Hi Manfred-
Nice utility, thanks! I have just donated.
A suggestion...
Add a method to set the number of ticks on the scale arc- eg .SetTicks(Int)
At the moment it automatically does so based on the size of the image.
This means the ticks may not relate to the scale of the gauge.
For example, the default 10 ticks on a 10000 full scale relate to 0,1111,2222,.......8888,9999
.SetTicks(11) would match 0,1000,2000,........9000,10000
.SetTicks(21) would match 0,500,1000......,9500,10000