Author Topic: VP2 temperature sensors off  (Read 1454 times)

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Offline PaulMy

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Re: VP2 temperature sensors off
« Reply #25 on: June 12, 2018, 09:58:28 AM »
Quote
<blockquote>Which leads to the question - what's the similar temperature situation with the new WiFiLogger?
</blockquote>
Worth asking, but here again, the normal 'use case' would have it continuously powered.
I have Envoy/USB with VVP running Weatherlink and Cumulus and also a Vue/WiFiLogger (backlight not on) both connected to power outlet and also with batteries installed.

They are located in the identical location and after several minutes of comparing indoor temp the
Envoy/USB had temps of 24.7°C - 24.9°C - 24.9°C - 25.1°C - 25.2°C
WiFiLogger had temps of 27.1°C - 26.9°C - 27.0°C - 27.1°C - 26.6°C
so the difference between the two is from 1.6°C to 2.4°C higher for the Vue/WiFiLogger.

The outdoor temp was the same for all as it should coming from the same ISS.

Enjoy,
Paul



 

Offline pfletch101

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Re: VP2 temperature sensors off
« Reply #26 on: June 12, 2018, 10:17:50 AM »
I have Envoy/USB with VVP running Weatherlink and Cumulus and also a Vue/WiFiLogger (backlight not on) both connected to power outlet and also with batteries installed.

They are located in the identical location and after several minutes of comparing indoor temp the
Envoy/USB had temps of 24.7°C - 24.9°C - 24.9°C - 25.1°C - 25.2°C
WiFiLogger had temps of 27.1°C - 26.9°C - 27.0°C - 27.1°C - 26.6°C
so the difference between the two is from 1.6°C to 2.4°C higher for the Vue/WiFiLogger.

Very useful information! It would also be nice to know whether the offset changes over time depending on the 'activity' of the logger and/or on the actual ambient temperature.
Vantage Pro 2+ connected to Raspberry Pi running weewx by means of Meteo-Pi - data incorporated in domestic energy production (PV) and use monitoring system.

Offline dalecoy

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Re: VP2 temperature sensors off
« Reply #27 on: June 12, 2018, 12:43:14 PM »
I have Envoy/USB with VVP running Weatherlink and Cumulus and also a Vue/WiFiLogger (backlight not on) both connected to power outlet and also with batteries installed.

They are located in the identical location and after several minutes of comparing indoor temp the
Envoy/USB had temps of 24.7°C - 24.9°C - 24.9°C - 25.1°C - 25.2°C
WiFiLogger had temps of 27.1°C - 26.9°C - 27.0°C - 27.1°C - 26.6°C
so the difference between the two is from 1.6°C to 2.4°C higher for the Vue/WiFiLogger.

Very useful information! It would also be nice to know whether the offset changes over time depending on the 'activity' of the logger and/or on the actual ambient temperature.

By your definition, this is a "serious design flaw" in the WiFiLogger.  However, I can't think of an in-console design with those capabilities that would not have this "serious design flaw".

Offline PaulMy

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Re: VP2 temperature sensors off
« Reply #28 on: June 12, 2018, 01:27:03 PM »
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Very useful information! It would also be nice to know whether the offset changes over time depending on the 'activity' of the logger and/or on the actual ambient temperature.
I've done a further more precise check and
From 12:50:00 to 13:07:01 the Envoy/USB has been 26.3°C and the WiFiLogger mostly 26.6°C and twice 26.7°C so very close to each other this time.
I presume the Envoy/USB is being polled by VVP every few seconds and I can see the time and temp in Cumulus/Weatherlink.

The WiFiLogger realtime data screen updates every 5 seconds, except at the 5 min the realtime data screen does not update for about 2 minutes.  At this 5 min upload interval WiFiLogger begins to FTP the 5 day logger data to my website (about 170,000 file size), and uploading WL, WU, PWS, CWOP, AWEKAS, WOW and one other.  During this 2 min delay the indoor temp display does not change nor is there any change when the realtime data screen begins its new 5 sec updates so presume the indoor temp has not changed during that delay period.

Not sure why earlier there was about a 2°C difference and now nearly identical.  Nothing has changed other than a couple of hours later. 

I have been on this computer for the whole time doing other stuff.

I hope I have been clear enough.Paul
« Last Edit: June 12, 2018, 01:30:18 PM by PaulMy »

Offline pfletch101

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Re: VP2 temperature sensors off
« Reply #29 on: June 12, 2018, 01:42:33 PM »
I have Envoy/USB with VVP running Weatherlink and Cumulus and also a Vue/WiFiLogger (backlight not on) both connected to power outlet and also with batteries installed.

They are located in the identical location and after several minutes of comparing indoor temp the
Envoy/USB had temps of 24.7°C - 24.9°C - 24.9°C - 25.1°C - 25.2°C
WiFiLogger had temps of 27.1°C - 26.9°C - 27.0°C - 27.1°C - 26.6°C
so the difference between the two is from 1.6°C to 2.4°C higher for the Vue/WiFiLogger.

Very useful information! It would also be nice to know whether the offset changes over time depending on the 'activity' of the logger and/or on the actual ambient temperature.

By your definition, this is a "serious design flaw" in the WiFiLogger.  However, I can't think of an in-console design with those capabilities that would not have this "serious design flaw".

I think that it is a significant problem, and certainly one that one needs to know about, and I find it worrying that Paul is now not seeing the previous discrepancy, since this might suggest that the effect is variable, and so could not be fixed by a simple offset. I regard the USB logger's problem as much more serious because that device is much more likely to be used in a way that makes it impossible to ameliorate the issue by any simple action (such as setting a fixed offset) - i.e. in an application such as mine where the attached computer is switched off overnight. As I have implied, devices with a direct IP connection are likely to be used specifically because a 24/7 connection is needed, making potential amelioration of the issue easier.
As I have said elsewhere, IMHO, the right answer is to have (at least as an option) the indoor TH sensor outside the enclosure of the console, or at least better isolated from potentially heat-producing accessories. The design flaw is at least as much in the console layout as in the loggers.
Vantage Pro 2+ connected to Raspberry Pi running weewx by means of Meteo-Pi - data incorporated in domestic energy production (PV) and use monitoring system.

Offline stromb0li

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Re: VP2 temperature sensors off
« Reply #30 on: June 12, 2018, 06:44:31 PM »
Is there documentation on how to use an external indoor temperature sensor with the console?  I have a HTU21D-F Temp/Humidity sensor, which seems to be with +-1F of the outdoor sensor that might be a good alternative for the console.