Topic: Davis 6830 temperature/humidity station sensor resolution

[guym55]

Hi all,

My first post  !

After setting up a Davis VP2+ with a daytime aspirated fan on my roof, I was curious as to the temperature differences with a sensor set 1m above ground (short grass).  The ISS is set up about 1.5m above an angled cement tiled roof (very common in Australia).  We are getting into warmer weather, so I expected the ISS to still suffer from radiated heat from the roof tiles in daytime hours.

I purchased a Davis 6830 temperature/humidity station and set it up in my backyard (bang in the middle, 2m metal fencing on 3 sides and a brick wall on the 4th, all at least 4m from the station).

The outcome is that the ground station shows warmer temperatures in daylight and is cooler at night, however the sensor seems to be of inferior quality to the one in the iSS - see the attached graph - temp2 - ground station, is very blocky (temp changes seem to be in 0.5c increments;) temp1- ISS on roof, is more responsive (reacts to 0.1c).

Am am correct that it is a sensor resolution issue rather than a setting issue?  The ground station is wireless, using the Davis anemometer transmitter kit.  Either way I welcome comments, etc.

Thank you all in advance

Guy

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[johnd]

1. Your graph image (or whatever it is) is not showing up legibly.

2. 6830 is just a Temp/Hum sensor and not a station. I'm guessing you mean that the 6830 is cabled to a 6332 Anemometer Transmitter and being received at the console as a Temp/Hum station on whatever channel the 6332 is set to. Correct?

3. Assuming so, then yes - as the Davis documentation says - all supplementary temperature readings can only be received to a resolution of 1F (ca 0.5C) on a standard console, unless received on eg an Envoy8X or Meteobridge Pro unit. This is a well-documented limitation of the standard console.

[Mattk]

in any case even though the resolution may be 0.1c the accuracy is +/- 0.5c

[nixxon]

"...6830 is [...] not a station..."

Talking about real stations, here are some big stations:

http://en.rocketnews24.com/2013/01/30/the-51-busiest-train-stations-in-the-world-all-but-6-located-in-japan/

According to the 6830 User Manual* page 5, the resolution is user selectable, 0.1 F or 0.1 C

*7395.344 Rev. A 1/8/16

It seems the Aussie bloke wants higher resolution and not better accuracy.

[johnd]

According to the 6830 User Manual* page 5, the resolution is user selectable, 0.1 F or 0.1 C

*7395.344 Rev. A 1/8/16

No, that's only relevant when the 6830 is being received as the primary T/H sensor (on the standard console) which is not the case here. When it's a supplementary T/H, the received measurement resolution is 1F.

It seems the Aussie bloke wants higher resolution and not better accuracy.

I wonder if he didn't read the specs carefully enough before purchasing. Actually I think that the intrinsic sensor accuracy is typically better than 1F  - 0.4F would be my estimate - but 1F is all that's promised (fsvo 'promised').