As someone who has problems with the occasional(scoff!) spike value; I
highly recommend Darryn's - beta - qc.py replacement (links below). It may
not fit your comfort level, and I don't think you could use it for rain or
any other instrument (wind?) that can have spikes as a matter of course,
but then again...

As you're aware, if you have failing hardware or similar underlying
problems then it's not necessarily the preferred solution - but when you
consider that an errant value can be caused by many things, and have way
more impact on the historical data,  database, graphs than it should; then
ignoring them is a valid option.
I get spikes in my rain values, but don't use Darryn's qc.py for them -
barometer and outside humidity though? It's been absolutely brilliant for
those sensors. I'm working on replacing them, as something is amiss there,
but the qc spike detection has allowed me to spend some valuable time
finding and isolating the cause and determining my options, the best way to
go for my setup. In the meantime, I still have a working system with the
outliers banished to the bit bucket.

If you're willing and able to replace the stock weewx qc.py with the
qc-spike.py of Darryn's, and spend a bit of time understanding it and
tweaking it to suit your circumstances, it could repay you (in fact:
anyone) with some nice, clean data.

As Gary says, the StdQC service is fairly basic, but I feel this qc-spike
addition enhances that service very nicely, and it's not _too_ complicated
to implement.

Links to Darryn's qc spike posts...
https://groups.google.com/d/topic/weewx-user/p6iGhRUxxa4/discussion
https://groups.google.com/d/topic/weewx-development/vfD9WfHLSaI/discussion


Cheers
 Glenn

rorpi - read only raspberry pi + weewx: now with scripts
<https://github.com/glennmckechnie/rorpi-raspberrypi>

On 13 April 2017 at 18:03, Auchtermuchty Weather <[email protected]>
wrote:

> Thanks, the backfill in progress and I have a feeling my weather station
> might have problems as it's clear the erroneous readings have greatly
> increased.
>
> I have a question about the QC.  It's clear what the temperature values
> (for example) should be, but rain is a cumulative thing, so over what
> period of time?  I'm guessing between readings, but to me that doesn't make
> sense with a default QC value of 60 inches!
>
>
> On Wednesday, 12 April 2017 09:20:06 UTC+1, Auchtermuchty Weather wrote:
>
>> I am getting the odd spike in my readings, for example:
>>
>>
>>                    TEMPERATURE (C), RAIN (mm), WIND SPEED (knots)
>>
>>                                          HEAT   COOL         AVG
>>       MEAN                               DEG    DEG
>> WIND                   DOM
>> DAY   TEMP   HIGH   TIME    LOW   TIME   DAYS   DAYS   RAIN  SPEED
>> HIGH   TIME    DIR
>> ------------------------------------------------------------
>> ---------------------------
>> 01    3.5   13.1  11:12   -1.1  04:31   14.8    0.0    0.0    0.4    6.0
>> 07:19     22
>> 02    4.3   13.4  05:56   -0.7  00:02   14.0    0.0  148.8    1.8   44.9
>> 05:56     25
>> 03    4.3   11.9  11:31   -2.3  07:56   14.0    0.0    5.1    0.7    8.6
>> 22:43    191
>> 04    5.2    6.7  15:30    4.0  08:30   13.2    0.0    9.9    0.7   12.6
>> 09:50    207
>> 05    5.6   10.3  15:25   -0.2  23:51   12.7    0.0    3.6    0.0    3.3
>> 07:37    108
>> 06    5.2   16.7  14:55   -0.3  01:18   13.1    0.0    1.2    0.1   43.5
>> 15:34    130
>> 07    5.1   12.4  11:19  -15.1  08:56   13.2    0.0  807.9    0.4    8.0
>> 16:15     77
>> 08    7.3   13.3  11:31    4.8  07:30   11.0    0.0    2.4    1.7   19.2
>> 11:44    360
>> 09    8.0   14.3  14:26    2.7  23:51   10.3    0.0  271.8    1.2   11.9
>> 08:48    345
>> 10    6.0   10.2  16:02    1.2  02:30   12.4    0.0   76.8    0.1   26.4
>> 07:35    249
>> 11   10.2   16.3  14:02  -38.0  15:32    8.1    0.0  625.5    0.6  128.9
>> 06:15     29
>>
>>
>> There is no way there has been a wind speed of 128.9 knots!
>>
>> I can't remember how to fix these, nor can I remember if there is a setup
>> somewhere to reject readings outside the parameters.
>>
>> --
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