Topic: Atlas HD Display Dewpoint

[Mirwin275]

I don't know why my display says a dewpoint of 67 when my temperature is 69.4 with 100% humidity. To my knowledge, I always thought the dewpoint should match the temperature if the humidity is 100%. I have not set a calibration in any way with the display. That is the way I always have seen it calculated. The dewpoint matching means the air is fully saturated with moisture. Any thoughts or have noticed the same thing with the Atlas display? [ You are not allowed to view attachments ]

[galfert]

Might be related to the console doing some poor rounding of temperatures as has been reported in this forum.

And it could all be associated with how the product was designed to report averages instead of live data. But don't quote me on that.

[Mirwin275]

Might be related to the console doing some poor rounding of temperatures as has been reported in this forum.

Could be, since the temperature rounds weird on the display. I am aware of the temperature rounding issue.

[worachj]

Add me to its a display rounding issue. 

Check your display’s SD card data and Weather Underground site if you have them. The SD card data and WU seem correct.  The temp/dew points on Weather Underground’s history graphs match for my station when it was reporting 100% humidity. And the data on the SD card seems correct to me.

[Neil_O]

I don't know why my display says a dewpoint of 67 when my temperature is 69.4 with 100% humidity. To my knowledge, I always thought the dewpoint should match the temperature if the humidity is 100%. I have not set a calibration in any way with the display. That is the way I always have seen it calculated. The dewpoint matching means the air is fully saturated with moisture. Any thoughts or have noticed the same thing with the Atlas display? [ You are not allowed to view attachments ]

I have noticed exactly the same phenomenon on the Atlas HD display that I have.  From memory, I think the numbers on Weather Underground are exactly the same (but will need to confirm).  This issue only seems to last about 15-20 minutes in the morning after a very-humid (100% humidity) night.

I'll be interested in the final diagnosis.

[worachj]

Here's the historical records for my stations data from WU on Oct 3rd, 2018. Dew point matches temp when there's 100% humidity. Not sure what the HD display was showing at the corresponding time.

Change to data view and scroll thru historical data until you find 100% humidity readings and look at Dew point and Temp.
https://www.wunderground.com/personal-weather-station/dashboard?ID=KMNSAINT173#history/s20181003/e20181003/mdaily

[worachj]

Here's the corresponding data from my HD Display's SD card showing Temp different than Dew point when there's 100% humidity. There's a Dew point calculation problem on the HD Display:

     Date              time   Temp Humd  Dew point

Code: [Select]

