I am beginning to think that a Davis VP2 may be beyond my budget (when considering the UK price) and am leaning more towards the Oregon 928 (968 in USA I think) instead.
Can any users give me some feedback regarding there experience with this equipment?
How reliable is it?
Are you happy with the data?
How far away have you been able to mount the sensors?
All comments gratefully received!
I’ve been using a WMR928N for the last 2 years. So far it’s been pretty reliable. The only failure I’ve had was a remote thermo/hygro sensor which I’d been using as a solar sensor in a jar. I suspect that under the extremes of heat/cold and humidity that damp got into it. It still shows the temperature but the humidity is stuck at 10%
The data seems reasonable. You can’t get to 100% humidity (but 98% is close enough). Gust speeds aren’t as high as the local airport, but that’s probably more down to location than the anemometer. The rain gauge could do with having a bit more resolution (it’s only 1mm increments) but I could fix that by adding a larger collector onto it if I wanted to.
Updates aren’t as fast as a wired unit or a VP, but they’re not too bad.
Approx distances from my console…
External temp/hum sensor - 20ft
Anemometer - 30ft
Rain gauge - 40ft
Solar jar - 30ft
Greenhouse temp/humid - 60ft
I’m not aware of losing any data under normal conditions, but when the batteries in the more distant temp/hum sensors get low they drop out, but that’s to be expected.
All in all I’m happy with my WMR928. If I had more money I might be tempted by the VP, but the OS equipment is a reasonable compromise.
I go along with what Chris has already said - I have had my WMR928N for just over 12 months now - nothing has failed yet (fingers crossed) - the only batteries replaced so far are for the indoor temp/hum/pressure sensor.
Some crucial wind gusts could be missed as the polling interval is not frequent, but that is down to wireless radio transmission regulations - the unit remembers the highest gust anyway in between data transmissions and sends that to the console (well it is supposed to!)
I also wish the default rain tip was not as much as 1mm - light showers will often be missed.
Make sure the outdoor temp/hum sensor is well sheltered from the sun or the readings will be too high in summer etc.
The cost of Davis stations is ridiculous in the UK compared to the USA especially when you want Solar/UV/Wireless/FARS options - the cost of the basic cabled unit isn’t so bad - but still a lot of money.
I really do hope to upgrade to a Davis one day - but the OS is fine for my needs at the moment as a weather hobby.
I’ve had my WMR-968 since late last Summer (2004) and for the most part have experienced trouble free operation.
I am also quite happy with my wmr928n.
Annoying part is that I never see it above 98% humidity. (adjusted to 100% in WD but WDL still show 98%)
And how do you make a solar sensor??
It annoys me to no end that I can’t buy solar and UV additions to the “real” weatherstation, but you get them for the small table ones…
And … how do you make a solar sensor from a thermo/hygro meter in a jar ???
It is also a little annoying that oregon don’t have radiation shields available for the station, whereas this is built into a davis vantage pro.
So had I known it stops at 98% humidity, no realistic option for a solar and UV meter and you HAVE to make/buy a radiation shield, I would have gotten a Davis … But as I said, I AM quite happy with my station, it is reliable etc. just slightly “incomplete”
R*
Hi,
I’m an absolute newbee on this subject … I’ve an WMR928N and would like to have a larger rain collector (I keep missing those light showers). Can someone give some pointers where to buy something like that, or how to build it oneselves?
TIA, cu,
Chow.
I don’t know whether there are such shops in Holland, but home brewing shops in the UK sell large funnels…up to 12 inches (30cm) and maybe bigger. Shops selling kitchen utensils may have funnels, but I suspect they’re usually smaller.
You then put the funnel on top of your rain gauge and adjust the tip rate in WD to match the size of the funnel (using circular area calculations). I think the WMR928 has a 10cm diameter gathering area, so the area of this = PI * (10/2) ^ 2. Ignoring PI (because you’ll be dividing by it later) this gives an area of 25 (not cm2 because we’ve ignore PI). The surface area of a 30cm diameter funnel = PI * (30/2) ^ 2. Again ignoring PI this gives an area of 225. Divide the new area by the old (225/25) gives the increase in area…in this case exactly 9 times the area. So you’d use 1/9 (0.11111) as the new tip rate in WD.
