Doc,
thats what I was wondering. I'll order one tonight. Obviously that'd be about the only way to know for sure as temp,altitude,barometric pressure would all be different all over the country, so there would be no real "set answer" without running strings through the chrony.
Are there things to take in account when looking for a chrony? I remember reading someone saying they use there's in the basement with a light directly over head for "error" purposes. I suppose I'd like one (if possible) that actually records the string for me and gives me ES,high and low velocity.