Do any professional aerial/dish installers use these?
There's usually two reasons for this question. Either it's "Is it worth buying?", or you've had someone turn up claiming to be a pro but using that kind of meter.
To answer the "is it worth it" question, it depends what you're trying to do. If the answer is to put up your own satellite dish for Sky then the meter will work okay for fine tuning the final position. It's no good though for telling you if you've found the correct satellite.
For DIY TV aerial installation then it's better than this
because the scale has greater range and finer graduations. As long as you know the bearing to the transmission mast then it will help get the final angle fairly close. The things it won't do is let you see if what the strength is of each mux and how much error there is in the signal. That's because the Fringe meter works on some kind of averaged or peak scale.
A proper Pro meter has a range of display screens. One of the most useful I find is the slope. This gives the readings of all the muxes and comparative signal levels.
What you're seeing above is the reading from an aerial with a very flat response. Flat is good. It means that the aerial is equally* good picking up muxes at the lower end of the frequency spectrum as it is at the upper end. This low frequency performance is important because of the sell-offs that have happened and that are yet to happen in the UHF band. The telecoms companies will pay big bucks for extra transmission space. So the TV channels are getting shuffled away from the top end of the frequency spectrum. Channels 61 to 68 have already gone. Here's an example. This is what's planned for Winter Hill going forward...
Anyone who installed an aerial like this will find their signal strength dropping off as the channels get pushed lower.
For DIY instyall then, using that meter is better than "best guess" and probably worth the money when you're on the roof. But anyone calling themselves professional should really be using something a whole lot better.
* within the performance limits for a log periodic