(a)      Except in Harford County and Montgomery County, the Governor shall designate and commission one of the three judges of the Court in each county as Chief Judge of the Court. Full power and authority are vested in each judge designated and commissioned as chief judge to act as chief judge. Any writ and other process tested in the name of the chief judge is valid for any purpose.

      (b)      A reference in the estates of decedents law to the chief judge of the court of a county means, with regard to Harford County or Montgomery County, the judge of the circuit court then sitting as the Orphans' Court. A reference to the judges of the court in plural number means, with respect to Harford County or Montgomery County, the judge of the circuit court then sitting as the Orphans' Court, unless the section otherwise specifically provides.