EUTECH INSTRUMENTS ORP ELECTRODE User manual

INSTRUCTION SHEET FOR
ORP ELECTRODE
INTRODUCTION
ORP electrodes use inert platinum or gold as their sensor element. A double-junction ORP
electrode has an internal reference element which is isolated within a second chamber,
minimizing contamination from sample media containing sulphides. They are designed for
maximum reliability, accuracy, and ease of use. The electrodes are housed in a high-grade epoxy-
body or Ryton housing resistant to a wide range of solutions and come with a BNC connector in
different cable lengths. These ORP electrodes are recommended for precision ORP/Redox
measurement in laboratory and for on-line applications.
Unlike pH electrodes, ORP electrodes cannot be standardized against buffers. Like pH electrodes,
ORP electrodes are subjected to coating and abrasion by the measured media and in some
instances are poisoned by chemicals which may be present. To improve the reliability of ORP
measurements and performance, testing of ORP electrodes in standard potential solutions helps
determine if electrodes are responding correctly or need maintenance.
PREPARATION & CHECKING OF ELECTRODE
Set instrument to millivolt (mV) mode. Check the electrode with 475mV ORP solution. It should
read 475mV ±25mV @ 25oC. Please dry the electrode sensor in air before taking reading. If it
does not read properly, clean electrode as mentioned below.
CLEANING OF PLATINUM PIN
Flush ORP electrode with deionized water and immerse in bleach for about 30 minutes. Repeat
cleaning procedure if reading is out of specification.