The Walchem WDT300-1N2 controller is now obsolete and has been replaced by the WDT400-1N2U controller which now has integrated USB datalogging and software upgrade capability. Otherwise, both the WDT300-1N2 and the WDT400-1N2U have the same specifications with 120 VAC, prewired, no 4-20 mA outputs, two graphite electrodes & loose flow switches, 20 ft cables.
Please click here to view and/or purchase the new replacement controller and to view literature.