I calibrate my Sovereign Meter with a quarter to 500 and not 550. Just my preference but that is what I do. Actually I did it out of ignorance by not reading the manual and just got accustomed to setting it at 500. Should have been right for a meter referred to as a 500 meter wouldn't you think? I would just mess you up if you plan on calibrating yours at 550.
I gathered up a ton of current and old jewelry at my house and air tested everything. Here are some things I found. Most yellow gold items fit into the 400 to 480 range when I calibrated at 500. White gold was in the high 300 range. To give some examples of specifics for me, a yellow gold 14k wedding band of average size always displays right at 450. A 10k band of the same size displayed at about 430. A 10k Class Ring (Mens) displayed at 480. A white gold wedding band 14k dispayed at 380 which really surprized me. I didn't really understand that there was a metallic difference in white and yellow other than the color.
One tip to offer is that you will find that you knock the calibration knob out of wack quite frequently. I wish minelab had a fix for that. What I did to remedy the problem for a quick fix was to use a gold permanent marker, fine tip, and once I got the meter set, I made a mark on the knob at 12 0clock and a mark on the meter housing corresponding to the mark on the knob. When I knock it out of calibration in the field, I can just reallign the marks and off I go without having to drop a quarter and recalibrate.
I remember a post somewhere about the target range on the 550 meter. I will see if I can find it for you.
Jim
DaCHief
