***NEW*** MILLROCK TECHNOLOGY introduces a Resistivity Monitoring System for determining the frozen state of a material during the freeze drying process. The resistivity of a substance dramatically increases as a solution changes state from a liquid to a solid. By monitoring the resistivity of a solution during Freeze Drying, the freezing point and melting point can be determined. The monitoring system is integrated with the PLC control system to determine the freezing point and then prevent product melt-back during the drying cycle. Millrock has developed unique resistivity sensing probes that can be used in vials as small as 2 ml.