WDP420-122U Walchem (WDP420-122U)
The Walchem WDP420-122U controller is now obsolete and the closest equivalent is the WPH620PSSAN-NN controller. The new WPH600 series has upgraded features; for reference, here is the description of the old model:
pH/ORP controller, w/ 2 pulse proportional and 2 on/off control outputs and diagnostic alarm relay, 120 VAC, pre-wired with 6” pigtails (if on/off) or with 10’ cables for e-class pumps (if pulse), two isolated analog (4-20 mA) outputs, two submersion flat ph electrodes without auto temp comp, integrated datalogging and config file import/export via USB flash stick.
Choose the new model on our WPH620PSSAN-NN page or select a model more suited to your needs from the WPH600 series controller or one of the other pH controllers.