1. Steve Mackin

    Steve Mackin New Member

    For Peter: The Taiwan GI meter is hardly "scientific". Most such things made in Asia (not including Japan) are infamous for having labels and stickers on them saying anything they want with no documentation. Example: UL or CE approvals or ISO when none of such has been certified.

    The master Solarmeters are actually calibrated ±4% ref NIST. We bump that up to ±10% on UVB label simply to account for any possible uncertainty in transferring the master reading to saleable units. In reality the saleable units read exactly same as master within 1 or 2 significant digits as shipped.

    The "250% difference in accuracy" above is fuzzy relative (not absolute) math. In absolute terms... IF the actual UVB was say 400 µW/cm² then minus 10% worst case = 360. If minus 4% then 384. The 360 = 94% of 384. Therefore absolute minus difference reverts back to only 6% - not 250%! And besides - the 10% vs 4% would hardly account for the gross error of super high 11000 µW/cm² (11.0 mW/cm²) UVB as presented on the black helicopter site.
     
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  2. Leifer

    Leifer Senior Member

    I have the 6.2, bought a month ago. Thanks !
     
  3. Steve Mackin

    Steve Mackin New Member

    OK - Ten-Four... good. You'll have the whole package then. Enjoy!

    This page shows 6.2 meter readings from all over the world. The meter in pics have a black label... from before they were changed to iguana green color. http://www.uvguide.co.uk/uvinnature.htm
     
  4. Leifer

    Leifer Senior Member

    I have been thinking about "where" in Los Angeles to take the UV readings, on the solstice, Sunday, June 21st...

    1) - My backyard, (1300ft elevation, ~30miles inland, open area but one 2x story condo is to the E, and some trees to the W, and S.)
    2) - My father's condo complex (Marina del Rey, sea level, possible tall buildings to the N/NE)
    3) - Griffith Observatory (1100ft elevation, not many obstructions)

    Looks like clear skies everywhere, except possible overcasting in the morning at sea level.

    Unless convinced otherwise, I'm thinking the Griffith Observatory....especially because they will be having some solstice events.....and possible experts to chat with.
    If I want to be a complete and proper nerd, I'll bring a fold-out table for my UV gear and, and some printed historical UV records to use as discussion topics. I won't mind chatting with anyone who is interested.
    (oh, and a copy of Dane's articles ??)
    I'll be armed with my good video gear also. (Batteries !!!!)....maybe a friend to help.
    If you are in the LA area, let me know. (yes, it's Father's Day....my dad is out-of-town)

    http://www.griffithmedia.org/skyreport/
     
  5. Steve Mackin

    Steve Mackin New Member

    Well - that sounds like fun! Especially if Griffith. Even at 1100 feet there will only be maybe 5% more UV than at sea level. No where near the monster levels that started this thread. Enjoy. And don't forget your fold-out white table!

    You should take a set of readings today in your 1300 ft backyard as reference... solar noon-ish. Then maybe at sea level when you have time - but inland not Marina del Rey because near coast there is always more water vapor in the atmosphere absorbing UV somewhat.
     
  6. Leifer

    Leifer Senior Member

    Change of plans.....I'm doing it in my front yard. I couldn't find a sucker to help me schlep all that gear around.
    Plus there is this thing called.......120v AC.
     
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  7. Steve Mackin

    Steve Mackin New Member

    Summer equinox here in MI... solar noon 1:30 pm... elevation a mere 600 feet... 42°N.....out in open:

    Model 5.0 UVA+B: 5.4 mW/cm² (5400 µW/cm²)
    Model 6.2 UVB: 394 µW/cm² (7.3% UVB)
    Model 6.5 UVI: 8.3
    Model 8.0 UVC: 000 µW/cm² (of course)

    Sky was pale blue with high humidity. Highest I've seen at my location near June 21 deep blue sky low humidity:

    UVA+B: 5700
    UVB: 435 (7.6% UVB)
    UVI: 8.8
    UVC: 000

    So today was no record setter! You will get higher readings near LA (34°N) and 700 feet more elevation.
     
    Last edited: Jun 21, 2015
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  8. Leifer

    Leifer Senior Member

    weather_info.
    I did my readings today (monday) instead of yesterday (Father's Day).
    I video taped them, and will be editing one or two videos in the next couple of days.
    Spoiler alert.....the readings I got, were very similar to yours.

