Weather Underground dismissing barometer corrections
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BrutalGoerge
Jan 25, 2017, 12:34:08 AM1/25/17
to weewx-user
I have an Acurite 01536 I believe is the number from the top of my head.
The barometer needs to be increased by 0.10 for it to be correct. I get in the corrections section of weewx conf and do barometer = barometer + 0.10.
Here's the weird part, after I restart weewx, the barometer shows the corrected value ONCE, then after the next update in ~5 minutes, it goes back down to the non-corrected value and keeps using that value.
Any thoughts?
gjr80
Jan 25, 2017, 12:55:13 AM1/25/17
to weewx-user
Hi,
Are you sure that your station emits barometer? Corrections can only be applied to obs that are emitted from the hardware, this can get tricky in the case of pressures as there are three that are commonly used, Station pressure (aka pressure), Sea-Level Pressure (aka barometer) and Altimeter Pressure (aka altimeter). Some hardware emits one, some hardware emits one of the others or more than one and so it goes on. By default, if weewx is able to it calculates any of the missing pressures. So it can be hard to tell what is coming from the hardware as you may see all three in your output. Looking at the Hardware Guide I see that the other Acurite models emit Station Pressure (ie pressure) and weewx calculates barometer and altimeter. I realise that the 1536 (if that is what you have - you didnt seem too sure) is not listed but....
In the absence of any other guidance you could try applying your correction to pressure instead of barometer. Or maybe someone with a 1536 will come along....
Gary
Are you sure that your station emits barometer? Corrections can only be applied to obs that are emitted from the hardware, this can get tricky in the case of pressures as there are three that are commonly used, Station pressure (aka pressure), Sea-Level Pressure (aka barometer) and Altimeter Pressure (aka altimeter). Some hardware emits one, some hardware emits one of the others or more than one and so it goes on. By default, if weewx is able to it calculates any of the missing pressures. So it can be hard to tell what is coming from the hardware as you may see all three in your output. Looking at the Hardware Guide I see that the other Acurite models emit Station Pressure (ie pressure) and weewx calculates barometer and altimeter. I realise that the 1536 (if that is what you have - you didnt seem too sure) is not listed but....
In the absence of any other guidance you could try applying your correction to pressure instead of barometer. Or maybe someone with a 1536 will come along....
Gary
BrutalGoerge
Jan 25, 2017, 1:43:27 AM1/25/17
to weewx-user
The weewx html page uses the pressure variable. That seems to display correctly. Though I played with it and tried changing pressure in the corrections section, and while that changes the weewx html page, it doesn't affect the weather underground one.
Changing barometer causes it WU change, but seems to work after the first update, but like I said, it changes the weather underground display once, then ignores it. EX: WU shows 30.00 inHg, I want it to show 30.10, so I do barometer + 0.1 in the conf, restart weewx, WU then shows 30.10 in as desired, but then 5 minutes later shows 30.00 again.
It's not a huge deal, just sort of weird that it works for 1 update period.
As for the model of the station, it's definitely an 01536 so I am not sure what the unit.
gjr80
Jan 25, 2017, 1:56:58 AM1/25/17
to weewx-user
Just out of interest how are you posting to WU? with rapid fire? Shouldn't matter as weewx should still use the corrected data. You could try setting debug=2 in weewx.conf, then stop/start weewx. You should then see the URL that weewx is using to post to WU. That may help to work out if the issue is WU or within weewx.
Gary
Gary
Andrew Milner
Jan 25, 2017, 3:03:31 AM1/25/17
to weewx-user
You can probably get 'odd' things happening if the station emits partial packets - depending on whether software or hardware is set as being preferred or specified. If set for hardware preferred, but it is missing, weewx will supply a value (but ignore correction) - but if present it will use the correction. Maybe the correction needs to be applied to barometer and pressure in this case - or change one of the values from hardware preferred to either hardware or software - but don't let weewx decide 'on the fly' as it were. I suspect the root cause is either a preferred setting is being used rather than an actual or hardware is specified instead of software (or vice versa). Either could conceivably give rise to corrections being used and not used intermittently.
BrutalGoerge
Jan 25, 2017, 3:04:06 AM1/25/17
to weewx-user
Not using rapidfire, since that seems to bug out sometimes on the raspi.
I started the app in debug mode, and I noticed it said barometer: none, and altimeter: 29.7 pressure:23.69
There got the url it sent, and it's trying to send the corrected barometer reading of 30.18, but then I look on the site, and it shows 30.08. Looks like WU is the issue for some reason
gjr80
Jan 25, 2017, 3:17:56 AM1/25/17
to weewx-user
Yes, that would tend to point the finger at WU. If you are not using rapid fire that rules out issues like partial packets. You said that the corrected figure was 'shown' on WU once after a restart but then reverts to uncorrected. I presume that weewx continues to post the correct value? If that is the case I think we can say almost certainly a WU issue.
Gary
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