High resolution display 06058 pressure calibration

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  • Updated 6 months ago
  • (Edited)
Barometric pressure needs to be adjusted for station elevation. I am at about 175' above MSL.  Local airport about 2 miles away shows pressure at 30.06 mmHg, but I can only calibrate mine +0.1 mmHg upward giving a reading of 29.87.  A little wider adjustment range would be nice.  Certainly not a professional weather station but it is what it is.  Guess the trend is more what you are interested in.
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Miwalk

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Posted 7 months ago

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AcuRite Rachell, Employee

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Hello Miwak,

If your barometric pressure is reading inaccurately, we would recommend restarting your learning mode.  To restart your learning mode, enter display menu by pressing the gear button all the way on the left then arrow down to Factory Reset in the Menu settings. Change the next option to "YES" then the display will tell you to press the "Check mark" twice. Please let us know if this issue continues. Thank you. 
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Miwalk

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That helped.  Had to calibrate -0.10 this time but it is right on now. I'll check it for a few days and see how it compares.
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AcuRite Jennifer

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Hello Miwalk,

Please let us know if you continue to experience an issue. Have a great weekend!
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Miwalk

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Calibration didn't last long.  Pressure at airport has been 30.19-30.20 all morning, but at +0.10 I can only calibrate to 30.01.  Guess I'll live with it, not going to reset to factory settings every couple of days.
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George D. Nincehelser

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Have you let the learning period finish before calibrating?
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AcuRite Tori

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Hello Miwalk,

George has brought up a good point. Have you completed the  learning mode? Resetting the display every couple of days will restart the learning mode. Which will affect the barometric pressure reading that you are receiving on the display console.
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AcuRite Tori

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Hello Miwalk,

George has brought up a good point. Have you completed the  learning mode? Resetting the display every couple of days will restart the learning mode. Which will affect the barometric pressure reading that you are receiving on the display console.
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Miwalk

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I read that but thought it related only to the forecast.  Guess I'll have to wait 10 more days to see since I reset factory settings.  Do I need to set the offset I have now back to 0.00?

Thanks all.
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AcuRite Rachell, Employee

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Hello Miwalk,

The display's learning mode is the display learning your elevation to provide an accurate barometric pressure and forecasting.  We would recommend to wait the full learning mode before applying calibrations.  Thank you.
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Miwalk

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Thanks for the information on the learning mode.  It is getting close now, well within the calibration offset range of the display.  I'll let it run awhile longer before trying any final calibration.
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AcuRite Jennifer

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Hello Miwalk,

Please let us know if it adjusts correctly once the learning mode is complete. Did you remove the calibrations?
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Miwalk

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Yes.
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AcuRite Rachell, Employee

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Hello Miwalk,

Thank you for this information. Please let us know your readings once your learning mode is complete. Thank you.
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Miwalk

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Thought it was getting better, but guess not.  After allowing for learning mode, local airport shows 30.06, another airport 15 miles away shows 30.07.  My display shows 29.01 so I'm still outside the maximum calibration range which at +0.10 would be 30.01.  That is still only 0.05 off with the offset, so I'll keep checking it.
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AcuRite Rachell, Employee

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Hello Miwalk,

Did you wait the full 33 days before applying the calibration?  Please wait the full 14-33 days before calibrating the barometric pressure on the display unit.  We recommended to restart the learning mode on Oct 26th.  This is not a full 33 days.  If the display was restarted on October 26th then 33 days will be Nov 28th or 29th.  Please wait for an accurate pressure reading. Thank you.


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Miwalk

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The original information and the manual states 14 days, not 33 days.  I don't know where the 33 days comes from.  If that is what is required, it should be stated in the manual for the unit.
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George D. Nincehelser

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14 days is when the learning icon turns off and the pressure reading is generally good enough for forecasting purposes.

However, the algorithm keeps running to 33 days for further fine-tuning.
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AcuRite Jennifer

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Hello Miwalk,

George is correct. There is a learning mode icon that will come on the display for 14 days. It is the learning mode icon. Once this is complete you should see a complete forecast and pressure reading. The display will continue to the learning mode for a total of 33 days. Once that is done the learning mode is complete. 
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Miwalk

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How in the world would anyone know that from the information presented in the manual for the unit?  I'm not going to reset it to factory default and start over again.  If it is always off by -0.05 at a maximum calibration offset, then so be it.  A calibration offset shouldn't matter if it is still learning except that you may eventually end up with a high reading.  I will continue to monitor it's accuracy until 12-01.
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AcuRite Rachell, Employee

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Hello Miwalk,

I do apologize if the manual did not explain properly.  In the area where it explains the learning mode, you are correct, it only says 14 days. Lower in the manual under troubleshooting it says:

• Weather Forecast icon predicts conditions for the next 12 to 24 hours, not current conditions.


• Allow product to run continuously for 33 days.  Powering down or resetting the display will restart Learning Mode. After 14 days, forecast should be fairly accurate, however Learning Mode calibrates for a total of 33 days.



