Hanna Instruments HI 21 Series - Manual (Page 25)

49 48
Note In any moment, by pressing LCD or CAL DATA the meter will
return to the regular operating display.
• Press or to view the time of last calibration. The sec-
ondary display will show "HOU" to indicate hours.
• Press or again to view the offset in mV at the time of
last calibration. The secondary display will show "OFF" to
indicate offset.
• Press or again to view the first slope in mV at the time
of last calibration. The secondary display will show "SL1" to
indicate first slope.
• Press or again to view the second slope in mV at the
time of last calibration. The secondary display will show
"SL2" to indicate second slope.
• Press or again to view the first memorized buffer at
the time of last calibration. The secondary display will show
"BUF1" to indicate first buffer.
LAST CALIBRATION DATA
The meter stores the following information about last calibration in
the EEPROM:
• Date
• Time
• Offset in mV (for HI 21 only)
• Up to two slopes (for HI 21 only)
• Up to three buffers
While displaying this data, the pH controller remains in con-
trol mode.
The procedure below indicates the flow for a three-point cali-
bration. The sequence will vary if fewer calibration points are
used (e.g. for a one-point calibration the following data will
be displayed: date, time, offset, first slope, buffer 1 value).
For the HI 22, last calibration data includes date and time
of calibration and the values of the 2 calibration points. Dis-
playing of these items follows the above sequence.
• To begin the cycle press CAL DATA. The last calibration
date will appear on the main LCD display as DD.MM for-
mat, while the secondary display will show the year.
If the meter has never been calibrated or an EEPROM reset
has occurred, no calibration data is shown when CAL DATA
is pressed. The “no CAL” message will blink for a few sec-
onds, then the meter skips back to normal mode.
• Pressing will cycle through the fol-
lowing steps in reverse order, i.e. last
buffer.