Topic: pressure reading ??

[oleweatherfan]

why is my pressure reading way off from other nearby stations thats within a mile from me?? My 14 day learning is not quite over yet could that be the reason? or is it still likely to be off that much even when thats done?

[William Grimsley]

Hi there,

I don't own an Acurite but how bad is the difference?

Will

[SLOweather]

There should be somewhere in the setup a way to enter your elevation above sea level to correct the baro. Did you, and are you confident in your number?

[oleweatherfan]

my readings are off from theirs by 15 points. Also their is no way to set the Baro on the 1010 model it says it goes through a 14 day learning period and calculates alt and other things.

[oleweatherfan]

right now the other station near me is reading 29.91 and im reading 29.71 so right now thats 20 pts difference!

[kc4sbd]

    I have 2 Acu-Rite displays on the same ISS 5 in 1 sensor one is a 01500 and the other 01025 one is reading 29.80 and the other is 29.88, I also have the Acu-Rite 02036 display with the tower sensor 609txc and the display (which I am beta testing for Acu-Rite this unit at the present time) is reading 30.04, my 5in1 is in the back yard and my 609 is in the front yard about 300 feet away from each other, I cant answer the question but I bet if you had 100 of the same setups they all would be different, just my experience in weather monitoring says every point on the earth is different and every display and ISS is different, if your readings were 2-3 points in difference (but your is tenths not whole numbers) I would probably say you needed to calibrate or replace the unit but wait till after the 14 day learning period is over and see what happens, I actually went through 2 -14 day learning periods with both my units..... hope this helps  

[Weather Display]

you could always restart the 14 day learning period when there is likely to be a nice period of high then low barometer reading

[vreihen]

my 5in1 is in the back yard and my 609 is in the front yard about 300 feet away from each other,

For what it's worth, the barometer is not in the 5-in-1 outdoor sensor, but rather in each console.  The bridge also supposedly contains it's own barometer.

I also seem to recall reading somewhere that the best results from the learning period are to start it when the real pressure is 29.92 (or was it 29.96?).  Might be worth a search of this forum or AcuRite's support forum for the specific posting.....

[oleweatherfan]

Well the 14 day learning is complete and nothing has changed. What's confusing is during they day when the humidity is low the baro reads high the icon shows sun and cloud. Then at night the humidity rises and the baro will drop and the icon will show clouds and rain it does this every single day and night!

[Weather Display]

there is a diuranal barometer change
but that is normaly a baro drop during the day (warmer air is lighter) and baro rise at night (colder air is more dense-> heavier)

[oleweatherfan]

there is a diuranal barometer change
but that is normaly a baro drop during the day (warmer air is lighter) and baro rise at night (colder air is more dense-> heavier)

Mine is dropping at night and rising during the day by 20 pts difference. Also the station I'm comparing to approx 1 mile away was showing a higher humidity than me so I reset my 14 day and calibrated my humidity with theirs and see what that does. Everything else is dead spot on with them and that's at airport so they should be pretty accurate. The only different from mine and theirs was the baro (20pts difference) and the humidity (10% difference)

[DanS]

First off, your baro readings and humidity readings are two separate and unrelated issues. With regard to your barometer readings, is there any possibility yours may be right and the other station you're comparing to is slightly off? I've caught times where the International (METAR reporting station) airport 1/2 mile from here has had some minor "tweaking" needed here and there, so it's a possibility.

Now, totally unrelated, your humidity readings should not even be compared with a station a mile away, maybe 10 feet away at the most. If you have a trusted hygrometer that you could place next to your 1010 outdoor sensor to compare with, this would be a lot better. Humidity, like temps, wind, and rain can vary greatly in very short distances.

[Rhino]

First off, your baro readings and humidity readings are two separate and unrelated issues. With regard to your barometer readings, is there any possibility yours may be right and the other station you're comparing to is slightly off? I've caught times where the International (METAR reporting station) airport 1/2 mile from here has had some minor "tweaking" needed here and there, so it's a possibility.

Now, totally unrelated, your humidity readings should not even be compared with a station a mile away, maybe 10 feet away at the most. If you have a trusted hygrometer that you could place next to your 1010 outdoor sensor to compare with, this would be a lot better. Humidity, like temps, wind, and rain can vary greatly in very short distances.

I couldn't agree more with this statement- especially about humidity. I would actually take it a bit further- in our test chamber, we see slight humidity differences within inches- and that is in as controlled as an environment as you can hope for. Also, note that there can be variances in pressure due to geographic location differences of course, but less often realized- the little differences in the pressure sensor itself will manifest itself as variations. That is why we are continuing to build in manual adjustment capabilities into our weather stations, they will all track the changes great, but the number may be slightly off. The adjustment option allows you to bring it in to line with a source close to you if you wish to.