We will certainly keep this is mind for possible future updates to the manual.  Please let us know what you read for barometric pressure after 12/1. Thank you.
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Miwalk

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Well, here we are on December 1, 2017. It has been over 33 days now.  With the maximum calibration offset of +0.10, the pressure reading has been and continues to be 0.05 low.  This has been very consistent over this period and I don't guess it will automatically adjust further.  It is what it is.  I guess a 0.05 in Hg error isn't too bad.
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AcuRite Jennifer

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Hello Miwalk,

When you are going through the learning mode we do not recommend entering any calibrations on the weather station for the pressure. You would want to restart the display when your local pressure is at 29.92. Once that is done let it complete the learning mode. Once the learning mode is complete if the pressure is off then apply the calibrations.
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Miwalk

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This is getting ridiculous.  Why would I want to restart the display when the local pressure is exactly 29.92?  This isn't stated anywhere in the manual so no one would ever know of this requirement.  It would be virtually impossible to do unless you sat by the monitor continuously.

Although you don't publish the accuracy tolerance for the sensors, my pressure sensor appears to have a tolerance of about + or - 1%, which isn't bad.  The display just needs a calibration range a little wider than + or - 0.10.

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George D. Nincehelser

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Starting at 29.92 is not necessary.  Thar averaging  of math  will take care of itself in most cases.  it will make the  sways in pressure less noticeable, and it might look to make the process speed up, but that's not important.  Just let it tun through the complete learning period of 33 days, not just the two weeks.  By then all auto adjustment is done. manual adjustment is the easier to do.
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Miwalk

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I took the calibration offset out while I let it run 33 days.  Although it was initially applied, I removed it after I was informed of the 33 day requirement.  It made no difference.  In my post I added the +0.10 offset to see if I could get to a present reading at the local airport.  Doesn't make any difference after 33 days.  It always reads 0.15 low without any offset, or 0.05 low with maximum offset.
(Edited)
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Miwalk

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Just saying, if the sensor tolerance is 1% and the pressure is 30.00, the calibration offset should be at least + or - 0.30 to cover the tolerance of the sensor.  30 x 0.01 =0.30.
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George D. Nincehelser

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The published  accuracy of Acurite's digital products is actually +/- 0.15 inHg after learning mode is completed.  So it sounds like you're just at the edge of spec without any manual offset.

https://www.acurite.com/learn/accuracy
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AcuRite Rachell, Employee

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Hello Miwalk,

As George stated above, the accuracy range will be within +/-0.15inHg (+/- 5mbar). For instance, if the current relative air pressure is 29.92inHg, then the unit could read within the range of 29.77inHg to 30.07inHg.  The accuracy for temperature and humidity is +/-2° and 5% per unit.  We only recommend restarting your learning mode when the local barometric pressure is at 29.92 when you are having trouble getting an accurate forecast or barometric pressure reading after restarting the learning mode. This can help the learning mode provide accurate readings.
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Miwalk

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If it can be off by +/- 0.15, then the calibration range should be at least +/- 0.15. 
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AcuRite Jennifer

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Hello Miwalk,

The display will only let you calibrate +/- 10.  It is the way the product was designed. What is your pressure currently reading without calibrations once the learning mode is complete, and what do you think it should be reading?
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Miwalk

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My pressure reading is 30.07 with no calibration offset.  With max calibration offset of +0.10 it shows 30.17.  Pressure at the airport 2 miles away is 30.22.  Therefore it is has been 0.05 consistently low with maximum calibration offset.  I realize it is designed for a maximum offset of +/- 0.10.  Seems like a poor design if the sensor tolerance is +/-0.15 and a calibration range of +/-0.10 won't cover the tolerance range.
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George D. Nincehelser

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Actually, that's not the tolerance of the sensor.  It's just what Acurite is going to guarantee for their digital barometer products in general.  The actual hardware sensor tolerance is going to be tighter than that, and the actual hardware sensor itself may vary from model to model.

The calibration is actually there to compensate for what statistical error there might be from the "learning period" algorithm.  If you re-started the learning period, chances are you'll fall better within the calibration limits they chose.

Acurite used to publish the formula used for the "learning period" in their early spec sheets.  Unfortunately I don't have one handy.  The formula is interesting in that it actually eliminates any consistent error due to the hardware itself... that kind of error washes out in the math.

What "error" you are left with is generally due to unusual pressure patterns that didn't happen to average out over the 33-day period.  Typically 33 days is good enough, but if you happened to be locked into a extended high or low period, it could throw off the calculated average.  I suppose hurricane season could also throw off the average, too.
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Miwalk

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I appreciate the information.  Doesn't really tell me much.  I haven't seen any unusual pressure patterns since I restarted the learning mode, but guess some could have occurred. Hurricane season is over so there haven't been any hurricanes or extreme lows that I have seen.   I guess I'll just accept the fact that it is always 0.05 low and live with it since that has been very consistent.  Seems like if Acurite guarantees +/- 0.15 they would have made the calibration range +/- 0.15 to compensate.