So, this is interesting....
After deciding that the refractometer was off by using the home-made recipe discussed above, I decided NOT to make any changes until I could pick up a bottle of the pinpoint 53 ms solution and get a "third opinion". I'm glad I waited
When I calibrate the refractometer with the 53ms solution, I discovered that my home-made solution was off, and that my original calibration was correct! It now reads distilled water at 0ppt and the 53ms solution is 35ppt. So, I guess I can draw several conclusions
#1) It looks like I got a dead-on refractometer after all!
#2) It pays to check, double check and quite often triple check the calibration of stuff.
#3) I proved that I can make the wrong solution exactly the same 3 times in a row and all that it proved was none of my wife's kitchen measuring utensils are as accurate as they should be. My confidence in the next batch of gravy is going to be a little shakey
