Cumulus Support

There is currently only one Cumulus site in South Africa. We are in the process of setting one up at our school, Felixton College on the east coast at 28°49'41.84"S 31°53'37.23"E. Being a school, cost is a critical factor. We are considering a Davis Vue or a National Geographic 265NC. We can get the 265NC at half the price of the Davis, but it is not listed on the Cumulus site as supported hardware. However, it is listed as the weather station in use at a Cumulus site in Canada (Dave's Weather Station on Darlington Cr., Windsor Ont.).

I am a Java and C++ programmer as well as a part time electronics engineer, so I don't mind tinkering a little but would much prefer a ready-made solution because of time constraints. Can anyone advise me on compatibility?

Thank you
Ken Krige

Hi Ken

The Wiki shows the 265NC as a supported device

http://wiki.sandaysoft.com/a/Supported_Devices

The 265NC is the Fine Offset (rebranded). I have one and it works fine with Cumulus. I'm also quite pleased with the acuracy. I'm not sure about long term reliability - I've only had it a couple months.

Ken, I am biased...

I highly recommend that you pay the additional costs and get the Davis Vantage Vue - it might be a new weather station but it has been built on the experience and knowledge acquired by Davis from its Vantage Pro weather stations.

As expressed many times, one gets what one's pay for, and when one buys a Davis Instruments weather station, one buys reliability and good performances - a Davis weather station has an expected life expectancy of 10+ years.

I am not familiar with the National Geographic 265NC - available here in Canada for $99 CA whereas the Davis Vantage Vue plus the WeatherLink adaptor is costing $525 CA...

From what I have read about the the National Geographic weather station, it is similar to the FineOffset type of weather stations where accurate weather information and reliability can be an issue...

As I indicated at the beginning of my message, I am somewhat (very) biased - I have had a Vantage Pro 2 Plus weather station for almost 3 years and a Vantage Vue (console-only) for about 6 months; the only upkeep I had to do to the ISS (the integrated sensor suite - the external unit where all the sensors are located) was to remove some tree leaves and needles that had blocked the rain collector cone and to dust off the unit - no down time in almost 3 years - no battery replacement in almost 3 years (the Davis weather stations are equipped with a solar panel that recharges the battery powering the ISS on cloudy days and at nights) - 100% accuracy - 100% reliability.

I know that I am going to get some complaining (bitching ) from users of those low priced and more-or-less reliable weather stations...

Thanks for the info.

Accurate, reliable data is an issue for us. We regularly get temperatures in the mid to high thirties (Celcius), coupled with high humidity. As a result, sport often has to be cancelled in February, which is the worst part of our summer. We do not want to do this too often as it causes major disappointment to children and inconvenience to their parents. We also do not want them to play when it is a potential health hazard. We have a discomfort index based on temp and humidity and cutoff values from local physicians. In short, important decisions are being made on the information. We currently get readings from a weather station in the nearest city, but we know from experience that their weather differs sinificantly from ours on some days.

Is the Davis significantly more accurate than the 265NC for temperature and humidity specifically?

Thanks
Ken

kkrige wrote:Is the Davis significantly more accurate than the 265NC for temperature and humidity specifically?

The figures quoted by Davis for the Vue are:

Temperature accuracy: 1 F
Humidity range: 0 to 100%
Humidity accuracy: 3 to 4%

Fine Offset quote a humidity range of 10 to 99%, but they don't appear to give any accuracy figures. They quote resolution, but that's a different matter altogether, of course.

I have a Davis VP2 and a Fine Offset with the sensors sited quite close together. The temperature readings are usually fairly close - currently the FO is saying 1.6C and the Davis 1.8C. Humidity is a different matter; they often differ by quite a bit. Right now the Davis is showing 75% and the FO 73%, which isn't bad, but the FO seems to get much worse when the RH is higher.

Ken...

One of the advantage of the Davis Vantage Pro 2 Plus weather stations (the 'plus' meaning that the ISS is equiped with both a solar radiation and a UV sensor) over the Vantage Vue, is that it can produce (display), not only solar and UV readings, but it can also produce an 'evapotranspiration' reading - "...evapotranspiration (ET) is a measurement of the amount of water vapor returned to the air in a given area. It combines the amount of water vapor returned through evaporation (from wet surfaces) with the amount of water vapor returned through transpiration (exhaling of moisture through plant stomata) to arrive at a total. Effectively, ET is the opposite of rainfall, and it is expressed in the same units of measure (inches, millimeters). The Vantage Vue uses air temperature, relative humidity, barometric pressure, average wind speed, and solar radiation data to estimate ET, which is calculated once an hour on the hour. Measuring ET requires that the Vantage Vue console listen to a an optional Vantage Pro2 Plus station with a solar radiation sensor installed...".

On the Vantage Pro2 Plus console (as well as on the Vantage Vue console), an alarm can be set when the ET value exceeds a preset threshold ... which would be an automatic way of deciding if sport activities are to take place...

Just another option/suggestion...

If your application demands professional quality gear (and you budget can support it), you should not be considering either of these hobby class systems. If you believe you can make do with a hobby class system, you certainly won't see a 5X improvement in the Davis to justify the 5X cost increment.
I've had several low end systems, and I know there is some definite junk out there. My experience to date is that the 265NC should not be grouped at the junk end of the spectrum despite it's cost, but rather it fits closer to the mid range, just slightly below the Davis. My recommendation would be to use the 265NC and spend the difference in money on something else (like more sports equipment).
The Davis is a quality machine and offers some additional measurements as others have posted. Both offer the ability to set alarms - the Davis has a bit nicer display. If you are only interested in temperature and humidity, there are other lower cost alternatives as well.
This can be a bit of a "PC / Mac / Linux" religious debate as you may have noticed.

Thanks for all the advice. We bought a National Geographic. Check out our site at www.felixtoncollege.co.za/apps/Weather if you can stand the heat.

Good choice - it is warm (half boiling! ) based upon the heat index. I'm sure the children and you will enjoy the new toy .