3 in the Arizona sunny desert; my ws2000 that I replaced it with, has had readings up to 8 in the same location..
There are all sorts of issues with this first release of Atlas; just check these forums and the internet and you will see..
I'd return it, if its still returnable, and either try a replacement, or a different brand..
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So, today is the first day my Atlas uv went passed a reading of 3. I hit a 4 today. MyAcurite only recorded a high of 3, but my display recorded a high of 4. So I suppose I hit 4 within the 5 minute update for MyAcurite and is why it is not showing a 4 as well on MyAcurite. This is why I wish the updates for MyAcurite were more frequent because it can be misleading and cause you to think something is inaccurate when it may not be.
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So, today is the first day my Atlas uv went passed a reading of 3. I hit a 4 today. MyAcurite only recorded a high of 3, but my display recorded a high of 4. So I suppose I hit 4 within the 5 minute update for MyAcurite and is why it is not showing a 4 as well on MyAcurite. This is why I wish the updates for MyAcurite were more frequent because it can be misleading and cause you to think something is inaccurate when it may not be.
I agree 5 minutes is way to long weather can change many times in that time frame I don't like it, Heck the old system update was 15 minutes! that was ridicules #-o
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ambientweather.net gives you 1 minute updates (also sends to PWSweather.com in 1 minute uploads). Just saying in case you were looking to return and wanted something else. That doesn't necessarily make it better but it might have a factor as you build your personal pros and cons list.
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So, today is the first day my Atlas uv went passed a reading of 3. I hit a 4 today. MyAcurite only recorded a high of 3, but my display recorded a high of 4. So I suppose I hit 4 within the 5 minute update for MyAcurite and is why it is not showing a 4 as well on MyAcurite. This is why I wish the updates for MyAcurite were more frequent because it can be misleading and cause you to think something is inaccurate when it may not be.
I agree 5 minutes is way to long weather can change many times in that time frame I don't like it, Heck the old system update was 15 minutes! that was ridicules #-o
Faster myAcurite updates aren't out-of-the-question, but some folks get freaked out when the subject of tiered subscriptions comes up.
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So, today is the first day my Atlas uv went passed a reading of 3. I hit a 4 today. MyAcurite only recorded a high of 3, but my display recorded a high of 4. So I suppose I hit 4 within the 5 minute update for MyAcurite and is why it is not showing a 4 as well on MyAcurite. This is why I wish the updates for MyAcurite were more frequent because it can be misleading and cause you to think something is inaccurate when it may not be.
I agree 5 minutes is way to long weather can change many times in that time frame I don't like it, Heck the old system update was 15 minutes! that was ridicules #-o
Faster myAcurite updates aren't out-of-the-question, but some folks get freaked out when the subject of tiered subscriptions comes up.
Would be nice! :grin:
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For what it’s worth, I’m in Pennsylvania and have 9.5kw of solar panels on the roof. Power production this summer has been very poor. Here are screenshots of the UV and Light intensity logs from the Atlas, as well as the output of my solar panels for the same period.
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For comparison, here is what a good cloudless day looks like. [ You are not allowed to view attachments ]
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For what it’s worth, I’m in Pennsylvania and have 9.5kw of solar panels on the roof. Power production this summer has been very poor. Here are screenshots of the UV and Light intensity logs from the Atlas, as well as the output of my solar panels for the same period.
Thanks for posting the screenshots. My UV was flatline with only a few small blips no matter how much direct sun there was. I'm convinced it was broken.
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Frost crystals on the solar lenses?
Cold morning today, a low of 4F degrees. This morning at 7:30 AM-ish I notice that my UV reading was 4, should be zero. I’m speculating that frost crystals on the solar lenses are affecting my UV readings. As the sun continued to rise the UV readings began dropping as I’m speculating that the frost crystals were melting and disappearing. At 8:30 AM the UV readings are fine and back to what they should be. I haven’t noticed any problems on other mornings.
Could the frost crystals be the cause of my bogus early morning UV readings?
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This is interesting.
My THIRD Atlas in one month, I feel, has the failed UV reporting. The third unit fixed the lightning issue.
My first Atlas reported fine.
My second Atlas reported only up to two.
My third Atlas seems to be only reporting up to three.
