Author Topic: Current east coast system rain totals /Comparing gauges...  (Read 584 times)

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Offline DoctorKnow

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Current east coast system rain totals /Comparing gauges...
« on: July 25, 2018, 09:29:26 AM »
I wanted to share the accuracy of 3 different rain gauges I am using at this time as we have had over 4 inches of rain over the past few days. These instruments are the Acurite Atlas, Acurite 5n1 and a Fine offset WH2310 branded as Excelvan.
It is still raining, but should be stopping in the next hour... however I am going to total things now since it really won't make a difference if a couple more tenths comes down.
The Atlas I have NOT calibrated since installing. The 5in1 I calibrated some in the negative direction on 3 different occasions to get the accuracy I have now. In lighter rain, it can read low by as much as .08 , but in heavy rain it can pass by the other two tippers by about .15 or so.

The fine offset rectangular gauge I had to calibrate up from default of 1.10 to 1.27 on the console.
Totals for the event....
Atlas - 3.90
5n1 - 4.17
FO - 4.20
manual gauge- 4.25


Offline Old Tele man

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Re: Current east coast system rain totals /Comparing gauges...
« Reply #1 on: July 25, 2018, 10:29:01 AM »
If those ratios hold up over multiple samples, you can come up with a scaling formula to compare results:

3.90 = Atlas ... (91.8%)
4.17 = 5n1 ... (98.17%)
4.20 = FO ... (98.8%)
4.25 = manual gauge (100%)
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Offline catdon

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Re: Current east coast system rain totals /Comparing gauges...
« Reply #2 on: July 29, 2018, 12:53:34 PM »
We recently had a record setting deluge where 4.45" fell in a short period of time....most of it in about 2 hours and about 1.50" in 20 minutes. I used to calibrate my davis gage with my manual gage on occasion but haven't done it in a long time. Also with the gages now being at my sisters  house,  I rarely  have the opportunity to even check the manual gage anymore...I was able to compare the two after the current storm and was surprised that after 4.45" of rain that there was a scant 0.03" difference. With so much rain in a short period of time, I was pleasantly surprised.
Don
Staten Island, NY

Offline DoctorKnow

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Re: Current east coast system rain totals /Comparing gauges...
« Reply #3 on: July 29, 2018, 01:06:47 PM »
Since posting, I calibrated my Atlas and now it reads within 3 hundredths of my manual gauge. I just turned the screws about a quarter turn. In the last 2 days I had 1.90 in the manual, and the Atlas read 1.87". The fine offset read 1.84" - I also calibrated the 5n1, but it read a little higher, coming in at around 2.10" It is quite difficult to zero in.


Offline ocala

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Re: Current east coast system rain totals /Comparing gauges...
« Reply #4 on: July 29, 2018, 01:17:15 PM »
We recently had a record setting deluge where 4.45" fell in a short period of time....most of it in about 2 hours and about 1.50" in 20 minutes. I used to calibrate my davis gage with my manual gage on occasion but haven't done it in a long time. Also with the gages now being at my sisters  house,  I rarely  have the opportunity to even check the manual gage anymore...I was able to compare the two after the current storm and was surprised that after 4.45" of rain that there was a scant 0.03" difference. With so much rain in a short period of time, I was pleasantly surprised.
That's nothing short of amazing!
I have had roughly the same scenario at my place and the Davis was about 20% off.

 

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