    I'd also like to point out that if indeed the ozone layer was not what it used to be, the UVC values would have changed as well.....and it appears they have not changed to any significant extent. (I got between 0.000 and 0.002 UVC on a different meter brand (Vilber Lourmat, mw/cm2, @254nm).
     
    Last edited: Jun 22, 2015
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  9. Leifer

    Leifer Senior Member

    I am realizing that to cover the complete subject in just one (1) video.....will result in a long video.
    I want to keep it short-and-sweet. I realize the attention-span of most people.
    That's why I'll be doing a short version, and a longer version.
     
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  10. Steve Mackin

    Steve Mackin New Member

    No problem with the spoiler alert... I only expected them to be a bit higher than mine because 700 more feet elevation would not make much difference. But about 7000 more feet certainly would. Your lower latitude should have bumped them up some... if air was "clear". However your forecast UV Index was only 7.6 so most likely the atmosphere was a bit "thick" with haze or something today according to NWS/NOAA.

    Please humor me and try a Schott WG280 filter above your "VL" UVC sensor next time it is reading 0.002 mW/cm² (which would be 2 µW/cm² on a Solarmeter Model 8.0 UVC). I have never seen above 000 to sun. The WG280 will block real UVC. So if the VL still reads 0.002 with the Schott filter, then that is not actually UVC.

    There is a site that shows daily O³ layer thickness in DU (Dobson Units) by city or zip code... but it slipped my mind. Average is ~320 DU as I recall. In any event... even if it was "thin" near say 280 DU... the regular atmosphere would/should absorb whatever UVC made it through the ozone layer - as far as I know.

    A thinner than normal O³ layer however WILL increase your UVB and UVI readings - all other factors being typical.
     
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  11. Leifer

    Leifer Senior Member

    I have a steep bandpsss filter @245nm that could cover the sensor, and there would be some transmission loss.....but I think you are referring me to an "allpass, with the low cutoff being at 280nm" ??
     
    Last edited: Jun 22, 2015
  12. Steve Mackin

    Steve Mackin New Member

    No... for this purpose you need to block out all UVC below 280 nm - not just block (or pass) peak sterilization wavelength of 254 nm. Besides... no 254 nm photons could ever make it through even 1 atmosphere (sun zenith 0° straight overhead).

    IF the ozone layer was so thin as to allow any UVC through... it's bandwidth would be up around 275-280 nm - not down at 254 nm. Unless you are under an O³ hole in Antarctica, the lowest detectable µW solar irradiance is at about 290 nm. Even at the south pole I doubt any 254 nm rays would be present. They would sterilize all the polar bears! Wait: Or are they only near the north pole? Maybe I'll email Algore and ask him....
     
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  13. Steve Mackin

    Steve Mackin New Member

    Today was perfect deep blue sky with a few puffy white clouds. Low humidity, no haze... so these will likely be the highest possible solar noon readings for 2015 in Michigan:

    UVA+B: 6.0 mW/cm² (6000 µW/cm²)
    UVB: 416 µW/cm² (416/6000 = 6.9% UVB)
    UVC: 000 µW/cm²
    UVI: 9.4
     
  14. Efftup

    Efftup Senior Member

    Yeah North Pole for Bears, just edit it to say penguins before anyone notices.
     
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  15. JDubyah

    JDubyah Member

    I don't know if this deserved its own thread, but it looks like the HAARPreport guy has followed up on Dane's UVA/UVB/UVC meter-readings with his own, claiming that "Deadly Ultraviolet has increased, by 500% to 7000%, in only 13 years."

     
  16. Mick West

    Mick West Administrator Staff Member

    From the above video:
    I think all that demonstrates is just how variable those meters are. The UVB readings go from 0.17 to 1.8 for readings taken seconds apart.
     
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  17. skephu

    skephu Senior Member

    I wrote a comment to the video but he deletes criticisms and bans people who criticize his stuff. (Quite common behavior from conspiracy theorists.)

    There are many problems with his video. He got the 2002 paper wrong as he divides the April UVB reading by the July UVA reading.

