WXforum.net
Weather Station Hardware => Davis Instruments Weather Stations => Topic started by: jgentry on May 29, 2018, 05:00:59 PM
-
Hey Gang,
I’ve noticed that my RainWise 111 gauge has been under reporting rainfall totals during light rainy conditions. I’m using my CoCoRAHS gauge as the “standard.” As Alberto came through central Alabama, my CoCoRAHS gauge reported a total of 3.79” whereas my RW gauge recorded 3.48”. I’m curious to what could be causing this? When I “adjust” the rain readings on the gauge to match up with my CoCoRAHS, the RW reports all the tips just fine.
-
Slightly out of calibration. Start by turning screws 1/2 tun out (on tipper screws) making them taller and tipper easier to tip...Do both equally. Tipping buckets are rarely perfect because of varying rain rates, Idea is find that happy medium somewhere around +/- 3% sweet spot.
-
Thanks! I am surprised how quickly the gauge needs calibration. When I first had the RW gauge installed late last year, it reported around the same or a tad more than CoCoRAHS.
-
You can buy a calibrator, or make one yourself, as I did. The RW takes exactly 800ml of water to equal 1" of rain.
-
Thanks! I am surprised how quickly the gauge needs calibration. When I first had the RW gauge installed late last year, it reported around the same or a tad more than CoCoRAHS.
My 2 gauges have been pretty good but a yearly tweak with moving parts isn't abnormal.
You may try 3/4 turn since you are about 9% low at slow rain rate. Theoretically will increase tips around 11 for 3.7" rainfall would of made you real close.
-
Thanks! I am surprised how quickly the gauge needs calibration. When I first had the RW gauge installed late last year, it reported around the same or a tad more than CoCoRAHS.
You may try 3/4 turn since you are about 9% low at slow rain rate. Theoretically will increase tips around 11 for 3.7" rainfall would of made you real close.
Or....as with Weatherlink, you can simply go to the calibration page and dial in whatever correction factor you want. Don't know if the console is capable of this or not.
-
Yes and something I forgot about. Double check gauge level first thing. That could be the culprit especially this way...
[ You are not allowed to view attachments ]
-
The gauge looks fairly level to me...
-
The next question is does my screws look level or not?
-
The gauge looks fairly level to me...
Not even close. Remember, this is water, it takes nothing to make it move with gravity.
Don't use the top portion of the rain cone collectors for leveling, they might not possibly be the same height, use the base. And lets get the bubble centered better than that....
-
The gauge looks fairly level to me...
Humm, it looks unlevel to me.. 1/4 bubble off or so which is a lot.
I checked my level and its dead center.
That was my level when I first started working in 1973 so it looks rough...
-
Thanks guys! It’s off some and isn’t perfect but with this current set up, it’s the best I can do. However, I did raised the screws up a fairly good bit and hoping it will offset any issues that arises due to the gauge not being perfectly level. I might be wishy washy with this. lol
Here is a picture of the level on the base of the gauge.
-
Thanks guys! It’s off some and isn’t perfect but with this current set up, it’s the best I can do. However, I did raised the screws up a fairly good bit and hoping it will offset any issues that arises due to the gauge not being perfectly level. I might be wishy washy with this. lol
Here is a picture of the level on the base of the gauge.
It's still pretty bad. You'll never truly give your tipper a chance to be accurate as it can be until you level it out better than that, adjusting screws or not. I simply used washers to level mine.
-
Was able to get a few rain/storms events with varying rain rates after I did what I did. So far, the rain measurement difference has only been +/-.01" between the RW and manual gauge. Sometimes they have read the same. Hopefully that means I won't have any issues in the near future.
-
Had a good rain today and my adjusted RW had 1.38” and my CoCoRaHS gauge had 1.33”
It’s been working good so far.
-
I shoot for +/- .03 per inch of rain on tipping bucket vs NWS standard 8" or Cocorahs 4". The 8" usually records little more .01 vs Cocorahs so you are very close.
-
Question from below thread.
Exerpt here I have question about:
"Or....as with Weatherlink, you can simply go to the calibration page and dial in whatever correction factor you want. Don't know if the console is capable of this or not."
My question is. Is this calibration factor available with weather link live? If so where do I set this?
-
Question from below thread.
Exerpt here I have question about:
"Or....as with Weatherlink, you can simply go to the calibration page and dial in whatever correction factor you want. Don't know if the console is capable of this or not."
My question is. Is this calibration factor available with weather link live? If so where do I set this?
I can't help with WL I use Cumulus software and yes with Cumulus you have options for correction factors. The Cumulus software uses a multiplier normal is 1.000 so if the tipping bucket is running .10" per inch high you would set the calibration at (0.900) or if running .10" low (1.100) etc.
-
Thanks. I will soon setup meteobridge on pi and have question to meteobridge users. Is the calibration set the same way on meteobridge? Example of offset
0 and factor of 1.1 if running 10% low?
I am 99% sure but just want to confirm
Thanks