Violin Making Academy

Hi all! I'm new to violin making and I've been having some difficulties with my calliper. Admittedly, it's a relatively cheap model from China (costing about 80 EUR instead of 500 EUR), so that might be part of the problem, but I hope it is solvable. As you can see, the dial points at about the '91' below zero when it's not measuring anything. I want it to point at dead 0, so that I'm sure I interpret the measurements correctly (for now I've been adding about 0.9 mm to every measurement in my head, which is tiresome and prone to mistakes). Does anyone know how to reset the resting position to zero? I can turn the dial plate anticlockwise (to the left), but then the zero isn't at the top anymore, which is also confusion to me. I'd like the dial itself to point straight up, at zero. Thank you in advance and best wishes 🥰

Hi everyone, I hope you all are fine. I have recently watched the "setting the UV box" video and maybe I missed something, but I don´t remember to have listened what kind of UV lamps is better to use, specially relating to which wavelength is the correct; also if LED lamps are good for curing and tanning the violin wood. Thanks for reading, all comments welcome!