Hanna Instruments HI 3512 - Manual (Page 12)

12
3 cm
ORP MEASUREMENTS
To perform ORP measurements, connect an ORP electrode (see ACCESSORIES
section) to the instrument and turn it ON.
If necessary, enter the mV mode by pressing RANGE
until the display changes to mV.
Submerse the ORP electrode 3 cm (1¼”) into the
sample to be tested and wait a few seconds for the
reading to stabilize.
Measurements are displayed with 0.1 mV resolution.
The “ATC” (or “MTC”) message is turned off because mV readings are not
temperature compensated.
For accurate ORP measurements, the surface of the electrode must be
clean and smooth. Pretreatment solutions are available to condition the
electrode and improve its response time (see ACCESSORIES section, page 77).
RELATIVE mV MEASUREMENTS
To enter Relative mV mode, press Rel mV function key while in mV
measurement mode. The relative mV reading will be displayed along
with the Absolute mV value and the current temperature readings.
The relative mV reading is equal to the difference between the absolute
mV input value and relative mV offset established in the relative mV
calibration.
Note: If using the pH or ISE electrode while in mV mode, the instrument
will measure the mV generated by the electrode.
ISE MEASUREMENTS
To perform ion concentration measurements, connect an ISE electrode
(and the corresponding reference if necessary) to the corresponding
BNC input and turn it ON.