Here are comparisons from another station I have close by on the same day:
(https://7556552.dotster.com/photos/Screen_Shot_2018-11-13_at_10.18.03_AM.png)
Atlas:
(https://7556552.dotster.com/photos/Screen_Shot_2018-11-13_at_10.19.32_AM.png)
So now what…I guess I will need my FOURTH Atlas?
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could the 4th time be the charm????
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This is interesting.
My THIRD Atlas in one month, I feel, has the failed UV reporting. The third unit fixed the lightning issue.
My first Atlas reported fine.
My second Atlas reported only up to two.
My third Atlas seems to be only reporting up to three.
Here are comparisons from another station I have close by on the same day:
So now what…I guess I will need my FOURTH Atlas?
What are you comparing your readings to?
I've recently been comparing my Atlas readings to this UV forecast page. The results seem reasonable.
https://www.epa.gov/sunsafety/uv-index-1#day1
I'm getting something wildly different on my WeatherFlow SKY, though. While my Atlas was reading "3" (reasonable as per forecast for Central Texas), my WeatherFlow was nearly "8". My WeatherFlow AIR is being replaced due to bad lightning detection. I hope my SKY isn't bad, too.
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This is interesting.
My THIRD Atlas in one month, I feel, has the failed UV reporting. The third unit fixed the lightning issue.
My first Atlas reported fine.
My second Atlas reported only up to two.
My third Atlas seems to be only reporting up to three.
Here are comparisons from another station I have close by on the same day:
So now what…I guess I will need my FOURTH Atlas?
What are you comparing your readings to?
I've recently been comparing my Atlas readings to this UV forecast page. The results seem reasonable.
https://www.epa.gov/sunsafety/uv-index-1#day1
I'm getting something wildly different on my WeatherFlow SKY, though. While my Atlas was reading "3" (reasonable as per forecast for Central Texas), my WeatherFlow was nearly "8". My WeatherFlow AIR is being replaced due to bad lightning detection. I hope my SKY isn't bad, too.
I am comparing it to a Fine Offset clone (image) that is probably 30 feet away from the Atlas. The other weather station I mentioned in other posts is an airport station that reports similar higher UV in my area as well.
It has been a pretty blustery, cloudy the last couple of days here but this is my Fine Offset for the last week:
(https://7556552.dotster.com/photos/Screen_Shot_2018-11-13_at_9.13.40_PM.jpg)
And my Atlas:
(https://7556552.dotster.com/photos/Screen_Shot_2018-11-13_at_9.15.07_PM.jpg)
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The Atlas' UV range is from 0-10 as far as I know and some other stations out there have a wider range than that and may read higher because of the wider range, like 0-15 for example. I live in southeastern PA and the highest UV reading my Atlas recorded since I received it at the beginning of September was a reading of 4. This reading of 4 was on the display, while MyAcurite read a high of 3, since MyAcurite updates are less frequent than the display. This time of year where I live will have lower uv readings compared to the summer because of the angle of the sun. I found out my uv readings are spot on for where I live during this time of year. The stations that read higher, like a reading of 8, could be wrong or their uv range is different. Not sure if I am correct, but it makes sense to me.
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The Atlas' UV range is from 0-10 as far as I know and some other stations out there have a wider range than that and may read higher because of the wider range, like 0-15 for example. I live in southeastern PA and the highest UV reading my Atlas recorded since I received it at the beginning of September was a reading of 4. This reading of 4 was on the display, while MyAcurite read a high of 3, since MyAcurite updates are less frequent than the display. This time of year where I live will have lower uv readings compared to the summer because of the angle of the sun. I found out my uv readings are spot on for where I live during this time of year. The stations that read higher, like a reading of 8, could be wrong or their uv range is different. Not sure if I am correct, but it makes sense to me.
According to the Atlas specifications, it can go up to 15. However, The UV index itself can go much higher. I've heard some complaints that 15 isn't going to be enough for some areas of the world, like Australia.
Here's a general guide to UV exposure. If "8" is a reasonable reading now, I'd hate to be in that same location in the summer.
