I don't trust these things to be accurate anyway - it is difficult to tell when you are measuring at TDC. Get the blade close enough with anything, sa ruler, trend thing if it is handy, anything with a scale, or just by eye, then use some scrap. Work up to height if it is the first cut, measuring the depth of cut on the scrap with some verniers or a ruler depending how accurate you need to be. If you are repeating a previous cut keep the final test scrap and use that to reset the blade - much simpler just to swing the blade through, which you can do with a bit of wood, to see when the blades begin to scrape at TDC.