EUTECH INSTRUMENTS CON FM1, Instruction Manual, Page: 8 / 19

5
5 ORP CALIBRATION
This section is applicable for the following models:
•
Eutech Instruments: EC-ORPFM1ST11 & EC-ORPFM1ST21
•
Oakton Instruments: 35649-00 and -05 only
5.1 Important Information on ORP Monitor Calibration
Typically ORP measurements are taken on a relative basis and calibration is not
required. This monitor has ±100 mV offset adjustment, adjustable in 5 mV
increments. Choose a calibration standard that is close to your working condition.
Calibration should be performed regularly to ensure accuracy. Frequency of
calibration will vary and should be checked regularly until the required schedule has
been determined.
Be sure to remove the protective electrode storage bottle or rubber cap of the probe
before calibration or measurement. If the electrode has been stored dry, wet the
probe in tap water for 10 minutes before calibrating or taking readings to saturate the
ORP electrode surface and minimize drift.
Do not reuse calibration solutions after calibration. Dispose of any used calibration
solution. Contaminants in the solution can affect the calibration, and eventually the
accuracy of the measurements.
IMPORTANT: ORP offset adjustment is limited to ±100 mV from the original reading.
Adjustable in 5 mV increments.
NOTE: All new calibration data will over-ride existing calibration data.