Loading ...
Sorry, an error occurred while loading the content.

Re: [wuhu_software_group] Re: "homebrew radiation shield"

Expand Messages
  • Rich Brunnworth
    In my case...... it does no good to compare to the NWS station at the airport because the airport is twenty miles away and doesn t match the data we get here
    Message 1 of 5 , Aug 28, 2007
    • 0 Attachment
      In my case...... it does no good to compare to the NWS station at the
      airport because the airport is twenty miles away and doesn't match the
      data we get here in the metro area.

      What I do compare myself to is the various stations within a couple of
      miles of my station. As long as I am close, I figure that my data is
      correct. You never know exactly how the other persons station is
      mounted, or how the actual weather over their location really is. This
      is really true when a rainstorm moves through and rainfall is heavier
      over you than it is over them.

      I do is compare my station temp to that of a calibrated thermometer. So
      far I've not seen more than a couple of degrees difference between the
      two, and they are in different locations on my property, and I double
      check my station rainfall against another rain gauge. Again they are
      located in different places on the property.

      Personally I consider the "quality" of my data to be 99% accurate for my
      location. Any comparison to a station that isn't within an eighth to a
      quarter mile of me is an exercise in futility as conditions may be
      different beyond those boundaries just enough to create vast differences.

      As long as the equipment being used is accurate then a persons station
      quality is 100%.

      chronarch33 wrote:
      >
      > Jeff & Others,
      >
      > I have a question for you {snip} Have
      > you compared your values with a nearby NWS station throughout the day
      > as a sanity check? I only ask this because I have a 2308 station as
      > well and have been struggling for months trying to get "quality"
      > data.
      >
    • Jeffrey C. Le Doux
      Chronarch33, et.al., Before I sent my note I checked the 4 closest stations as well as the NWS analysis graphs. There is one station that is way out, but
      Message 2 of 5 , Aug 29, 2007
      • 0 Attachment

        Chronarch33, et.al.,

        Before I sent my note I checked the 4 closest stations as well as the NWS “analysis” graphs.  There is one station that is way out, but the rest are within a degree of mine, and mine lays right on the analysis graph.  There is very little time when the sun has the opportunity to shine on the thermo/hygro sensor, and that was even before my modifications.  The most important modification, apparently was the addition of the aluminum foil on the cover to reflect the heat.  The holes merely provide a way to circulate the air.  Later this morning I will photograph the setup, and submit those photos.  (The holes will probably not be visible, but we will see. 

        Jeff L.

        The WiltonWeatherGuy

        KMEWILTO1

        CW5246

         


        From: wuhu_software_group@yahoogroups.com [mailto: wuhu_software_group@yahoogroups.com ] On Behalf Of chronarch33
        Sent: Wednesday, August 29, 2007 1:38 AM
        To: wuhu_software_group@yahoogroups.com
        Subject: [wuhu_software_group] Re: "homebrew radiation shield"

         

        Jeff & Others,

        I have a question for you and a few comments. I was reading through
        CWOP's manual and believe I noticed that errors can be as much as 6
        degrees before your data gets flagged by MADIS as being strange. Have
        you compared your values with a nearby NWS station throughout the day
        as a sanity check? I only ask this because I have a 2308 station as
        well and have been struggling for months trying to get "quality"
        data. I finally signed up for CWOP last week so I should start
        getting my QC data this week. For my modifications I started off by
        drilling holes in the cover for the 2308 so rain could not get in but
        air would be able to pass through. This did not do much. I have
        always kept it in the shade though because the temp spike were 10-15
        degrees when sunlight touched it. I then proceeded to purchase one of
        those manufatured gill plate/plastic dish radiation shields from
        AMbient Weather and moved the sensor so it was in the sun. I only
        get morning to early afternoon sun though because I live on a green
        belt so the sun dissapears behind the trees after lunch time. This
        helped a bunch but I would still get around a 5 degree spike when the
        sun hit and then it would flatten out. So I made another
        modification by cutting a hole in the 2nd to top plate and added a
        8mm 75 CFM DC computer fan that pulls the air up thus making it an
        aspirated shield. Now my temps read within exact to no more than 3
        degrees off at times from the NWS station at the airport. I
        originally had a 5 watt solar panel to run the fan but then I thought
        it would be a great idea to get a tractor/lawn mower battery to make
        it 24 hour aspiration. Well with the green belt issues the battery
        would croak after about 3 days. HAHA. SO I bought a 1.5 Amp small
        battery charger that trickle charges and acts as a DC power supply.
        Seems to be working so far. I have done all this over the past few
        weeks. Pretty fun modification. It cost me just around $120 for all
        the various goodies. So add that to the $79 for the station I now
        have a pretty decent setup for around $200.

        Here is my station data

        http://www.wundergr ound.com/ weatherstation/ WXDailyHistory. asp?
        ID=KWAARLIN6

        --- In wuhu_software_ group@yahoogroup s.com, "Jeffrey C. Le Doux"
        <jefcled@... > wrote:

        >
        > WUHU ,
        >
        > I did not want to say anything until I had several sunny days on
        record.
        > That has now occurred. I have a small shelter (will photograph
        tomorrow)
        > and the aluminum foil wrapped perforated cover that came with my ws
        2308
        > weather station ( La Crosse ).
        Despite my connectivity problems the
        following
        > is what I have been getting for weather quality reports from CWOP.
        >
        > DATE UTC * ALT * POT TEMP * DEW PNT * DD *
        FF
        >
        > * (MB) * (DEG F) * (DEG F) * (DEG) *
        (KNT)
        >
        > 28-AUG-2007 Errs * 0/35 * 0/35 * 2/35 * 0/35 *
        0/35
        >
        > DATE UTC * ALT * POT TEMP * DEW PNT * DD *
        FF
        >
        > * (MB) * (DEG F) * (DEG F) * (DEG) *
        (KNT)
        >
        > 27-AUG-2007 Errs * 0/46 * 0/46 * 1/46 * 0/46 *
        0/46
        >
        > DATE UTC * ALT * POT TEMP * DEW PNT * DD *
        FF
        >
        > * (MB) * (DEG F) * (DEG F) * (DEG) *
        (KNT)
        >
        > 26-AUG-2007 Week *-0.5(0.48)* 1.5(3.74)*0. 82(3.47)* -6.7(
        94)*0.05
        (1.53)
        >
        >
        >
        > Note that times are in UTC. The values displayed are 'Observed
        (error)'
        >
        > The error value is 'analysis - observed'. I.e. if your observed
        value is
        > higher than the computed value, then the error will be negative.
        You have to
        > pick out the reading that is in error. The row with the time
        of 'Smry' is a
        > daily summary and the data is 'mean(standard deviation)' for each
        > observation during that day.
        >
        > The 'Week' row is the summary for the preceding 7 days.
        >
        >
        >
        > As you can see, no temperature errors at all, and we have had
        plenty of sun
        > for the last couple days. The ones before these two are equally
        impressive.
        >
        >
        > Jeff L.
        >
        > The WiltonWeatherGuy
        >
        > KMEWILTO1
        >
        > CW5246
        >

      Your message has been successfully submitted and would be delivered to recipients shortly.