I do find her website a little bewildering so I can see why you would react with such a mindset. But a minute googling answers most of your questions: https://

I do find her website a little bewildering so I can see why you would react with such a mindset. But a minute googling answers most of your questions: https://tamararubin.com/2016/12/ask-tamara-what-do-you-use-to-test-for-lead/ https://tamararubin.com/2016/12/ask-tamara-what-do-you-use-t... It seems like there's a misunderstanding about the technique being used. An XRF gun is a portable device that works in the field and does not require to be operated in a lab. For most of the consumer goods she is testing she is already using a highly sensitive piece of equipment that measures ppb- it wouldn't make sense to "send it to a lab". She is certified in using the equipment and probably one of the most experienced at using it to test consumer goods. The gun she is using is self-calibrating to begin with, but still calibrated for each test. I actually think most of the problem here is that her website has an unprofessional appearance. If it had the professional appearance you were expecting and she had a university degree in chemistry or material science but posted almost the exact same information with perhaps a few minor edits and a slightly different style I think it would have the scientific look and feel you and others are looing for. But the underlying science of using an XRF gun to test for lead seems quite sound.