Hanna Instruments HI 121 - Manual (Page 24)

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CFM
• The calibrated value will be displayed on the primary LCD and the
second expected standard solution on the secondary LCD.
Note: The instrument will automatically skip the standard used for the first point.
• After the first calibration point is confirmed, immerse the ISE electrode
approximately 4 cm (1½”) into the second standard solution.
• If necessary, press the ARROW keys to select a different standard solution.
• The “ ” tag will blink on the LCD until the reading is stable.
• When the reading is stable and close to the selected
standard, the “CFM” tag blinks.
• Press CFM to confirm calibration.
• The instrument stores the calibration value and
returns to normal measurement mode.
Note: • If the mV value is out of mV range (±2000), “WRONG”
“BUFFER” tags will blink. In this case check if the correct
standard has been used, or refresh the electrode by following
the maintenance procedure (see page 51). If necessary,
change the standard or the electrode.
• Slope window is between ±20 mV and ±105 mV if ion charge
is not specified (undF selected in SETUP menu) or between 50%
and 120% of default slope for the corresponding ion charge.
Default slope value (mV/decade):
–59.16 (monovalent anion) - ion charge is –1
59.16 (monovalent cation) - ion charge is 1
–29.58 (divalent anion) - ion charge is –2
29.58 (divalent cation) - ion charge is 2
100 - ion charge is “undF”
• Press CLR or 2nd then CLR key during calibration if you want to
clear calibration parameters and set to default. The instrument will
display “CLR” message and will return to measurement mode.
• Press MODE to display the temperature reading on the LCD during
calibration.
ONE-POINT CALIBRATION
• Press CAL after the first calibration point was confirmed.
The instrument memorizes the one-point calibration
parameters and returns to measurement mode.
CAL