Instructions for a galvanized steel pole mount
I'm quite surprised that AcuRite doesn't provide “detailed” instructions for this type of mount since it is a common mount for many people.
At any rate, buy a 3/4" galvanized steel pipe at your preferred length (typically sold in 6 ft. and 10 ft. lengths at any hardware store) and also a 3/4" galvanized “floor flange” to secure the pipe to whatever base location you choose. FYI, 3/4" indicates the thread size, the overall diameter of the pipe will be about 1 inch which will perfectly fit the required diameter for a snug fit of the 5 in 1 sensor.
Depending how you plan to mount, you may also need to purchase a 3/4" galvanized nipple (sold in various short lengths), and a 3/4" galvanized tee or 3/4" galvanized elbow. These are all inexpensive items. The entire cost for installation might be $30.00 if you needed to buy everything. If you look up these items on your favorite hardware store website, you'll easily be able to determine which installation design you want to go with and the total cost.
Using a compass (many free iPhone and Android apps available for download if you don't have one), identify due South at your mounting location. Draw a line or make a mark indicating North and South on your mounting surface. Attach the floor flange to your base mounting surface using the appropriate screws for whatever your're drilling in to (wood, metal, etc.). Once the floor flange is securely in place, do a test mount of all your mounting pieces (excluding the 5 in 1 sensor) and line everything up to your marks indicating North and South. Make a mark on the galvanized steel pipe itself lining it up with true South to indicate where it will settle in the flange when its tight on your final mount. Use this mark to know where to drill the holes on the pipe to insure that the 5 in 1 sensor on the threaded pipe will line up to true South.
When you place the 5 in 1 sensor on the pole it will appear tight, however I
highly recommend that you drill 2 small holes in the galvanized pipe to lock it in position (otherwise, it will move out of the required southern exposure with a strong gust
of wind). Drilling the holes in the pipe is consistent with the installation
instructions provided by AcuRite as if you were going to use the plastic
mounting bracket and screws provided with the sensor. Please note, the screws included with the
sensor are designed to penetrate the plastic on both the sensor and the
mounting bracket to lock it in place but they will not penetrate the galvanized
pipe, hence the need to drill out the holes
Place the 5 in 1 sensor on the pipe and push it as far down as it will go, then line it up to your mark indicating true South and mark the drilling holes. The proper sized holes can be very easily drilled using a 1/8" cobalt drill bit (I didn’t even need a bench vice to hold the pipe while drilling). You will then need to “tap” the holes to create threads in the galvanized pipe to lock the sensor in place. This is easily done by purchasing a pipe tap (often the cobalt drill bit and pipe tap are sold together for less than $10.00). You could buy self tapping machine screws, but I didn't go that way as I was worried they would wiggle on the pipe when I was drilling. Lastly, attach the sensor to the pipe using 2 number 8 screws @ 3⁄4” in length.
Important: Most likely the 5 in 1 sensor will be out of reach once you mount it to the top of the steel pipe. To insure the recommended southern exposure for the solar cells, do a test mount of just the pole (and your other mounting pieces) to the floor flange “before” permanently mounting the 5 in 1 sensor. Make a mark on both the flange and the pipe to indicate due south. Then, mount the 5 in 1 sensor to the pipe and screw it into the floor flange. Minor adjustments can be made at that time to dial in true south, but the installation should still be solid.
My personal thanks go to Tim Gilroy and Ledrak for having the Community discussion that lead me to this easy installation.