Brian…if you read this…how many decimal places does the adjustment for large rain gathering areas have? With a 12inch funnel I’d need 4 to be reasonably accurate over a year. Does it go to this level of accuracy?
yup, you can use that 0.1111 wd, will use that and not round it or the result
I’ve been meaning to increase the size of my collector, so maybe I’ll do it this year! The local homebrew shop has a 20cm funnel on their web site, so that would give me a useful increase to .25mm/tip. I still fancy finding a 12inch funnel though to get down almost to 0.1mm resolution.
one problem that you might run into is that you migth overload the wmr968, and it will just come up with a overload message for the rain rate…but dont quote me on that…but i sort of seem to remember some discussion about that issue on the weather matrix forum…or was that with the wm918
the other thing is the wmr968 only gets a new reading every 15 seconds for rain…and so i wonder if the actual rain sensor is only checking for which way the tipping bucket has tipped every 15 seconds too…i.e it might miss tips in between with a large funnel colleciton lots of rain…but i am just guessing …so just things to consider 
I too have a WMR928N and am satisfied so far.
As one of the posts said, in very cold and snowy weather my anemometer has frozen and I shall follow his advice. To enable ease of siting the thermo/hygometer in shade, I bought a 10 metre extension cable. Similarly with the first mounting of the anemometer for ease of resetting tne transmitter or in the event of battery replacement.
All transmitters are together and about 120’ from the console. I have tried the console at a nearby house and it received perfectly at double this distance and not in direct line of sight. (I think the Davis has to be line of sight)
I have been tempted to increase the diameter of the rain gauge to give a tilt to detect light rain or a shower, but that is not a priority.
For the price in the UK I think that it’s excellent value for money.
John
The WMR928 specs suggest that it can cope with a maximum rain rate of 999mm/hour, so that’s a tip every 16 seconds. However, I have managed to record a maximum rain rate of 10mm/min or 10 tips in a minute with the standard collector. This suggests that the gauge remembers how many tips since the last transmission and sends that number in the next transmission.
Increasing the accuracy to 0.1mm might prove tricky in the 10mm/min downpour. With the current collector that was a tip every 6 seconds. At 0.1mm/tip that’s a tip every 0.6 seconds which might be pushing it a little.
I’ve still got my old (admittedly wired) WM918, so I an do some tests on that rain gauge to see how it copes with high rain rates!
I have a question about using a larger funnel…I also have a WMR968 and I would like my rain readings to be 0.01" instead of 0.04". Now do I just put a 12" funnel on top of the rain collector and secure it? Also, in order for it to read the 0.01", I don’t have to have WD, so it will show up on my console, right? Thanks for all of your help!
the console will over read the rainfall by the factor of the increased rain collection, and so the console rain totals wil no longer be accurate
So are you basically saying not to use this?
I have heard, though, that some people used a larger funnel to make the rainfall totals show up as 0.01" instead of 0.04"…is there a certain way to do this?
Thanks for all of the help.
yes, by all means do it
and you can just then set a new rain adjust factor in WD
what i am saying is that the console’s rain totals will no longer be correct, but the software’s total’s will still be, if you set the correction factor correct
i think you are getting a bit confused
I don’t think he uses the software, so
a) Yes, if he adds a funnel it will take less rain to tip the rain gauge.
BUT
b) The console will still register the standard amount per tip
SO
c) If the area of the funnel is (for example) 4 times the area of the standard gauge, the rain total displayed on the console will be 4 times the actual amount of rain.
Niko, you are right…I do not use WD, so I guess I’m not going to use this funnel. Thanks for the help though guys!
So does that basically mean that no matter what I try, I will never be able to use a larger funnel on my rain guage unless I have WD, or another weather station software program running? Thanks for the help.