Proper station setup can be a trying process. Hopefully, this information will help those looking to setup their own weather station.
Mounting the anemometer can be a challenge for new weather station owners. According to CWOP Weather Station Guide, ideally an anemometer should be mounted 33 feet off the ground in an open area. So, if you don't own a ladder, now is a good time to borrow one.
Before we discuss how I mounted mine, we want to talk options. The anemometer can be mounted on tripod on the ground (using Guy Wires) or on a structure using a pole and straps. The pole can be aluminum, steel, or PVC piping.
Since I have children, mounting the anemometer on the ground is a recipe for disaster. Since our new VP2 is wireless, I decided to mount it on our kids huge playset in the backyard. I also decided that I don't like mounting long, pointy metal things into the air (they're called lightning rods). So, I opted to make my pole out of PVC.
Our local home improvement megastore has 5 foot PVC pipes. I took a 3/4 inch pipe and siliconed it inside of a 1 1/4 inch pipe to provide extra rigidity. I then capped it and mounted to the roof support beam on the playset with some 1 1/4 inch metal straps. Don't forget to check for level and correct orientation with a compass.
I know Davis shows the anemometer mounted to the ISS, but putting an anemometer down low is not a good way to measure wind and putting the ISS up high is not a good way to measure temperature/humidity. This is why Davis provides a long cable so you can separate the anemometer and put it up high.
Below discusses our old anemometer...
So like many, I chose to mount it on my house.
Mounting to the house can present some challenges of it's own. Not only is the roof higher then most people are comfortable with, but there's the challenge of attaching the anemometer somehow to something and get it up there.
I strongly recommend you don't start putting holes in your roof.
As soon as I receiving my station in the mail, I went out and bought a hodgepodge of items to get my anemometer mounted. What I did was purchase a cast iron flange, a three-foot black cast iron pipe, a cast iron 90-degree elbow, and an aluminum extendable painter's pole, and some metal straps.
I secured the heavy flange to a support strut on the house, screwed the pipe into the flange, the elbow into the pipe. This made a very solid mounting base for the pole, and got the mount out from under the lip of the roof.
I then screwed the pole into the cast iron elbow, leveled the pole, and strapped the pole to the side of the roof with a wood spacer for increased stability. After climbing up on the roof and attaching the anemometer to the extension, I lifted the extension into the air. I checked for alignment with a compass and bolted the extension and the pole together for stability.
Of course, the advantage of using an extendable pole is that I can raise and lower the anemometer easily. The disadvantage is that it's a little wobbly in heavy winds.
More on Anemometer
According to the CWOP Weather Station Guide, ideally thermometer and hygrometer sensors should be mounted 5 feet off the ground in an open area, at least 100 feet from areas of concrete or asphalt. The sensor should have a radiation shield to protect from the heat of the sun and good ventilation. Of course, living in an urban environment won't allow for optimal placement.
Since the Davis integrated sensor suite (ISS) is wireless and has the radiation shield built in, I mounted the ISS on the swing (on the playset in the backyard), about 6 feet off the ground, being sure to level it for the rain gauge.
I opted for - and strongly recommend - the 24-hour fan aspirated version of the VP2. This prevents buildup of an air pocket in the radiation shield during calm days. It also pulls air over the sensor on hot summer days, allowing for a much more accurate reading.
Below discusses our old thermo-hygro sensor...
Since I have kids and the sensor has to be in the front yard, I opted to put mine under the eave of our split-level house. The housing that comes with the thermo-hygro unit is inadequate for an outdoor environment, I removed it and opted to use an inexpensive ordinary plastic utility basket as the protective housing. This keeps both the elements and inquistive children away from the unit.
Sterilite makes just the basket I was looking for - it's white, has precut ventilation holes, and is rugged enough to hold up outdoors. I then mounted the sensor unit up under the eave on the north east side of the house, and the basket... er... protective housing over the unit.
However, in the fall of 2004, I soon noticed a problem with my setup. During the morning hours with little or no wind, my temperature was not getting as cold as other area sensors. This is due to a pocket of warm night air being trapped under the eaves.
The solution? I got out my trusty dremel and cut a hole in the protective housing large enough for a small 120mm 12v computer fan. I added a debris screen in front of the fan to protect it. This setup allows the sensor to be continually bathed in air and also keeps pesky insects out of the sensor housing.
With fan in place, the sensor has been very accurate, perhaps even more than a sensor out in the open. During even the warmest of days, my sensor sits in the shade.
Self-built Radiation Shields
More on Davis Instruments Doc on Importance of a Fan (PDF)
More on Stevenson Screen
More on Thermometer
More on Hygrometer
The self-tipping rain gauge is pretty self-explanatory for mounting. You want to make sure it's in an unobstructed spot, with good drainage, securely mounted, and as level as possible. I suggest a spot that's easily accessible because you'll want to clean it once a year or so.
Ours is mounted on top of the ISS, about 6 feet off the ground
Below discusses our old rain gauge...
I mounted mine with an "L" bracket to my anemometer pole about 10 feet off the ground, away from and above the roof of the house. It's a little higher than some recommend but few setups are perfect. Using a manual gauge and the nearby METAR to check for accuracy, I'm comfortable with it's performance.
More on Rain Gauge
- CWOP Station Setup Guide (PDF)
- WMO - Guidance on Urban Setup (PDF)
- AmbientWeather Setup Guide
- Campbell Scientific Weather Station Siting (PDF)
- WeatherShack Weather Station Set Up (PDF)
Other Weather Station Setups
- CWOP station pictures on Flickr
- Davis wireless on backyard metal tower
- 1-Wire metal pole on house
- Davis wireless on playhouse with metal pole
- Davis wireless on post with metal pole
- WS-2310 on shed with metal pole
- Davis on metal pole on roof
- WMR928N on metal pole on back fence
- WS-2310 on metal and PVC, roof and backyard
- Davis wireless on metal pole on roof
- No pictures but nice blog on setting up a station