Hanna Instruments HI 121 - Manual (Page 44)

44
m V CALIBRATION
( f o r t e c h n i c a l p e r s o n n e l o n l y )
• Press CFM to confirm. The instrument returns to
measurement mode.
Note: If the reading is not close to the selected calibration
point, “WRONG” tag will blink. Change the
temperature probe and restart calibration.
All the instruments are factory calibrated for mV.
Hanna’s ORP electrodes are interchangeable and no mV calibration is
needed when they are replaced.
If the measurements are inaccurate, mV recalibration should be performed.
For an accurate recalibration, contact your dealer or the nearest Hanna
Customer Service Center, or follow the instructions below.
A two or three-point calibration can be performed at 0.0 mV, 600.0 mV
and 1800.0 mV.
• Attach to the BNC connector (#8 on page 4 and 5 for pH channel or
#6 on page 4 and 5 for ISE channel) a mV simulator with an accuracy
of ±0.1 mV.
• With the instrument off, press and hold down CFM & LOG keys for pH
input channel calibration or CHANNEL & RCL keys for ISE input channel
calibration, then power on the instrument. The “CAL” tag will appear
and the secondary LCD will show 0.0 mV.
• Set 0.0 mV on the simulator. When the reading is stable and close
to the selected calibration point, “CFM” tag will blink.
• Press CFM to confirm. The secondary LCD will display 600 mV.
• Set 600.0 mV on the simulator. When the reading is stable and
close to the selected calibration point, “CFM” tag will blink.
• Press CFM to confirm. The secondary LCD will display 1800 mV.
• Set 1800.0 mV on the simulator. When the reading is stable and
close to the selected calibration point, “CFM” tag will blink.
• Press CFM to confirm. The instrument returns to measurement mode.
Notes: • If the reading is not close to the selected calibration point,
“WRONG” tag will blink. Verify calibration condition or contact
your vendor if you can not calibrate.
• Press CAL in any moment of the calibration process. The
instrument will return to measurement mode. If calibration
process is stopped after 600 mV is confirmed, the 600 mV range
is calibrated and calibration parameters are memorized.
CFM