AUGUSTA, Maine — The Maine Department of Labor says the state’s unemployment rate dipped to a record low based on preliminary figures for July. Officials say the seasonally adjusted rate was 3 percent. That would be a record unless the final, official figure is adjusted. July’s preliminary unemployment rate was down from 3.4% in the same period a year ago. Maine’s unemployment rate has been below 4 percent for 43 consecutive months, the longest period on record in the state. Maine’s July rate matched that of New England at 3 percent.