It does not state that it is NSF, so for commercial application - i'd guess not. For home use, I don't see why not - that's what I'm going to use it for. I want to understand more about the acidity of my sourdough over fermentation time, in addition to some other home applications.. I have not tried it yet - I'm making dough tonight or tomorrow so Ill see how it works and report back.
As for calibration, the unit can be internally calibrated up to 3 points by testing in buffer solution. They sell this at Home Depot, some grocery stores, pool supply stores, etc. I neglected to buy some at time of purchase and the Ph solution kit that I have is expired. I plan to pick one up today as factory calibration should be initially verified.