I mounted mine "temporarily" to the backstay and it has stayed there for the last three seasons. Works for me.
That's a Kaindl. Tough little brutes. I had one on a pole in Wyoming for over two years, about one year for each battery. Ran 24/7, and logged for up to a week without reset before going to sleep. By 'logging' I mean saving max and average wind speeds. Nice unit.
I assume you are referring to some hand held meter. Just keep in mind they are useful for wind speed only at your eye level which is essentially unrelated to that which the sails "see".
Actually there is a relationship between the two. When my wife and I are down at the marina we often walk out onto the breakwater to see how rough and windy it is before preparing to get under way. I try to remember the windmeter when we look. Standing on the breakwater we are at about the height of the spreader on a smaller sailboat, say midsail. She will look and tell me it is 20-25 knots out there, look at all the white caps, so we better stay at the dock. So I pull out the little SkyMate and show her it is only 12-15 knots, let's get under way I say. With a bit of coaxing I can usually get her out there. Sometimes we are on a trip and we are at some other marina when it starts blowing and if it shows 15+ at the dock I know it is a bit stronger up on the sail and decide to stay put rather than put the fear of God into her. Those little instruments are handy to have but I always use mine around the shores first.
I like that Kaindl model that Heinzir has on the back stay!