Author Topic: WS-2080 temperature accuracy  (Read 11842 times)

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Offline raedh

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WS-2080 temperature accuracy
« on: July 24, 2012, 05:45:04 AM »
I've installed ws-2080 with SRS100LX  on rooftop (concrete) siting location is 900m asl , the wind sensors 4m above ground , the temperature 1.25m above ground everything running good, one of our private weather companies connect the station to its network where the nearest station 10 km far from my station at 940m asl (davis pro),  I noticed there is a weird trend , in the daytime my site at 900m asl record temperatures less than the station in 940m by 1.3 degree , but in the night time vice versa , for example


WS-2080 Station (900asl) : max : 33c      ,    min: 25.2c
davis pro station (940asl)  : max : 34.2c   ,    min : 23.8c

and so on for other days, is there any logical explanation of this behaviours , is it ws-2080 problem or what?

station link : http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=IMARIKHA2

Thanks

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #1 on: July 24, 2012, 05:58:40 AM »
First thing is the 10km distance is quite far and micro climates are to be considered. Another thing is the fact that your SRS100LX is mounted above concrete and may be giving you a lesser temperature swing (high to low) than the station you are comparing to if that one is mounted in a better environment, 2 meters above open grassy area.
« Last Edit: July 24, 2012, 06:01:31 AM by DanS »

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #2 on: July 24, 2012, 06:09:43 AM »
so what do you advice DanS because the rooftop is the only site i can mount the station

Thanks

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #3 on: July 24, 2012, 06:25:20 AM »
Maybe place the SRS100LX a little higher away from the concrete if possible?  Concrete retains and radiates temperature / takes longer to change (cool down at night) and you may be seeing this. The WS-2080 is a good station and I would bet the temp sensor is fine, that it is measuring it's surroundings correctly.

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #4 on: July 24, 2012, 06:34:12 AM »
so it is now 1.2 m above ground , and i have room to move to 3m above , is that acceptable?

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #5 on: July 24, 2012, 06:40:39 AM »
If the temperature sensor in the SRS100LX is 1.2m above ground (open grassy area) then that's ideal. But if it's over concrete that could be your issue and should be as far above it as possible.

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #6 on: July 24, 2012, 06:43:47 AM »
thanks DanS , i will move it up and see how it perform next 5 days where a heat wave is coming and keep updated

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #7 on: July 24, 2012, 06:49:01 AM »
Hope it helps. I have two stations mounted here, one installed per NWS/CWOP suggested guidelines (open grassy area) and the other mounted on the north side of the shaded (concrete) house. I see this effect on the house mounted station and that's what I am imaging you may be seeing as well.

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #8 on: July 24, 2012, 03:18:39 PM »
For calibration of ws-2080 are there standard values for temperature and other parameters, or how I can decide that it needs calibration or not

Raed

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #9 on: July 25, 2012, 07:09:17 AM »
the thing that confusing me , last night i setup the WS-5300 which I was having from last year but in not on same level of rooftop , on top of container where i growing plant, the Low was in WS-5300 : 22.6 , and in WS-2080 with SRS100LX : 23.9

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #10 on: July 25, 2012, 07:21:58 AM »
the thing that confusing me , last night i setup the WS-5300 which I was having from last year but in not on same level of rooftop , on top of container where i growing plant, the Low was in WS-5300 : 22.6 , and in WS-2080 with SRS100LX : 23.9

Different locations give different readings.  Your WS-5300 not "seeing" the warmth of the concrete that the WS-2080 saw possibly.

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #11 on: July 25, 2012, 07:38:55 AM »
i thinking now to move the ws-2080 to same location as I did in ws-5300, but i need to extend the cable , so if i use the RJ11 extension cable would it work as far as you know?

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #12 on: July 25, 2012, 08:45:57 AM »
Should work o.k as long as you watch for correct polarity, that is, there isn't a reversal in the extension. Yellow goes straight through to yellow position, red to red, etc. Reversing telephone (rj-11) adapters and cables exist.
« Last Edit: July 25, 2012, 07:57:16 PM by DanS »

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #13 on: July 31, 2012, 04:20:13 AM »
thanks DanS,after moved it down to the roof garden 145 cm above ground, readings now are more reliable


Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #14 on: July 31, 2012, 04:43:21 AM »
I;m trying also to correctly calibrating the temperature , I did as described in ambient manual using red spirit thermometer it shows
0.4-.06 less than the ws-2080 , are there are method to correcly calibrating it

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #15 on: July 31, 2012, 04:52:32 AM »
Other than software tweaks I don't believe there are 'adjustments' for the sensors. Also, how confident are you with the red spirit thermometer? Could it be reading 0.4-.06 too low?
« Last Edit: July 31, 2012, 05:06:20 AM by DanS »

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #16 on: July 31, 2012, 05:50:16 AM »
I got two red spirit thermometers different brand put all togather in room both show -0.4 to -0.6 less than ws-2080 , and this the only method i know to verify station temperature reading, also i may consider more thermometers as i read in a site by placing 10 red spirit thermometers with the station in room temperature and take readings after 48 hours then take the average less or more

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #17 on: July 31, 2012, 05:59:13 AM »
I know WUHU Software has tweaks to adjust these things but am unsure if the program is compatible with the Ws2080. Cumulus Software is another program online but I've never tried this one and unsure of the compatibility as well.

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #18 on: August 01, 2012, 07:40:29 AM »
I think I had another issue, last night the wind was completely calm, the reading was 2 degrees higher than expected , do calm conditions affect shield ventalition that lead to temperature reading errors

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #19 on: August 02, 2012, 07:28:53 AM »
Just an idea, if I put a solar powered mini fan beside to the shield will it do the job instead of having FARS

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #20 on: August 02, 2012, 07:52:57 AM »
The fact that you say this slightly higher reading was at night leads me to believe this temp reading may be caused by something either below or nearby the sensor radiating this difference. In the daytime with the sun shining directly on the shield I would expect the added warmth of the shield bowls to be included in the measurements, but at night, even with no breeze .... Nearby pavement, cement, bricks, stones, decking, etc. that were warmed from the daytime sun sounds more like it.
With regard to the solar fan you mention, if it's possible to mount it directly above the sensor (preferred) drawing up or below the sensor blowing up as well, you'd be better off then outside the shield blowing inside. Plus you mentioned the slightly higher readings were at night so the solar fan wouldn't help you there unless you rig it with rechargeable batteries for nighttime operation.
« Last Edit: August 02, 2012, 07:55:08 AM by DanS »

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #21 on: August 02, 2012, 10:24:24 AM »
Thanks DanS , also do you think if I put the shield inside a steveston screen is a good practice

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #22 on: August 08, 2012, 06:27:53 PM »
I think the srslx100 really has a problem ,now a calm midnight temperature recording 27.5 degree which too high for this so removed the sensor out of shield within 20 minutes temperature dropped.to 25which is more reasonable , could any one explain what really happening

Offline DanS

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Re: WS-2080 temperature accuracy
« Reply #23 on: August 08, 2012, 07:38:33 PM »
The first thing that comes to my mind is the temp/hygro sensor position in the shield. If it's mounted up at the top it could be reading a pocket of warmer air held inside of the top bowel. If this is where it is mounted try locating down as low as you can get it so that the rim of the top plate is high away from the sensor and it's out of this trapped air region.
« Last Edit: August 08, 2012, 07:43:17 PM by DanS »

Offline raedh

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Re: WS-2080 temperature accuracy
« Reply #24 on: August 09, 2012, 05:29:06 AM »
If I added spacer between plates , do you think would solve the issue?

 

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