[ You are not allowed to view attachments ]
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The Atlas' UV range is from 0-10 as far as I know and some other stations out there have a wider range than that and may read higher because of the wider range, like 0-15 for example. I live in southeastern PA and the highest UV reading my Atlas recorded since I received it at the beginning of September was a reading of 4. This reading of 4 was on the display, while MyAcurite read a high of 3, since MyAcurite updates are less frequent than the display. This time of year where I live will have lower uv readings compared to the summer because of the angle of the sun. I found out my uv readings are spot on for where I live during this time of year. The stations that read higher, like a reading of 8, could be wrong or their uv range is different. Not sure if I am correct, but it makes sense to me.
According to the Atlas specifications, it can go up to 15. However, The UV index itself can go much higher. I've heard some complaints that 15 isn't going to be enough for some areas of the world, like Australia.
Here's a general guide to UV exposure. If "8" is a reasonable reading now, I'd hate to be in that same location in the summer.
[ You are not allowed to view attachments ]
I see it now. It does say 15. I think I thought that because I thought someone from Acurite said the uv only went up to 10, but maybe they were saying the reverse and talking about what other brands go up to is only 10. I am pretty sure mine is working fine, since the uv readings are inline with the website you provided as well as weather.com. I consistently have a uv high between 2 and 3 at this time of year so far. I thought something was wrong too, but it's normal for this time of year where I live.
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I should add that my first Atlas did seem to match my other station’s UV reporting...second one was limited to 2 and third Atlas is limited to 3...has never gone above despite intensity.
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Okay...now I replaced the rain bucket for the incorrect UV. Now, my lightning sensor is not showing up.
I have removed the batteries and lightning sensor a number of times (and it clicks in). I have rebooted the Access twice.
This is a different rain bucket.
The lightning sensor does not show up in the managed devices.
The Atlas sensor shows up, just without the lightening sensor...everything else works. Wonder if the lightning fix did something to the rain bucket.
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I'm wondering if Acu-rite uses the same UV sensor component that Oregon Scientific used several years ago? I remember I used to have the WMR200 with UV sensor and initially I had the same problem where the sensor never got above 1 on a sunny summer day. That slowly resolved itself over time. I'm sure they all use the same or similar components.
I'd say give the UV sensor some time to get broken in.
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I've been tracking these complaints carefully, and will continue to do so, but from what I've seen, I think most people are overestimating what UV should actually be in December (depending on where you live, but still...). I'm actually shocked by the variance I've seen from some other units I've tested, and how high they run. If I took their word for it, I would need to be wearing a whole lot more sunscreen right now... in Wisconsin. In December.
Full disclosure, throughout all our testing and revisions and then final units in the field, I have seen a very, very small number of exceptions where the UV sensor seems suspect. But for the vast majority, I think we're just suffering from a crummy case of Early Onset Winter-itis.
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It is now Spring in southeastern Pennsylvania where I live. Since I installed the Atlas back in the fall, the uv has gotten up to a reading of 5 a couple weeks ago. This is the highest it has read. Today, I compared my uv with about 5 ambient stations nearby reporting uv. It is a partly cloudy day around 60°F and my max uv reading today was a 4. The ambient stations nearby ranged from 8-11 as their max uv readings. I checked the EPA site for uv and they forecasted a max uv of 6 for my area today. Either Ambient's uv sensor is inaccurate, the EPA is inaccurate, or Acurite is inaccurate. The Ambient stations seem high and the Atlas seems to be a little low when comparing to what the government's website says. Has anyone else made this observation?
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I live in South Florida and the highest mine has ever reached is a 6 twice. There is definitely something wrong along with the lightning detector that shows daily lightning and the rain gauge that very much under reports. I am quite disappointed with the Atlas so far.
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My third (!) Atlas replacement sensor only went to 2 no matter what. I kept the repaired lightning unit from the third unit and the UV part on the second one to create a fully working unit. Now, my current unit has measured up to 8 in the recent spring days.
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I live in South Florida and the highest mine has ever reached is a 6 twice. There is definitely something wrong along with the lightning detector that shows daily lightning and the rain gauge that very much under reports. I am quite disappointed with the Atlas so far.
Here is a screenshot from the EPA's website for today's forecasted max uv readings. It looks like you should be reading between 9 and 11 for your max today. [ You are not allowed to view attachments ]
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Mine hit 5 today. Seems reasonable. My Beta model never went over 3.
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outside of Phoenix, my Davis UV says its 10 today, as does the US EPA....
