The Walchem WCT400-141N controller is now obsolete and has been replaced by the WCT400-141U controller which now has integrated USB datalogging and software upgrade capability. Otherwise, both the WCT400-141N and the WCT400-141U have the same specifications with bleed & feed, 120 VAC, prewired, isolated 4-20 mA output, graphite electrode & tee , 20 ft cable (for in-line or submersion mounting).
Please click here to view and/or purchase the new replacement controller and to view literature.