Underwriters Laboroatories 50 certification was awarded to the user interface for the EZ-Zone ST integrated control loop product from St. Louis-based Watlow. UL 50 certification is the enclosures for electrical equipment standard; Watlow received type 4X indoor approval through UL.

EZ-Zone also is certified to National Electrical Manufacturers Association (NEMA) 250 type 4X standards as a result of recently completed in-house testing. NEMA 250 is also the enclosures for electrical equipment standard. In addition to UL 50 and NEMA certifications, the integrated control loop product is CSA, RoHS, W.E.E.E. and IP65 approved.

EZ-Zone ST integrates temperature control, power control, safety shutdown and power disconnect in a single package. It has a PID temperature controller already connected to a high-amperage solid-state relay with the option of adding a properly sized heat sink, current measurement, an over- and under-temperature limit, a definite-purpose mechanical contactor, and digital communications in one package. The user also has the option of adding a remote user interface for increased usability.