Some times no often there is a strange problem at some anemometer ws-2300 model ,sometime at day or better some hours at day,the anemometer it can to show wrong direction wind ,exable we have south wind and it stuck and show continuity North or west wind for some hours.After some hours it work well again.For this problem the anemometer it had inside over to PCB 4 photodiode ,and all around in side base it have black paint for the sun not come inside , at some marks the paint it go away,and for this reasons,the sun goes inside to photodiode some hours at day ,and for this reasons the anemometer it had wrong direction wind readings some hours at day .Carefully i open the anemometer and i put around to base new black paint for plastic and the problem fix it .