Until recently I lived in Scotland where UV is hardly ever an issue given the hideous weather we tend to get there. However, I now live in New Jersey in the USA where the summers can be very hot and the risks of UV exposure are more of a concern for me. Given that I took my weather station with me when I relocated (which comprises of both the WMR88 and WMR200 base stations) it made sense to consider expanding its capability to record UV.
One of the advantages of Oregon Scientific’s range of wireless weather stations is the ability to add extra sensors. I have, for example, previously taken advantage of this by adding an additional temperature and humidity sensor in the form of a THGR810 unit.
Both of my base stations also support a UV sensor in the form of the UVN800. This sensor is not normally bundled with the WMR88 or WMR200 but I purchased one recently as an add-on. The unit normally retails for $59.99 but I was able to pick it up for $43.79 from Amazon (not including sales tax). Both the full and discounted prices are on par with what I would expect to pay for other additional sensors such as the THGR810 mentioned above. It arrived undamaged and well packaged in a relatively small box:
Upon unboxing I was presented with the UVN800 unit itself, a wall mount with two screws, a ground spike, AA batteries and instructions.
This provided me with two different installation options. Either use the ground spike to insert the sensor in the ground or the wall mount and screws to attach it to a wall or pole. I chose the wall mount option which I attached to my existing sensor pole. However, I appreciate the flexibility of the ground spike option. The trick with the UVN800 is to orient it such that the UV sensor on top of it has a constant, uninterrupted view of the sky which I could more easily achieve with the pole mounting.
Installation of the UVN800 is fairly straight forward if a little more awkward than it could be due to some weird choices made by the unit’s designers. First of all accessing the battery compartment requires the removal of four small screws from the base of the unit to access the battery compartment. Why the compartment is not accessed by a sliding mechanism like most of Oregon’s sensors is a mystery.
Secondly the wall mount is screwed into place at the bottom of the unit obscuring the battery compartment and reset button. Given my pole mounted configuration changing batteries will be far more time-consuming than it should be. I will have to unscrew the wall mount from the pole, detach the sensor from the wall mount, remove the screws from the battery compartment. Only then can I change the batteries and will then have to reverse the procedure to reinstall the unit.
So far this is my only gripe with the UVN800 and it is not a deal breaker by any means. One the batteries were installed pairing it with my base stations was as simple as hitting the sensor’s reset button and initiating a search from each base station. They both started displaying UV Index readings straight away. On both the WMR88 and WMR200 this takes the form of a live UV Index display and a graph of the last 10 hours of values.
Having UV Index values displayed on my base stations was just the start, however. I publish weather data to my own website and wanted to add UV Index information to it. I use a Meteo Sheeva connected to my WMR200 as a data logger and to do uploads of weather readings and graphs to my website. As expected it was a snap to get it to start logging data from the UVN800. As an example here is one of several graphs I have configured on the Meteo Sheeva which display the last 7 days of maximum UV Index values:
My Meteo Sheeva also uploads data in WD Live’s clientraw.txt format which includes UV Index readings. I have rearranged my existing WD Live console on my website to incorporate a UV Index bar:
Finally I wanted to be able to see up-to-date UV readings when I am outside. To do this I ideally want to be able to see the current UV Index on my phone. One of my winter projects was to develop an Android widget which displays the values found in online WD Live clientraw.txt files. The data the widget displays is user configurable and one of the options is for colour coded UV Index values:
The widget is pretty much production ready and supports 18 different weather data points and 16 different measurement units. I use the widget extensively for both my own weather station and others close by locally or when I travel. However, at this time I am not sure whether or not I will publish it on the Google Play Store given how many similar apps are already available.
Returning to the UVN800 itself there is one more thing to note. The reviews on Amazon for the UVN800 indicate that many units permanently fail just after a year of operation. At the time of writing I have only been operating the sensor for a few days but will add a note to this review if and when it fails.
Should the sensor last at least a couple of years (as all my other sensors have already done) then I would not hesitate to recommend the UVN800 as a useful, easy to use addition to an existing Oregon Scientific wireless station.