    He uses this single 2002 paper as his historical reference. But the maximum UVB value reported in that paper (40 microwatts/cm2) seems to be on the low end of the usual ranges. (It was measured in India, maybe air pollution filtered the UVB?) This page reports a number of UVB measurements (all before 1993) at various locations, and the highest values are around 260 microwatts/cm2:
    http://www.anapsid.org/jamesball.html

    The normal UVB/UVA ratio is actually around 5%, not 0.6% as he claims. Which also means that his measurements with the Solarmeter and the "National Biological Corp." instruments are nothing out of the ordinary.

    The sensors he uses with the Spectroline instrument measure at particular wavelengths, not ranges, so they are not UVA or UVB meters.

    For the Accumeter, he uses sensors that are not UVA and UVB sensors at all. UVA is defined as 320 to 400 nm and UVB as 290 to 320 nm. But the instrument measures 340 to 380 as B and 380 to 420 as A, completely different.

    For his UVC measurement, he uses a sensor for 254 nm, but these sensors are for measuring UV lamps, and their spectral responses may well overlap with the UVB region; they are not supposed to be used for measuring sunlight.

    Essentially, various instruments use sensors with different spectral responses. Measurements are only comparable if one uses sensors with the same spectral response.
     
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  18. skephu

    skephu Senior Member

    It seems to me that the authors of the 2002 article that the HAARP report guy cites may have misread their own UVB readings.
    The article is Balasaraswathy et al. here.

    They say that the maximum UVB level they measured was 40 microwatts/cm2.
    But they also cite a French study and they claim that it measured a maximum of 15 microwatts/cm2.
    However, the French study (abstract here) says that they measured 0.15 milliwatts/cm2, which is 150, not 15 microwatts/cm2. Looks like Balasaraswathy et al. made an elementary mistake.

    Also, the Balasaraswathy et al. study obtains UVA/UVB ratios around 200, while it should be more like 20.
    So I suspect they didn't even read their own instrument right, and they are off by a factor of 10.
    But maybe not. The only reliable way to measure the irradiance is to use a spectroradiometer to measure the whole spectrum and then integrate over the corresponding ranges. But Balasaraswathy et al. just used a simple handheld meter with two sensors. Unfortunately, this paper comes up as a top hit when one searches for papers on the UVA and UVB content of sunlight.
     
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  19. Hama Neggs

    Hama Neggs Senior Member

    Any point in trying to contact the authors of the 2002 paper?
     
  20. skephu

    skephu Senior Member

    Actually, I have looked into this more, and the instrument reports the measurement in microwatts/cm2 units, so it cannot be misread. However, the sensor they used is not a UVB sensor but a biologically weighted UVB sensor. That means it applies a weighting function to reproduce the biological effectiveness (to make skin red) of the UV radiation. Because of this, it actually reports only a fraction of the actual UVB.
    Now what The HAARP Report guy measured by the Solarmeter instrument was not biologically weighted.
     
    Last edited: Oct 18, 2015
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  21. Hama Neggs

    Hama Neggs Senior Member

    This whole UV measuring thing seems difficult and fraught with potential for error. Of course, people like the HAARP Report guy refuse be believe he could ever make a mistake.
     
  22. Jay Reynolds

    Jay Reynolds Senior Member

    Anonymous people like this one don't have to be responsible for errors.
     
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  23. skephu

    skephu Senior Member

    New measurements of UVC on geowatch:
    upload_2017-2-28_15-56-15.

    [​IMG]
    Said to be by "former NASA engineer". Values are supposed to be microwatts/cm2.

    http://www.geoengineeringwatch.org/...zone-layer-a-former-nasa-engineer-speaks-out/
     
    Last edited by a moderator: Feb 28, 2017
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  24. Mick West

    Mick West Administrator Staff Member

    UVC is 100-280nm, these graphs go from 250 to 300

    Anyone know what the "Series" refer to? Just different readings?

    I'd be interested to see what the data looks like for a nighttime reading. It's quite possible this is just the numbers the sensor puts out even when there's no radiation. It's not at all clear what it represents.
     
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  25. skephu

    skephu Senior Member

    The February 18 data seem to be a lot noisier than the February 12 data. The average seems to be the same or even lower than the February 12 data. In the February 18 graph, there are lots of low spikes in the 0.7-0.8 region (dark blue), these are completely missing in the February 12 graph.
    And yes, what are the "series"?
    Unfortunately this "former NASA engineer" did not adequately document his measurements. He seems to be more interested in "anti-geoengineering" propaganda than in documenting the measurements.
     
