The Walchem WCT300-5NN controller is now obsolete and has been replaced by the WCT400-5NNU controller which now has integrated USB datalogging and software upgrade capability. Otherwise, both the WCT300-5NN and the WCT400-5NNU have the same specifications with bleed & feed, hardwired, cable glands, no 4-20 mA output, no electrode.
Please click here to view and/or purchase the new replacement controller and to view literature.