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Solar sensor for WMR88?

Posted: Wed 20 Aug 2014 12:07 pm
by Tony_J
I have a UV sensor working with my WMR88, but as others have observed, I just get a UV index value in the Cumulus display and no Solar Rad, because it is just a UV sensor and not a solar sensor.

Is it possible to add a solar sensor to the WMR88?

Re: Solar sensor for WMR88?

Posted: Thu 21 Aug 2014 10:24 am
by steve
OS don't seem to do a solar sensor for their stations, and there is nothing in the (unofficial) protocol description that would allow Cumulus to read one.

Re: Solar sensor for WMR88?

Posted: Fri 22 Aug 2014 8:49 am
by Tony_J
steve wrote:OS don't seem to do a solar sensor for their stations, and there is nothing in the (unofficial) protocol description that would allow Cumulus to read one.
OK thanks Steve

Re: Solar sensor for WMR88?

Posted: Fri 22 Aug 2014 8:51 am
by Tony_J
Any views on inexpensive systems that do include solar sensors? I know that Davis are the dog's whatsits, but the price is a tad eye-watering :(

Re: Solar sensor for WMR88?

Posted: Fri 22 Aug 2014 5:00 pm
by AllyCat
Hi Tony,

Well, there is the Fine Offset WH-308x series, but I really can't "recommend" them. Here are my personal views and observations:

Firstly, on the positive side, we do like the neatness and clarity of the Console/LCD, compared with the "touchscreen" versions (WH-1080, etc.) and the "Solar Pod" (circuit board) appears to be manufactured to a far higher standard than the other FO modules. If the complete station were only slightly more expensive than the 108x version then I would probably have bought another (for my "second location"), but they seem to cost almost twice as much as the touchscreen versions (when "on offer"). So now for the cons :

The "early" versions (WH-3080/1) had serious design and manufacturing flaws. Some probably now have been overcome (in the WH-3083 ? ) but we've not seen much evidence on this forum.

The (supplied) "Rechargeable Alkaline" Cells are basically a "rubbish" technology and there is no clear replacement type when they fail (perhaps quite soon). Since the memory chip is the same size (as the 108x), the logger stores less records (c3000 compared with c4000).

The "normal" light level is reported in Lux (not watts / square metre) and strictly, conversion is not possible. Actually, it appears that the sensor chip might be more suited to w/m2 measurement than Lux, but the later versions which offer a w/m2 option (WH-3083?) seem to have a major calibration/conversion error (by a factor of about 5).

The official "UV Index" is a very "difficult" measurement (probably why the Davis sensor alone costs around £500) and I don't believe that the FO measurement is remotely "accurate". But I must declare that IMHO "UV" is a pointless measurement anyway (if done cheaply). It has little relevance to weather forecasting and if you're worried about skin damage then slap on some factor 40 suncream !

But the major issue with the Solar Pod is that it's permanently attached to the "Sun Shield" (via a short, captive cable). It's almost impossible to find a location where the Pod will "see" the sun, but the external temperature measurement not be seriously elevated by direct sunlight. However, now that I have extended my cable and mounted the Pod up with the Wind sensors, I'm quite "happy" with the results, but it was far from a trivial modification.

Cheers, Alan.

Re: Solar sensor for WMR88?

Posted: Sat 23 Aug 2014 10:02 am
by Tony_J
Hi Alan

Thanks - that is most helpful. I guess I may just have to save up my pennies for a Davis in due course... :(

Regards,
Tony

Re: Solar sensor for WMR88?

Posted: Sat 23 Aug 2014 12:37 pm
by SpaceWalker
Tony, while saving your 'pennies', remember that the only type of Davis Instruments weather station that can process the data from either or both a UV sensor and a solar radiation sensor is the Vantage Pro2 - the Vantage Vue cannot process the data from either sensors.

The sensors can be purchased individually (at obvious higher costs) - the better deal is the Vantage Pro2 Plus weather station which comes with the two sensors as well as a the required mounting plate.

Also remember that you will also have to purchase on of the different WeatherLink data logger available - the unit acts a an interface between the weather station console and the computer.

The Davis Instruments weather station are, indeed, very expensive. But they are also among the most reliable weather station - some Vantage Pro (the old discontinued model) have been in continuous operation for more than 15 years (my Vantage Pro2 Plus station has been in operation for 10 years with no problem whatsoever and only one ISS battery change).

Re: Solar sensor for WMR88?

Posted: Sat 23 Aug 2014 6:49 pm
by Tony_J
Thanks Rob...I will bear that in mind!