TE923 owners: do your rain reports match your hardware console?

[Timothy Witham]

Attention TE923 owners:

Does weewx report the same rain as your hardware console?  Please report here if your rain reports are correct, or not.  Did you achieve correct values with a configured correction or no correction?

My hardware reports 7.26% more rain than weewx.

I believe the reason is that the Meade manual claimed 2 values for rain gauge resolution, neither of which match the values observed on my console. 0.03 inches would report too high and 0.6578 mm would report too low, and the latter is used by the current driver.  I am proposing changing the rain count reports to 1/36 inch based on seeing 36 bucket tips per 1.0 inches on my display.  This should improve rain reports for all users if all hardware is reporting the same units.

If you disagree and believe the current amount is correct, please speak up!  Or if you concur that a fix is needed, that is helpful too!  Thank you!

-Tim Witham, TE923 user since 2012, new weewx user.

[Michael]

Hello, Tim,
I haven't had the rain transmitter for very long and I'm almost out of rain. So the difference between station and weewx has not been noticed so far.
The short term correction in the .conf as suggested by you helped.
The data that can be received via SDR are also 0.7 mm / unit

Thank you very much for the hint. A correction of the driver would be desirable in the long run.

Michael

[Timothy Witham]

Right, this could take a while as we wait around for some rain.  :-)

The easiest way to check is to report both the console display value and weewx reported value for that same rain.  We divide those to get the correction needed.  Of course if you already have a correction configured we would need to know that too.  For example, here is how I correct the current driver:

[StdCalibrate]
   
    [[Corrections]]
        # te923.py at 0.06578 cm is lower than actual 1/36 inch bucket
        # tips.  This correction must be removed if future te923.py is
        # fixed to report actual 0.07055555556 cm per tip directly.
        rain = rain * 1.0725989

I'm also waiting for rain to confirm this works as expected.  Thanks for your response!

[gjr80]

I suspect you are correct. I had a look at both Cumulus and WeatherDisplay to see if I could ascertain how they handled T923 rain. As far as I can tell Cumulus does not support the TE923 but WeatherDisplay does. WeatherDisplay is closed source but there are a few threads re TE923 rainfall issues on the WeatherDisplay support forum. This thread starts off focussing on a separate issue but eventually there is a realisation the rain/tip is incorrect. Reply #65 provides some empirical data that supports 0.71mm/tip [(62.8mm - 55.7mm)/(89 tips - 79 tips) = 7.1mm/10tips]. Given the resolution of the console and the small number of tips I'd say this is consistent with your value.

Gary

[Timothy Witham]

Thanks for the input Gary,

Another confirmation:

I counted 167 bucket tips in my database for the month of May while the memory display on the console shows 4.64 inches.  1/36*167=4.63888889, exactly matching the console!

Tom has merged my pull request #575 so those of use with conversions will need to remove those when the new driver (0.41.1) makes it or our machines in a future upgrade.

Thanks Tom!