20181003 4:51:40 55.9 100 55
20181003 4:51:50 55.9 100 55
20181003 4:52:00 55.9 100 55
20181003 4:52:10 55.9 100 55
20181003 4:52:20 56.1 100 55
20181003 4:52:30 56.1 100 55
20181003 4:52:40 56.1 100 55
20181003 4:52:50 55.9 100 55
20181003 4:53:00 55.9 100 55
20181003 4:53:10 55.9 100 55
20181003 4:53:20 56 100 55
20181003 4:53:30 56 100 55
20181003 4:53:40 56 100 55
20181003 4:53:50 56 100 55
20181003 4:54:00 56 100 55
20181003 4:54:10 56 100 55
20181003 4:54:20 56 100 55
20181003 4:54:30 56 100 55
20181003 4:54:40 56 100 55
20181003 4:54:50 55.9 100 55
20181003 4:55:00 55.9 100 55
20181003 4:55:10 55.9 100 55
20181003 4:55:20 55.9 100 55
20181003 4:55:30 56.1 100 55
20181003 4:55:40 56.1 100 55
20181003 4:55:50 56.1 100 55
20181003 4:56:00 56 100 55
20181003 4:56:10 56 100 55
20181003 4:56:20 56 100 55
20181003 4:56:30 56 100 55
20181003 4:56:40 56 100 55
20181003 4:56:50 56 100 55
20181003 4:57:00 56 100 55
20181003 4:57:10 56 100 55
20181003 4:57:20 56 100 55
20181003 4:57:30 56 100 55
20181003 4:57:40 56 100 55
20181003 4:57:50 56 100 55
20181003 4:58:00 56.2 100 55
20181003 4:58:10 56.2 100 55
20181003 4:58:20 56.2 100 55
20181003 4:58:30 56 100 55
20181003 4:58:40 56 100 55
20181003 4:58:50 56 100 55
20181003 4:59:00 56.1 100 55
20181003 4:59:10 56.1 100 55
20181003 4:59:20 56.1 100 55
20181003 4:59:30 56.1 100 55
20181003 4:59:40 56.1 100 55
20181003 4:59:50 56.1 100 55
20181003 5:00:00 56.1 100 55
20181003 5:00:10 56.1 100 55
20181003 5:00:20 56.1 100 55
20181003 5:00:30 56.1 100 55
20181003 5:00:40 56.1 100 55
20181003 5:00:50 56.1 100 55
20181003 5:01:00 56 100 55
20181003 5:01:10 56 100 55
20181003 5:01:20 56 100 55
20181003 5:01:30 56.1 100 55
20181003 5:01:40 56.1 100 55
20181003 5:01:50 56.1 100 55
20181003 5:02:00 56 100 55
20181003 5:02:10 56 100 55
20181003 5:02:20 56 100 55
20181003 5:02:30 56 100 55
20181003 5:02:40 56.1 100 55
20181003 5:02:50 56.1 100 55
20181003 5:03:00 56.1 100 55
20181003 5:03:10 56 100 55
20181003 5:03:20 56 100 55
20181003 5:03:30 56 100 55
20181003 5:03:40 56.2 100 55
20181003 5:03:50 56.2 100 55
20181003 5:04:00 56.2 100 55
20181003 5:04:10 56.1 100 55
20181003 5:04:20 56.1 100 55
20181003 5:04:30 56.1 100 55
20181003 5:04:40 56.1 100 55
20181003 5:04:50 56.1 100 55
20181003 5:05:00 56.1 100 55
20181003 5:05:10 56.1 100 55
20181003 5:05:20 56.1 100 55
20181003 5:05:30 56.1 100 55
20181003 5:05:40 56.1 100 55
20181003 5:05:50 56.1 100 55
20181003 5:06:00 56.1 100 55
20181003 5:06:10 56.2 100 55
20181003 5:06:20 56.2 100 55
20181003 5:06:30 56.2 100 55
20181003 5:06:40 56.1 100 55
20181003 5:06:50 56.1 100 55
20181003 5:07:00 56.1 100 55
20181003 5:07:10 56.1 100 55
20181003 5:07:20 56.1 100 55
20181003 5:07:30 56.1 100 55
20181003 5:07:40 56.2 100 55
20181003 5:07:50 56.2 100 55
20181003 5:08:00 56.2 100 55
20181003 5:08:10 56.1 100 55
20181003 5:08:20 56.1 100 55
20181003 5:08:30 56.1 100 55
20181003 5:08:40 56.1 100 55
20181003 5:08:50 56.1 100 55
20181003 5:09:00 56.1 100 55
20181003 5:09:10 56.1 100 55
20181003 5:09:20 56.2 100 55
20181003 5:09:30 56.2 100 55
20181003 5:09:40 56.2 100 55
20181003 5:09:50 56.2 100 55
20181003 5:10:00 56.2 100 55
20181003 5:10:10 56.2 100 55
20181003 5:10:20 56.2 100 55
20181003 5:10:30 56.2 100 55
20181003 5:10:40 56.2 100 55
20181003 5:10:50 56.2 100 55
20181003 5:11:00 56.2 100 55
20181003 5:11:10 56.2 100 55
20181003 5:11:20 56.2 100 55
20181003 5:11:30 56.2 100 55
20181003 5:11:40 56.2 100 55
20181003 5:11:50 56.2 100 55
20181003 5:12:00 56.2 100 55
20181003 5:12:10 56.2 100 55
20181003 5:12:20 56.1 100 55
20181003 5:12:30 56.1 100 55
20181003 5:12:40 56.1 100 55

[radioman61]

I really hope the SD card slot can also be used for software updates as Acurite works through some of these bugs...

[worachj]

I really hope the SD card slot can also be used for software updates as Acurite works through some of these bugs...

Same here! I want to buy a 2nd HD display but hate the errors and the way it displays rain totals. I don't know who likes the rolling rain totals that go from 24hr, 48hr and then 72 hrs. All I want to do is look at the display and see the days total. Please just display zero if there's been no rain. Because of the rolling total I've actual seen the rain total decrease as it was raining outside.

[yankeesdood16]

The dew point on the display is always a degree or two lower than on myacurite(the app).   With 100% humidity the temp and dew point always match on the app, so yea it’s a rounding issue on the display.