Introduction - Walchem WDP420 Instruction Manual

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INTRODUCTION

The Walchem WPH Series single sensor input and WDP Series dual sensor input controllers are wall
mount pH/ORP controllers that are available in on/off or modulated pulse proportional versions. They
are available with four on/off control relays (WPH410 or WDP410) with two modulated pulse
proportional output and two dry contact relays (WPH420 or WDP420) or four modulated pulse
proportional outputs (WDP340). A fifth output is used as a diagnostic alarm. One or two isolated 4-20
mA outputs are optional.
They are compatible with any amplified electrode. The choice of pH or ORP operation is selected
through the keypad. Use of Antimony pH electrodes is acceptable. Automatic temperature
compensation may be used via a Pt1000 or Pt100 input if pH operation is selected. The controller will
prompt you to calibrate the electrode at the desired frequency. Automatic buffer recognition may be
used in the calibration routine.
Our unique USB feature provides the ability to upgrade the software in the controller to the latest
version.
An advanced USB capability option is available. The Configuration file feature allows you to save all
the set points from a controller onto a USB flash disk, and then import them into another controller,
making the programming of multiple controllers fast and easy. The data logging feature allows you to
save the last 2 month's readings and events to a USB flash disk.
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