Thermo Fisher Scientific pH/ORP/Conductivity Field Monitors - Manual (Page 9)

6
5.2 ORP Calibration
1. Plug in the ORP monitor to turn on. The monitor will
be in ORP measurement mode.
2. Rinse the probe thoroughly with de-ionized water or
a rinse solution. Do not wipe the probe; this causes
a build-up of electro-static charge on the surface.
3. Dip the probe into the calibration standard. The end
of the probe must be completely immersed into the
sample. Let probe soak 2 to 5 minutes or until
readings stabilizes.
4. Press the CAL key to enter the calibration mode.
"CA" will flash on the display for a second and then
a value close to the calibration standard will flash.
5. Press the
S or T keys to adjust the display to
match the calibration standard value. Press the
ENTER key. "CO" will flash on the display. The
reading should now display the same value as the
calibration standard. See Figure 3.
Immerse ORP electrode into
a calibration standard solution,
for example, 255 mV
Press
Press
Press
Figure 5 - ORP
Calibration Procedure