Tin roof.

Hi all, just joined and totally new to this stuff. More used to fishing and surfing, but that relates to weather, so it all fits together. Just bought a Fine Offset WH 3081, and had planned to mount it atop the ridge of my galvanized iron roof [13 degree pitch] for easy accessibility, but started worrying about solar reflection affecting temperature and humidity readings. This location is almost the only place to get accurate wind readings at the house, and would only be around 10m from the base station. The supplied post is obviously to short, and was wondering if anyone had worked out a minimum distance where reflected radiation was no longer a problem. Built the house myself, so I know about the reflected heat. With a step ladder, I can probably go to about 3m above the ridge. Have another option, a crows nest in a dead tree, almost line of sight to the base station, but 40m away. This spot is quite exposed and above the nearest hill, but I will need to drop a couple of trees to expose the anemometer and rain sensor to clear air. Also, it is about 16m up, and I’m not real keen on climbing that too often to do adjustments or repairs. Am easily able to build all sorts of reflectors or shelters to stabilise the instruments.

Given your options, I’d suggest putting the anemometer on the roof and getting an extra temperature sensor to locate in a more temperature-friendly location.

If you go with the rooftop location, you will need to ensure that the temperature sensor is as well screened from both direct and reflected radiation as possible. A single-louvered (pie-plate style) radiation shield will not do it, because it will let in radiation from below. You would need a double-louvered radiation shield, along the lines of a Stevenson screen, that shields against radiation from all directions.