Hello. I’m not sure why but this post entirely slipped past the WeatherFlow staff. Apologies to you, @WLPD! And thank yous to @eric for looping me into the thread! I don’t know why the forum software did not show this as a “new” or “unread” post.
True, the hardware is finished. But for all we learned during our extensive field testing, we are learning even much more now that we’ve gone to production! One of those lessons is that the factory calibration process for the UV sensor is not perfect.
Fortunately, the Smart Weather Stations were designed to get smarter over time. We’re actively processing data and developing a continuous learning process that applies QC and auto-calibration to each individual station. We are making great progress but still have a ways to go. Thanks for your patience as we sift through all of the data coming in.
I’ve added the seven stations you’ve listed here to the beta group for the UV component of our continuous learning system. You should notice those values improve over time and the processes we’re developing using the beta group will be applied to the entire network soon.
We now have 26 stations online.
3 stations were added to the list since monitoring.
Station ID 2236 is extremely high also.
For the last 4 days 10.8 - 12.0 - 11.5 - 13.6
Station ID 4310 does not report UV.
It shows - - - for UV.
Here is a list of 26 stations and their UV.
The first 3 colums of data shows UV at clear blue sky across whole the country.
The last station (id 2167) on the list was called station Holland but is called Sluispark now and is situated in Belgium, extremely high numbers for that station.
My station is at the top id 2254.
ID
(01-07)
(30-06)
(29-06)
(06-07)
(07-07)
(08-07)
2254
8.6
8.5
8.7
9.7
10.4
8.7
2178
*9.1
12.8
12.3
11.7
2203
5.8
5.8
5.6
6.5
5.6
6.4
2170
1.3
1.3
1.3
1.5
1.3
1.4
2161
11.6
11.5
11.3
12.9
13.8
11.1
4171
6.6
6.1
6.0
7.2
7.4
7.7
4184
4.9
4.3
4.3
5.0
4.6
5.0
2190
4.5
4.3
4.4
5.3
5.5
5.0
2171
*3.8
1.4
4.2
4.2
4.2
2173
5.2
5.1
4.8
5.4
5.7
5.1
4173
11.7
11.2
5.0
11.7
5.8
11.7
4219
9.1
9.2
10.5
9.7
8.9
4214
6.5
6.4
7.7
N.A
6.5
3065
10.6
10.2
10.0
10.5
11.6
2316
6.3
6.4
7.6
6.2
8.4
2262
7.9
7.2
7.7
7.2
8.0
4236
8.4
8.0
6.4
6.1
4.9
2234
6.1
6.3
5.6
5.3
5.7
2187
8.3
7.6
7.1
8.7
7.9
9.1
2176
9.8
9.7
11.3
10.1
10.2
11.8
4224
6.6
6.5
6.6
6.7
7.4
2172
11.0
11.2
10.7
13.5
12.2
14.0
2180
4.2
4.2
4.2
4.8
4.4
5.0
2185
9.0
8.8
10.0
2236
12.0
11.5
13.6
4310
No UV
No UV
No UV
2167
13.2
12.9
13.7
14.6
13.0
15.8
Numbers were the highest taken from their UV graphs.
My sky unit uv reading seem to be much lower than nearby units. It is a clear cloudless day in the central valley of California, upper 80’s, but uv reading is only 4.7. Sky units 30 miles north in the same hot valley show 8.0, similar to other relatively nearby units. My sky is mounted on a 10 ft pole attached to the chimney of a 2 story house, so no interference by tree shade. They have consistently been low since it was installed
Any ideas?
usually that happen when your unit(SKY) does not mounted straight. or maybe something stuck on the sensor if your sky doesn’t have any technical issue.
hope the weatherflow team can help you about that.
indeed have a look at it. Is it in open skies and no shadow on it with moments ? Also did something drop on the sky ? Little bird that … you know what I mean …
Just bring it down and double check and in worst case open a ticket with WF … be patient for a reply as I can imagine the support team must be working hard with all sky’s being delivered in a short time span …
I thought about birds , so I’ll climb up and check that out this weekend. Also, was there a protective covering on the Sky unit that needed to be removed?
My guess is that there is a protective film cover over the sensor component that was not removed by the factory after soldering. From personal experience with another vendor’s sensor on a breadboard, the protective film that I forgot to remove was good for a 2-3 loss on the UV scale…
A tiny protective film on the face of the actual sensor, like this one (red tab) on a Raspberry Pi camera module:
These types of covers are used to protect components like piezo buzzers and barometer sensors from being damaged during the wave-soldering and assembly process. As I said, just a guess, since I stupidly did that with a different UV sensor component and the resulting readings were lowered by 2-3 UV points.
As an aside, it is interesting to wire up one of these sensors via I2C and hold various items in front of it in full sunlight. Even plain old (untreated) window glass will drop the reading by a point…
I have two Sky’s 800mm apart for testing. Lux/brightness readings are within 5% but there is a 20-30% difference in UV. I’m waiting for a sunny day to make some better comparisons. Its winter time so max values are not very high.
OK, I took a look at the Sky this morning. It appears to be clean(no bird visitations) and I don’t see any protective coverings. The accumulated dust was removed and the unit reinstalled to the mount. Today’s weather is supposed to be clear and hot (104 degrees) so we will see what the UV readings are at about Noon.
your Photo reveals , it looks to be inserted too low i can see the edges quite clearly , i seem to recall last two units i recieved is actually smooth and if i run my finger over the teflon i dont feel any edges as the teflon is level with rest of surrounding area or i dont see any exposed edges. this may indicate low readings as it may not be fully exposed . ps im not guaranteeing its the issue but just observing your photo
Thank you for that observation. I have not seen any other Skys to compare it to. So I’ll wait to see if anyone from WeatherFlow staff replies and then submit a ticket if they recommend that.
the teflon is on top not revealing the edges of the circular cut out as shown in your unit anyway may be nothing to do with it but just an observation of difference.
I received my SKY unit a few weeks back and it has been in service about 3 weeks. I, too, have noticed low UV readings so far. On the sunniest of days, I have yet to see a UV reading above 5. I plan on checking what has been noted previously and mounting it in a rooftop location soon to see if that improves the UV issue.
with another vendor’s sensor on a breadboard, the protective film that I forgot to remove was good for a 2-3 loss on the UV scale…