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  26. Trailblazer

    Trailblazer Moderator Staff Member

    Geoengineering Watch says:

    This is not true. Northern hemisphere ozone levels are monitored daily and can be viewed at the Nasa Goddard Arctic Ozone Watch page:

    https://ozonewatch.gsfc.nasa.gov/NH.html

    This is the most recent view:

    View attachment 25603

    Comparing the map to the February average from, say, 10 or 20 years ago, it seems there is rather more ozone up there now:

    View attachment 25604 upload_2017-3-1_12-48-45.
     
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  27. Trailblazer

    Trailblazer Moderator Staff Member

    The article also misleadingly includes this graph as evidence that the ozone hole is getting bigger:

    [​IMG]

    While the article doesn't specify this, this graph is actually for the southern (Antarctic) ozone hole, and it was from 2015 - it appeared, in, for example, this Australian news article in October 2015, which explains:


    The anomalous 2015 Antarctic hole shows up on this graph at the Ozone Watch site:

    upload_2017-3-1_13-4-40.

    but the 2016 levels were pretty well exactly in line with normal levels over the past four decades:

    upload_2017-3-1_13-6-2.

    So, in summary:

    • Yes, there was an anomalously large Antarctic ozone hole in 2015, but it was down to unseasonably cold weather (something that doesn't really fit with Dane Wigington's idea of runaway global warming). Since then, ozone levels have recovered so that the hole is of average size.
    • No, ozone levels are not falling over the northern hemisphere: in fact, the ozone layer here is in better shape than it was 10 or 20 years ago.
     
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  28. Mick West

    Mick West Administrator Staff Member

    Geoengineeringwatch are continuing to push this idea:
    http://www.geoengineeringwatch.org/geoengineering-is-causing-lethal-uv-radiation-exposure/
    Again this just looks like sensor noise. They should see how the sensor responds in this range in A) darkness and B) indoor artificial bright light.
     
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  29. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    Could be aliasing of a grating. See the end of 8.7.2. here:
    https://books.google.co.uk/books?id=11iz-UKrWf4C&pg=PA262&lpg=PA262&dq=grating+order+aliasing&source=bl&ots=V5Dqy5aHvA&sig=Qtgt7omt8Vlh2PkMS0zQed1AjC8&hl=en&sa=X&ved=0ahUKEwifxbb2qvPVAhXDJlAKHZHKCdoQ6AEIMDAB#v=onepage&q=grating order aliasing&f=false

    20170825-144952-6fjg0.
     
    Last edited by a moderator: Aug 25, 2017
  30. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    The software manual mentions subtracting a background scan, and also a calibration file. I don't think the instrument was intended for measuring non-existent UVC levels.
    https://www.intl-lighttech.com/sites/default/files/pdf/manual/SpectrILight_III_Manual_Jan_2012.pdf

     
  31. Mick West

    Mick West Administrator Staff Member

    2.5 years ago Dane suggested that extreme UV radiation was stripping the bark off trees. As an example he showed this tree that had some kind of damage scar in a Redding, CA, parking lot
    20170826-152035-0rj2a.

    It's this tree:
    20170826-152659-xe3qc.

    And it seems to be doing just fine in the Street View. You can clearly see the scar:
    https://www.google.com/maps/@40.587...4!1sT6n-2bhJwPkQn9rI2N8rcQ!2e0!7i13312!8i6656
    20170826-153012-a13cx.

    I was just in Redding, I should have stopped to check it out.

    The problem (for Dane Wigington) with making apocalyptic predictions is that they are testable by waiting. Here he's saying there's so much UV radiation it's killing all the trees. And yet, no the drought is over (for a year) the trees are doing better. Most trees are not dying, and I suspect this particular tree looks pretty much the same.
     
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  32. Cedtomcat

    Cedtomcat New Member

    A scarred tree in a parking lot? That can only be UVs. It's impossible that it could come from... a car...
     
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  33. Ross Marsden

    Ross Marsden Senior Member

    Are these scars on all the other trees in the parking lot?
    And are they on the sunny side of the tree?
     
  34. Cedtomcat

    Cedtomcat New Member

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