[oleweatherfan]

First off, your baro readings and humidity readings are two separate and unrelated issues. With regard to your barometer readings, is there any possibility yours may be right and the other station you're comparing to is slightly off? I've caught times where the International (METAR reporting station) airport 1/2 mile from here has had some minor "tweaking" needed here and there, so it's a possibility.

Now, totally unrelated, your humidity readings should not even be compared with a station a mile away, maybe 10 feet away at the most. If you have a trusted hygrometer that you could place next to your 1010 outdoor sensor to compare with, this would be a lot better. Humidity, like temps, wind, and rain can vary greatly in very short distances.

I couldn't agree more with this statement- especially about humidity. I would actually take it a bit further- in our test chamber, we see slight humidity differences within inches- and that is in as controlled as an environment as you can hope for. Also, note that there can be variances in pressure due to geographic location differences of course, but less often realized- the little differences in the pressure sensor itself will manifest itself as variations. That is why we are continuing to build in manual adjustment capabilities into our weather stations, they will all track the changes great, but the number may be slightly off. The adjustment option allows you to bring it in to line with a source close to you if you wish to.

The thing that gets me here though is that every night it shows that there is rain in the forecast when there is not even a system in sight of 10 days! And the reason it's shows that is the pressure drops drastically and there is no way that is right. I've reset the 14 day to see if that hopefully fixes the problem!

[DanS]

I keep reading this thread over beginning to end and believe I'm starting to see what may be happening. First, an assumption on my part is that Acu-rite uses the barometric readings (at least) to generate the forecast icons regardless of what's actually happening outside at the present or near future. Similar to the old forecast saying, dropping pressure=stormy weather approaching, rising pressure=expect clearing, etc. Other wx stations use the barometer this way for their forecast icons too. Certain times of the year here I see my stations doing this, show cloudy and/or rain and there isn't a cloud around. This was because the pressure took a dive. During our rainy/monsoon season this works pretty accurately but during our 5-6 month dry season I ignore it.  So, if this is the case I'd recommend just ignoring the forecast portion for now and concentrate on your actual barometric readings. Compare every couple waking hours to your local wx radio/tv station's barometric readings. You may find out that yours is actually tracking correctly with the nightly drops and daily rises. Or even watch the station you compare to a mile away, even if you are "20 points" different do you both rise and fall the same?

[oleweatherfan]

Ok example right now my pressure is dropping went down 6 points to 29.86 and the right baro is is 30.13 and steady from my local NOAA. Just isn't making any since at all to me! 

[DanS]

Ok example right now my pressure is dropping went down 6 points to 29.86 and the right baro is is 30.13 and steady from my local NOAA. Just isn't making any since at all to me! 

While your 1010 is dropping and your NOAA is staying steady, what's the station 1 mile away doing? Staying steady as well or dropping? It's good you have a couple references to compare to.

[oleweatherfan]

Ok example right now my pressure is dropping went down 6 points to 29.86 and the right baro is is 30.13 and steady from my local NOAA. Just isn't making any since at all to me! 

While your 1010 is dropping and your NOAA is staying steady, what's the station 1 mile away doing? Staying steady as well or dropping? It's good you have a couple references to compare to.

Steady and reading within 2 points of NOAA

[DanS]

That's a real head scratcher for sure. 3 barometers, 2 staying steady and one cycling down.? Even if it were a defective baro sensor what would cause it to cycle/change while the pressure remains steady.... (thinking out loud here)  I'm obviously missing something here.

[vreihen]

Once I got the pressure adjusted in MBW, my barometer has been tracking within 0.01 inch against the ASOS about 4 miles across town.  It does occasionally record an insane spike, like the 55.53 inches it saw in the evening on 10/16 that set off a storm alert e-mail in the middle of dinner when it returned to normal.....

[Weather Display]

is the indoor temperature changing when the pressure changes?
i.e sounds like it might not be temperature compensated

[William Grimsley]

my readings are off from theirs by 15 points. Also their is no way to set the Baro on the 1010 model it says it goes through a 14 day learning period and calculates alt and other things.

15 points! Yes, thats a big problem!

[oleweatherfan]

is the indoor temperature changing when the pressure changes?
i.e sounds like it might not be temperature compensated

Yes it seems that the inside temp will go down a couple degrees when the baro goes down

[oleweatherfan]

is the indoor temperature changing when the pressure changes?
i.e sounds like it might not be temperature compensated

Yes it seems that the inside temp will go down a couple degrees when the baro goes down

No sorry I got that wrong when the indoor temp is low the pressure is high and when temp is higher the pressure is lower

[oleweatherfan]

Once the bridge comes out and I get online will I be able to adjust the pressure in MBW to my local stations pressure? If I can do that then I'm not gonna worry to much about what it's doing now I will just wait till I get the new bridge. If it ever comes out!