Since you're looking for links, in addition to the Garmin Vector instructions, here are two more videos for how to do a static check for the Power Tap and the Quarq.

I got a friend who works at the university to weigh my barbell weights in the physics lab and write their mass on them with a sharpie. I also could've taken them to a FedEx or UPS or USPS office to get to within an ounce or so. Actually, if my step dad were still working, I could've brought them to the butcher shop. You don't really need NIST weights (all you need is to weigh barbell weights on a scale that's been certified).

20 years ago when power meters were unusual and expensive (and sometimes finicky) we all used to check their accuracy. It was sort of like needing to know how to adjust your own derailleurs, or true your own wheels. We used to call it the "Stomp test" or "the Coggan Stomp" and Coggan described it here: https://forum.slowtwitch.com/Slowtwi...test_P2327677/ That so few do it today, or know that it can be done, doesn't mean that it's hard to do. As I said in my first few posts in this thread, most riders who use a power meter do only one thing: they use it to train their FTP, and training FTP is one of the least demanding things you can do with power data. I didn't say this here but elsewhere I've said that if all you need is consistency (and for many riders that's all they need) then a much cheaper and very consistent device is a wristwatch. Just time yourself over a regular course, check the weather service for windspeed and direction, and write it all down in a notebook. Over time you'll figure out whether you're getting faster or not. That's how riders have trained pretty effectively for more than a century.