Hanna Instruments HI 23 Series, Instruction Manual, Page: 32 / 60

32
CALIBRATION
The controller is factory calibrated for temperature as well as
for the analog input and outputs.
The user should periodically calibrate the instrument for EC
or TDS. For greatest accuracy, it is recommended that the
instrument is calibrated frequently.
Before beginning normal operation, it is recommended to
standardize the probe with the Hanna calibration solution
close to the expected sample value and inside the selected
range.
EC AND TDS CALIBRATION
The calibration points for EC and TDS are as follows:
Range Calibration point(s)
0.0÷199.9 µS/cm 84.0 µS/cm
0÷1999 µS/cm 1413 µS/cm
0.00÷19.99 mS/cm 5.00 - 12.88 mS/cm
0.0÷199.9 mS/cm 80.0 - 111.8 mS/cm
0.0÷100.0 ppm 42.0 ppm
0÷1000 ppm 800 ppm
0.00÷10.00 ppt 6.44 ppt
0.0÷100.0 ppt 55.9 ppt
The user should select the appropriate range to calibrate (setup
code 03). Calibration must be performed for each range used.
The temperature probe should also be connected to the pro-
cess meter (when using a different temperature probe). The
meters are equipped with a stability indicator. The user is also
guided with indications on the display during the calibration
procedure.
Initial Preparation
Pour a small quantity of the calibration solution (e.g. 1413 µS/
cm) into a beaker. If possible, use a plastic beaker to mini-
mize any EMC interference.
For accurate calibration use two beakers containing the same
solution, the first one for rinsing the probe, the second one
for calibration. By doing this, contamination between the so-
lutions is minimized.