Anemometer problem

[Gaetan Cormier]

Hello!

I was wondering if any of you had problems with the Oregon Scientifics Anemometer of the WMR968 wireless station.

It was intalled just recently here in Montreal during extreme cold conditions (-28C / -40 with windchill factor), so I'm wondering if cold is the problem? Any of you had similar experiences?

 

[Tim Stoecklein]

Mine has not worked for about a year now. There are a number of instances such as ours out there. If you do a search online you will come up with others' stories and remedies. Good luck!

Tim

 

[Gaetan Cormier]

Well, problem solved!!!!

After dismantling the anemometer I found out that some humidity was inside, so probably froze the thing.. it's working now properly and for a long time ( I hope :roll: )

 

[Stuart Robinson]

The anemmoeter on my old WMR298 always under read by about 25% - it was finally distroyed by debris under Hurricane Ivan so now i use Davis Equipment.

This has not added much to the discussion has it sorry.

 

[John Diel]

Does the OSI Anemometer have drip rings? I know the Davis units do. They send them out along with the replacement cups. That seems to help some in keeping the water down to a mangeable level.

It's 9 F here and my Anemometer appears to be working pretty well. Of, course I haven't hit any birds recently, nor have we had any precip to test it out.

John

 

[Robert Dewey]

The anemmoeter on my old WMR298 always under read by about 25% - it was finally distroyed by debris under Hurricane Ivan so now i use Davis Equipment.

This has not added much to the discussion has it sorry.

I have an anemometer that's about the same. Sometimes it reads well below what the actual wind speed is, and sometimes it reads the wind speed absurdly high. One example, was we had a severe thunderstorm roll through, which knocked a couple trees down in my backyard... The anemometer only read 50MPH... Then, during a synoptic scale windstorm, we had a gust to 55-65MPH, it read 92MPH!

 

[John Diel]

Since mine resides on my vehicle (just to lazy to pull it off) I can gage it by my speedometer. If I know the general wind speed and direction, I can generally get a good reading by driving into the wind. Not always possible, but it certainly gives me a general number to gage by.

So far, the Davis has been very accurate. I've compared with other Spotters using Davis, OSI, Kestrel, and a couple of others I can't remember the names of.

Davis Instruments updates faster than OSI. Kestrel is pretty much real time, but highly dependent on how it's held. I also found that Davis is the most accurate with no fluctuations on a calm day. I did the testing with some local chasers and a couple of Skywarn folks.

The only thing we found to be more accurate was the RM Young instruments. Of course those are way out of our budget. I'm using a Davis Weather Monitor II and the other one tested was the Davis Weather Wizard III. There were also a couple of Pro Vantages set to a custom Mag Mount configuration.

We did notice differences in moving tests. My mount is on a telescopic mast and raised about 4 feet above the vehicle. Those that were fixed mounts would show speeds a bit higher (appox 1 to 2 feet above the vehicle roof). Those that were mounted closer to the roof generally showed much higher wind speeds. Hands held (Kestrel and anotehr one) were way off.

John

 

[B Ozanne]

It just hit me that a bomb-proof anemometer for your roof would be a pitot version. There are almost no moving parts and you could make it yourself. A pitot anemometer is just an exposed tube that points into the wind. The tube is connected to a reservoir of colored liquid and the air pressure pushes up the liquid when the wind blows. It might be hard to read when you are driving, but good when you are stopped. I have seen some cheap, pre-made ones on the internet. If you made your own you could calibrate it by driving, as long as there is no wind.

 

[carey libby]

i have a ww3 by Davis and have only one problem with it.even though the wind vane moves,the direction it points and the dial on the WW don't match up.the wind vane can point south,but the digital arrow on the WW points like NE.
other than that,the wind speed is pretty accurate.i use it on my car,but only put it up on the day of the chase(found that if you leave it up all the time,the sind cups break off after a week or two because of the constant abuse).

 

[John Diel]

Carey,

Is the wind direction off by the same increment all the time? You probably just need to pull the vane off, turn the post until it point north on the display and put the vane back on taking care that it's also pointing north when you do this.

I haven't had any trouble with the cups breaking off due to normal driving conditions. I have lost a couple due to bird hots though. I always have a couple of spares with me for this reason.

I also found that if you put in another set screw where the instrument goes on the shaft, this will keep the vane and cups from twisting when large trucks go by. You can twist one of these right off the shaft if your not careful. The large cups tend to break faster than the small cups, but again, I've only lost a couple and those were bird hits.

John

 

[B Ozanne]

Any consumer grade 3-cup anemometer is not designed to be run on top of your car for long periods. They are designed for 5-10mph winds on top of your house, not 75mph winds for hours at a time. The bearings just can't handle it and the accuracy will drift. I recommend taking off the cups if you aren't gathering data while driving.

 

[carey libby]

john,
i have calibrated it so many times that i could rebuild a WW in no time :lol:
but when i contacted Davis,they told me to run down the cables and see if there were any nicks or cuts in the wires.there wasn't.after a small list of what to look for,they told me to just send it in for repairs.i haven't done this yet.i have talked to my Skywarn OP.about this and he told me that wind speed is much more important than direction.with that in mind,i don't worry about direction(besides,i don't need a wind vane to tell me what direction the wind is coming from,that is what my eyes are for :wink: )

B,
i agree with you(along with the other chasers)that the big cups don't hold out near as long as the small cups.after going through four large cups,i am now on the small cups.
the way i have my setup on my car where is i got a T-shape PVC pipe,turnt it upside down,got another piece of PVC pipe(cut about 3 foot)and glued them together with welders glue and left it overnight to dry(extremley hard bond).i then got some small hose clamps and with the PVC attached it to the luggage rack to my car.this makes it easy to slide the anometer up and down the PVC by just unscrewing the Ubolts a little and tighten it back up when i need it.