I'm going around and around over s dealership that allegedly changed the antifreeze on her van. First and foremost I use a Refractometer, it indicates -84 F, as in off scale. They are using floating ball tester. The other test I do it an Electrolysis test, you put one meter probe in the Coolant tank, the other on the negative battery terminal. Anything 0.3 VDC or more serious damage is occurring. I'm at 0.225 VDC was at 0.221 before the coolant change. They are saying this is Junk Science. BTW I can't get any Ph reading with my electronic detector. On my F-150 I get 0.038 VDC and -34 F with Refractometer, this is a recent flush, clean and fill I did.