I was never able to get an accurate UV number with the Atlas when I had one, and my Ambient station was usually pretty close to what the EPA map said..
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I'll have to take a good look at the sensor. Maybe it is too well shielded with the design, or maybe it needs to be angled?
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I live in South Florida and the highest mine has ever reached is a 6 twice. There is definitely something wrong along with the lightning detector that shows daily lightning and the rain gauge that very much under reports. I am quite disappointed with the Atlas so far.
Here is a screenshot from the EPA's website for today's forecasted max uv readings. It looks like you should be reading between 9 and 11 for your max today. [ You are not allowed to view attachments ]
Based on the map I should have reached a 10. Today the max was 5.
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It appears there is some sort of white piece of shielding under the plastic housing of the UV sensor... I am wondering if it is filtering too much light off the sensor?
Thoughts? I had a fine offset UV sensor, and it was frosted over to filter the light. The white shield on the Atlas is quite solid.
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I was comparing my Fine Offset to the Atlas and when the Atlas was stuck on 2, the Fine matched what others were reporting while the Atlas was on 2. Now that I have the Atlas working, both normally read close to the same.
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If I remember the manufacturer’s docs, it is a place of transclusent Teflon to reduce the intensity of the light
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nincehelser,
Do you think we could try to remove it, or would we break it?
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nincehelser,
Do you think we could try to remove it, or would we break it?
It's removable with your fingertip, but the black circular gasket will come with it. How easy it is to get back in place is another matter... maybe it will sit securely by itself. I'm not sure what problems tacking it back down with CA glue would cause.
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Mine wasn't glued. It was very easy to take out, and put back.
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I would keep it in. It reads way high and really out of wack without it in. There's a reason it's there, but maybe it obstructs the sensor too much with the material they used to filter so it's not so sensitive. I suppose that is the purpose of it. [ You are not allowed to view attachments ] [ You are not allowed to view attachments ]
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I didn't take it out.
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I didn't take it out.
Yea, keep it in then. I still think the Atlas under reports for uv though.
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Here's the application doc for the sensor:
https://www.silabs.com/documents/public/application-notes/AN968-Si1133-UV-Index-Sensor-Electrical-and-Optical-Design-Guide.pdf
From my reading, the "dot" is called the "diffuser", and the plastic cap is referred to as the "overlay".
It does sound like you want the diffuser in place for the best accuracy.
[ You are not allowed to view attachments ]
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Here's the application doc for the sensor:
https://www.silabs.com/documents/public/application-notes/AN968-Si1133-UV-Index-Sensor-Electrical-and-Optical-Design-Guide.pdf
From my reading, the "dot" is called the "diffuser", and the plastic cap is referred to as the "overlay".
It does sound like you want the diffuser in place for the best accuracy.
Good info. I just wonder if the diffuser needs to be improved in some way. If it's in, it seems like it under reports. If it's out, it reads all crazy, which I anticipated it would do. Hmm? Just not sure still if it's accurate enough with the diffuser Acurite uses for it?
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Resurrecting this topic. :)
I got my Atlas, and I am too having issues with UV reporting. While being a little low isn't TOO horrible, what bothers me is that there are times throughout the day where UV will briefly hit ZERO (and then return to bouncing between 1 and 2, when other nearby stations are reporting a solid 3 with an occasional 4.
I live in Phoenix, AZ. It was a completely clear sunny day today. At 11:44am I had a reading of zero briefly (among a few other sporadic zeros throughout the day). No way could there have been a zero UV at that time. Checking back over my daily charts (I've only had the Atlas for about a week), I see some instances from other days where I had a zero reading for UV during the day.
I can understand a bit of a LOW reading, but a ZERO? No way.
So anyway....my reasoning for resurrecting this topic. Since I haven't yet taken apart my Atlas to get a good look at parts, has anyone tried making their own diffuser to replace the stock one? Since I don't yet know exactly what the stock one looks like, I can't yet come up with something that may allow a little more light to pass through...but I am trying to think of something that could be made to replace the stock diffuser.
Anybody done anything like this yet to correct the low UV readings?
I did do a test like nincehelser did, and shined a flashlight on the sensor, and it went right up to 15. So, I know the sensor itself is working. It does just seem to me (as others pointed out) that too much light is being filtered by the diffuser.