Polymerization reactor systems providing real-time control of the average particle size of catalyst system components are disclosed. The first substrate includes a display part and a sensor part. A plunger is then advanced through the elongated tubular body to disperse the activated sealant into the root canal. The engaging portion has: a guide portion that guides the protrusion portion of the projection portion; and an abutting portion that abuts the protrusion portion. Raised elements along the sides of the base provide the required electrical separation between the conductors during both manufacture and operation. Each of the economizer heat exchangers is configured to inject a portion of the refrigerant into a suction port of one of the compressors.