TRENTON The New Jersey Supreme Court appointed a special master to conduct a hearing on the reliability of the machine that is replacing the Breathalyzer throughout New Jersey. The order also lifts the freeze on some of the hundreds of drunken driver prosecutions that were put on hold by judges after defense lawyers raised concerns about the new machine. The state’s highest court entered the dispute on its own accord and changed a course set Dec. 1 by an appellate panel. That panel had ordered a trial judge in Middlesex County to conduct a hearing on the new machine, the Alcotest 7110 MKIII-C. The Supreme Court appointed a retired appellate judge, Michael Patrick King, as special master. Hundreds of DWI suspects have their cases on hold. Alcotest evidence has not been allowed in Middlesex County since the fall, and in Morris and Union counties since Monday. A similar order was pending for Burlington County this week. Unlike the Breathalyzer, the Alcotest automatically takes readings. It uses two independent, simultaneous methods to analyze a suspect’s breath to determine the level of intoxication: infrared light and an electrochemical reaction. It automatically produces a printout with both readings. The Breathalyzer requires its operator to compare the difference in the amount of light coming from two tubes of chemicals. The suspect’s breath is introduced to one tube, which darkens if alcohol is detected. Statewide, 76,502 DWI cases have been brought over the past two years, and 6,505 are pending.