Barometer readings are off

http://weather.gladstonefamily.net/site/C4731

On that page it is saying that my Barometer is way off

This is one thing that the page says

There is a significant mean error in your barometer readings. You may need to calibrate your barometer. Since your readings are low, it is possible that your software is not adjusting the reading for elevation, or that your station altitude has been entered incorrectly into your software.

Being that I don’t rember entering any infomation into the altitude :oops: I think I need to do that.

So is that under Control Panel then Units/other settings???

Thanks!

That’s one of them. The first box in lower right. And another on the Sun/Moon set-up.
–Dave

[quote author=daveq link=topic=12746.msg97636#msg97636 date=1133539128]
That’s one of them.

Not sure but it can’t hurt.
–Dave

If it is still off there is a barometer off-set you can use to fine tune it to the setting you want. Have you checked it against a local airport or such? Try to find one that is close to the same elevation as you and not have a front coming though.

Maybe you are correct and the others you are being compared to are wrong. I was originally worried about my temp but when I check the metar and other info it all depends on your location. I’m not on the water as some of the stations are and they are up to 5 degrees different because of the Chesapeake or rivers they are closer to.

I use CWOP to ensure my is following the same trend not for accuracy or adjustments. But others may be more inclined to use it for that. It’s entirely up to you.

–Dave

just reset/asdjust the barometer offset under control panel, barometer offset and rainfall, that you have set there
also make sure you do not have use QFE ticked in the units setup

[quote author=daveq link=topic=12746.msg97681#msg97681 date=1133547316]
If it is still off there is a barometer off-set you can use to fine tune it to the setting you want.

It looks as though your barometer is reading low compared to LaCrosse which looks to be the closest airport to you. I’d watch it for a few days and then maybe make adjustments. Did you set your height about sea level? I can find only two places. One is Control Panel → Units/other settings and the other is Control Panel/Sun/Moon. Note that one is in feet and the other in meters.

Checking around it looks like you have your eleveation set at abut 1000 ft. and others in the area are closer to 700 ft. Are you confident in your altitude? If you want to PM me a closer address I’ll see what I can find.

–Dave

its a bit tricky comparing to an airport, as you need to compare at the same time, and you need to allow for differences due to isobars…i.e check a isobar map…

Well I changed some things around so I am going to give it a week or so to change its ways.

elevation for De Soto appears to be 690ft - is that what you have set now in WD?

Pressure for your area seems to be around the 30 inches mark but you are reading about 29.2?

cheers

Sorry about the delay been doing a 12 hour shift at work. I changed the elevation to 690ft. So what would that be in Meaters? THanks

210 meters - is the pressure reading correctly now?

Well the website still don’t like my readings but I think I am going to give it some time.

I don’t think time will help the readings - there must be a setting still set incorrectly in WD somewhere as any changes to pressure settings usually take effect straight away.

Compare the barometer reading on your Davis console to the one reported by Weather Display - are they the same or different? - is the Davis one reading about an inch more than WD?

I see that you have Davis Vantage Pro. One problem with reporting to aprs is that they are expecting the report to be altimeter readings. (adjusted for elevation only).
The VP converts to SLP.( adjusted for both elevation and temp.) When APRS gets your info they add a temp correction to it.( TO CONVERT Altimeter To SLP) As the VP has already done that it throws off the reading.Much worse in high temp times than low temps. If all else fails and you have all setting correct, then there is at this time no more that YOU can do.
Chuck

I think Chuck has given you the right answer. It is a Davis problem. I had my Davis “adjusted” until it turned cold. It doesn’t help that my inside temperature is anything but consistent! My readings are way off on the quality chart, but I’m being compared to stations 1000 meters lower than me. There just aren’t any stations showing pressure anywhere close to me to compare to. I’ve temporarily given up.

There is another VP station 1/2 mile from me. same elevation same side of the mountain. He has readings same as mine and he gets red flaged when it is hot.Same as I do.
Chuck

This has been discussed in the CWOP Quality Control mailings and supposedly Dave and Russ are going to bring this up with Davis as it appears to be related, as indicated above, to the method the VP reports barometric pressure to CWOP…

There has been quite a few VP users (not sure what software they are running) that have gotten zinged in the QC reports as a result from what i have read in the mailings…

-Bob

Which brings up another question. Isn’t it the software (WD, or the Davis program) that is doing the actual reporting to CWOP? Would it possible to have WD convert the pressure reading back to alt for the data upload? I’m not sure how Davis would fix this other than to alter their software. I don’t think the counsel has a flash ram. Or am I completely confused?