Re: [weewx-user] Re: Barometric pressure correction the right way

I do not recall where I came across the fact that it is temperature compensated. At some point I thought perhaps the indoor sensor was trying to provide a barometer reading and I placed it outside in a sheltered area, and imported it into weewx as barometer and still it was all over the place.

Re: [weewx-user] Re: Barometric pressure correction the right way

@Louis De Lange, thanks for mentioning this. By any chance, do you recall where you read that FineOffset was using indoortemp for pressure calculations? On Sunday, January 14, 2018 at 2:35:33 PM UTC-5, Louis De Lange wrote: > > As a previous owner of a Fine Offset station I can confirm that I

Re: [weewx-user] Re: Barometric pressure correction the right way

Louis - thanks for restoring my sanity!! Yes, it is a FineOffset which I have got. In the summer I see the issue when I turn the AC on and in winter when I light the kerosene stoves!! So, it's a faulty station design - which was, I will admit, a conclusion I was coming to following Tom's

Re: [weewx-user] Re: Barometric pressure correction the right way

As a previous owner of a Fine Offset station I can confirm that I noticed this same behavior. Living in Canada where our homes are heated, I could clearly see the altimeter reading (my station did not support barometer correction to sea level) seesaw with the furnace operating and shutting

Re: [weewx-user] Re: Barometric pressure correction the right way

​The gauge in your station always reads absolute pressure.​ But, to compare it everyone else's barometer, which may or may not be at the same altitude, you "reduce" is to sea-level altitude. That corrects for altitude, and improves your ability to compare your pressure to a nearby neighbor. The

Re: [weewx-user] Re: Barometric pressure correction the right way

Andrew Milner writes: > I ask the question because whenever I put the heating on I see a change to > the barometer readings on my graphs which implies to me that the pressure > is changed (it appears to fall as the temperature rises). My console is This seems

Re: [weewx-user] Re: Barometric pressure correction the right way

Would be nice to have it AS a Option in the next release. Thanks -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more

Re: [weewx-user] Re: Barometric pressure correction the right way

I ask the question because whenever I put the heating on I see a change to the barometer readings on my graphs which implies to me that the pressure is changed (it appears to fall as the temperature rises). My console is 2/3 up the wall (too high to even read, but good for sensor reception!)

Re: [weewx-user] Re: Barometric pressure correction the right way

As far as I was aware the difference between pressure inside and pressure outside is negligible (unless of course you live in a sealed house). So deriving barometer and altimeter using inside pressure rather than outside pressure has negligible effect. Of course if you use inside temperature

Re: [weewx-user] Re: Barometric pressure correction the right way

Tom - this has always baffled me - when the pressure reading is taken from an indoor console which is at a different temperature than outdoors. Maybe Tom knows the answer - if one carries a console from inside at 20 degrees o outside at 3 degrees does the pressure recorded on the console

RE: [weewx-user] Re: Barometric pressure correction the right way

The inside temperature does not enter the calculation. You are correcting for the weight of the air column outside, which is a function of outside density, which is a function of outside air temperature. -tk Fat-fingered from my Android On Jan 13, 2018 8:59 AM, "'ml' via weewx-user"

RE: [weewx-user] Re: Barometric pressure correction the right way

Ok i got itwith the outside temperature value 3.2°C is 1025mbar with the inside temperature 23.2°C it is 1020mbar so what is now correct air pressure is measured inside -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from

RE: [weewx-user] Re: Barometric pressure correction the right way

Have you looked at the code as Tom suggested?? On the link I gave you there is a formula for the calculation which may help Sent from Mail for Windows 10 From: 'ml' via weewx-user Sent: 13 January 2018 17:54 To: weewx-user Subject: Re: [weewx-user] Re: Barometric pressure correction the right

Re: [weewx-user] Re: Barometric pressure correction the right way

Sorry i didn't get how the barometric pressure is calculated with the temperature, altitude and absolute pressure can you help? -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it,

Re: [weewx-user] Re: Barometric pressure correction the right way

Which formula? All of the formulas used internally by weeWX are documented in the source code. In particular, look at wxformulas.py and uwxutils.py . -tk On

Re: [weewx-user] Re: Barometric pressure correction the right way

http://keisan.casio.com/exec/system/1224575267#! On Friday, 12 January 2018 19:35:01 UTC+2, ml wrote: > Can you Tell meine the Formula? So i can calculat by myself? -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group

Re: [weewx-user] Re: Barometric pressure correction the right way

Can you Tell meine the Formula? So i can calculat by myself? -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more

Re: [weewx-user] Re: Barometric pressure correction the right way

A few questions: What hardware are you using? As Andrew notes, are you use that your altitude has been set correctly? Are you sure that the other station's altitude has been set correctly? What is that altitude? Is the other station showing sea-level pressure (what weewx calls "barometer") or

Re: [weewx-user] Re: Barometric pressure correction the right way

You can change whatever formula you wish - it is open source software after all, but you will lose that change whenever weewx is updated (which is often a couple of times per year).. Simplest just to say pressure = pressure - 2 (or whatever is the difference you require) in the calibrate

RE: [weewx-user] Re: Barometric pressure correction the right way

Barometer value is calculated by Software. Can i Pick which Temperature ist used? Thanks -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to

RE: [weewx-user] Re: Barometric pressure correction the right way

if it is hardware generated the adjust barometer if you are confident the absolute pressure is correct The choice and options are all yours to pick between Sent from Mail for Windows 10 From: 'ml' via weewx-user Sent: 12 January 2018 11:49 To: weewx-user Subject: [weewx-user] Re: Barometric pressure