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WeatherCat => WeatherCat General Discussion => Topic started by: oamaru on February 23, 2020, 12:26:55 am

Title: Rain Guage calibration in WeatherCat
Post by: oamaru on February 23, 2020, 12:26:55 am
Hi All.
I have a Tesa Weather Station.  It has a tipping bucket rain gauge without any manual adjustments.  I have disassembled, cleaned and lubricated the mechanism, but it is reading low by about 5%.  In WeatherCat 2.4.4 I can make calibration adjustments for most things except for the rain gauge.  Is there any way of adjusting the accuracy? 
Cheers
Title: Does not appear to be adjustable. (Re: Rain Guage calibration in WeatherCat)
Post by: elagache on February 23, 2020, 10:53:59 pm
Dear oamaru and WeatherCat faithful,

I have a Tesa Weather Station.  It has a tipping bucket rain gauge without any manual adjustments.  I have disassembled, cleaned and lubricated the mechanism, but it is reading low by about 5%.  In WeatherCat 2.4.4 I can make calibration adjustments for most things except for the rain gauge.  Is there any way of adjusting the accuracy? 

As you say, WeatherCat allows you make calibrations adjustments for quite a few station data sources.  Alas, I checked the manual and poked around the WeatherCat preferences and I don't find any way to adjust the rain gauge values.  Any hope that you could solve this problem by working once more on the tipping bucket mechanism itself?

Sorry, Edouard
Title: Re: Rain Guage calibration in WeatherCat
Post by: Randall75 on February 24, 2020, 01:32:12 am
Hi Oamaru and Edouard If there is any adjustments most are done on the console of the weather station that you are using if that is even possible on the one you are using Oamaru


cheers  [cheers1]
Title: Re: Rain Guage calibration in WeatherCat
Post by: xairbusdriver on February 24, 2020, 02:26:46 am
I don't know of any way to adjust the rain gauge in WC, but I do question the "lubrication" of the tipping bucket. I can not swear to it, but I don't think the Davis 'bucket' had any "lubrication" on it when I bought it some 5+ years ago. I am positive that I have never read any instructions that it should have any "lubrication" nor have I done anything more than clean out some sediment in the buckets.

Many kinds of "lubrication" are petroleum based but even other types can be affected by temperature. Usually that means a thickening of the lubricant. In a tipping bucket (seesaw) design, where extremely small weights are concerned, that could easily cause the bucket(s) to delay their normal movement resulting in a lower than normal rate of movement (a few extra drops required for each 'tip'). While that could cause a lower amount report (more drops remaining in the bucket when the rain stops), it would also result in lower rate reports.
[rainyluck]

On the other hand, perhaps your Tesa hardware is different, but I would suggest checking any manual or contacting their support documents. [tup]

On the third hand, I wonder if many of us maintain two different methods of measuring precipitation (or more than two identical hardware kits) so that we might be aware of any differences. Those of you that use the standardized, manual, calibrated rain gauges certainly have an advantage there. ThU32:-)
Title: Try WXForum? (Re: Rain Guage calibration in WeatherCat)
Post by: elagache on February 24, 2020, 10:06:26 pm
Dear oamaru, Randall, X-Air, and WeatherCat station caregivers,

Perhaps this is a good question to ask on another general interest weather forum.  Many people like WXForum:

http://www.wxforum.net/ (http://www.wxforum.net/)

That forum has many more subscribers and a lot of traffic.  There might be others who have your Tesa station and run into the same problem.  They might be able to suggest a solution from past experience.

Cheers, Edouard  [cheers1]
Title: Re: Rain Guage calibration in WeatherCat
Post by: xairbusdriver on February 26, 2020, 03:34:46 pm
BTW oamaru, how are you measuring/calculating the difference in your rain measurements? In other words, what are you using for the "true" values? Do you have multiple rain collectors? What type(s)?